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Please note: This is just a mirror of the comp.os.cpm CP/M FAQ maintained by Trevor Gowen. Check out the original file at


CP/M Frequently Asked Questions

Table Of Contents

Q0: Introduction - What is CP/M? And why should anybody care?

Q1: I just became a proud owner of a cool old machine.....

Q2: I'd like to sell/find a home for my old computer. What is it worth?

Q3: Does CP/M stand for anything?

Q4: What ever happened to Digital Research and Gary Kildall?

Q5: Is CP/M in the Public Domain?

Q6: Where are the CP/M archives?

Q7: Can I subscribe to com.os.cpm via E-Mail?

Q8: What languages/compilers/databases/editors are still available?

Q9: Where can I find Z80 math routines?

Q10: What new CP/M computers are available?

Q11: What is this I hear about a CP/M CD ROM?

Q12: How can I transfer my CP/M files to DOS?

Q13: How can I convert an (insert name) disk to (insert name) format?

Q14: Can I read my 8" disks with my PC?

Q15: Where can I buy new diskettes?

Q16: Can I use the newer floppy drives on my old machine?

Q17: Can I run CP/M on my MSDOS/UNIX/68K machine?

Q18: Where can I get a boot disk for (insert system name)?

Q19: What terminal emulation programs are available?

Q20: How do you unpack a .ARK or .ARC file?

Q21: How do you unpack a .lbr file?

Q22: What are all these .xQx, .xYx, and .xZx file types?

Q23: Are any of these .ARK, .LBR, or CRUNCH utilities on MSDOS?

Q24: Why does my Kaypro drop characters above (insert baud rate)?

Q25: What is an Advent TurboROM?

Q26: How can I add a hard drive to my CP/M Machine?

Q27: What belongs in the unpopulated board area on a Kaypro?

Q28: What is The Computer Journal?

Q29: Are there other magazines supporting CP/M?

Q30: Does anybody support Amstrad machines?

Q31: Does anybody support Sharp Machines?

Q32: What is ZCPR and the Z System?

Q33: What ever happened to the Z800?

Q34: What is the status of the Z380?

Q35: What is the KC80?

Q36: What is the S-100 bus (also known as IEEE-696 bus)?

Q37: Anyone know a good source for cross assemblers?

Q0: Introduction - "What is CP/M? And why should anybody care?"

A: (Trevor Gowen, Lee Hart)

[FTG] - Almost 30 years ago I began to write computer programs as a young scientist at University in the U.K. For useful work the only choice was mainframe based high-level languages such as Algol and Fortran (recently "standardised" in 1966). At the lowest level I learnt "machine code" on a PDP-8S - booting up consisted of toggling in a dozen or so instructions via binary, front-panel, switches to enable a simple punched tape reader; an improved tape loader would then be read, finally allowing loading of a "highish" level language (interpreter?) - FOCAL (I hope I've got the name right), a little like the later BASIC. This process took about 15 mins. of the 30 mins. "slot" allocated - if you were lucky!
The nearest one (as a user) got to an "operating system" (as we now understand the term) was the "job control language" (JCL) required to submit a program for execution on the mainframe. This was as much concerned with the charging of run-time and resource costs to the "user" as well as the running of the program. On some mainframes (notoriously I.C.L.'s in the U.K.) it was perfectly possible to write a simple, but useful, FORTRAN program that was shorter (in terms of the line number required) than the lines of JCL needed to set up the job!
By the time I'd finished my post-graduate studies and began gainful employment single-board "microcomputer development systems" had begun to appear as well as mini-computer systems with their compact (cf. mainframes) disc-drives eg. DEC's PDP-11 variants. I became familiar with my first operating system at this point, and the file system utility, PIP, later to (re-)appear within CP/M - I'll pass over to Lee now ...
"CP/M was the first generic operating system for microcomputers. Without CP/M, every brand of computer had its own unique operating system(s). Programs could not be shared between computers. Software had to be rewritten for each different type of computer.
One solution is to make all computers alike (what we do today). But this locks computer hardware into a rut. It becomes very difficult to make improvements, because each new model has to have hardware identical to all the old computers or the old software won't work.
Another solution is to force users to buy new software every time the hardware is upgraded (again, what we do today). But this is expensive; you have to keep reinventing the wheel, as the hardware and software gets redesigned every few years.
CP/M showed us another approach. CP/M is an Operating System; a set of programs that hide the differences between computers. Then all computers look the same to any program. You could buy a word processor (like Wordstar) or a spreadsheet (like Supercalc) or a high level language (like BASIC) and it would run on any computer running CP/M.
At its height, CP/M was the second most popular operating system on every computer (after the manufacturer's own proprietary operating system). Because it was also a complete software development environment, CP/M also enabled you to write software that was machine-independent, and indeed, even to move CP/M itself to other computers.
CP/M is still important because it is the model that shows that the present way we handle computer hardware and software is not the only way."
[FTG] - In the U.K. CP/M became known as an industrial standard o.s., especially for process-control micro-computer systems. It was probably more well known however as the underlying o.s. for the Amstrad CPC and PcW series of "home computers" and "word processors".

Q1: I just became a proud owner of a cool old machine.....

A: (Herb Johnson, Tim Shoppa)

So you have aquired an old system, not one of the all-in-one systems like Kaypros or Osbornes, but rather one with lotsa cards in a cardcage. But... no disks, no manuals, maybe even no hard or floppy drives. "Hey, *I* remember these systems! I've always wanted one of these!" you say. And now you need some help to get it running.
We hate to sound discouraging ­ we like to help owners of old equipment after all ­ but we also want to set people's expectations before they spend a lot of time and/or money. We need be clear as to what it takes to "own" an older, pre-IBM PC system.
You will need to have some degree of knowledge of digital electronics, and have some electronic test equipment. Do not expect "the net" to instantly give you the knowledge to fix all your problems. There is no consensus about the amount of knowledge or equipment: a VOM for sure, a scope is reasonable, a logic analyzer... probably not. You will learn from the experience of debugging and maintaining an older system.
You will discover that these systems may not be amenable to using IBM PC stuff, that they may need 8-inch floppy drives, that these systems may not support hard drives. In some cases, these systems may not even run all that well even with the original 8-inch drives or wierd hard disk controllers! When you also discover you can't get the parts without spending more money, you may lose interest.
To most people these days, a BIOS by definition is in ROM, so it automatically comes with the hardware. You will learn that the CP/M BIOS gets loaded off the boot floppy and lives in RAM. You'll need BIOS source code to do any tinkering, and you may have to disassemble it to obtain the source. And other documentation like manuals may be hard to obtain.
So we'll help you in your search for the original boot disks, the original type of floppy drives, and some software to run, but don't think you'll just add a hard drive and some (5.25-inch) floppy drives and off you'll go!

Q2: I'd like to sell/find a home for my old computer. What is it worth?

A: (Herb Johnson)

Make a list of what you have to offer: computer types, features, and conditions. if it's a bus-based system, what cards are in it? Find all the docs and disks, particularly the boot disks. Check the system out if you can, and make *multiple copies* of the boot disks. Put one in the disk drive, one with the docs. Take notes.
Weigh the system, its floppy drives and its documents and disks (separately if they are heavy); decide if you want to ship or just want local pickup. If you ship, you will have to pack it carefully and take it to the shipper. Figure 25 to 50 cents a pound shipping.
Post a message in comp.os.cpm describing your system, its condition, and where you are located. Disclose any special conditions the new owner should know: "museum quality", "good for parts", "local pickup only", "cost of shipping", "will help you", whatever. Owners often recount their history of use to add a human dimension to it and often makes negotiations smoother and faster. You'll eventually end up working through all this anyway, so why not do it up front?
You'll probably get some replies that will inform you on what you have and the level of interest in it. Use your common sense about all this. One virtue of offering old computers is that their minimal value will not be of interest to scam artists!
You can try to donate your computer to a school or charity but they will most likely refuse or junk it. There is so much IBM-PC compatible stuff around that is considered preferable, and IT gets junked most of the time! If you put an ad in the newspaper be prepared for a lot of "will it run Windows?" phone calls. You can take it to a hamfest or flea market, but you may end up abandoning it at the end of the day.
What is it worth? Generally, the answer is cost of shipping. Prices are based on the interest of the buyer and the (dis)interest of the seller. There is no "blue book". People will offer, and some even pay, hundreds of dollars for rare systems such as a MITS Altair 8800. Most likely, unless your system is very special, you are competing with people who will give away similar systems to a good home. If you are trying to make money, do your homework and check for previous sales and requests across the Internet, and use your business judgement.

Q3: Does CP/M stand for anything?

A: (Don Kirkpatrick)

There are at least three popular answers ­ Control Program for Microcomputers, Control Program for Microprocessors, and Control Program/Monitor. The issue is clouded by authors of popular CP/M books giving different answers. According to Gary Kildall (the author of CP/M), in response to a direct question on the PBS show "The Computer Chronicles" following Computer Bowl I, the answer is: Control Program for Microcomputers. This is also consistent with DRI documentation. See, for example, p. 4 of the DRI TEX manual.

Q4: What ever happened to Digital Research and Gary Kildall?

a: (Don Kirkpatrick)

DRI was bought out by Novell and subsequently sold off to Caldera, which currently owns the copyright to all DRI software.
Personal computer pioneer Gary Kildall, who but for a single failed business deal might have enjoyed the wealth and fame of Bill Gates, died July 11, 1994, in a Monterey hospital at age 52.
Kildall was taken to the hospital after suffering a concussion in a fall. Evidence indicates Kildall suffered a fatal heart attack. It is unclear if the two conditions were related.

Q5: Is CP/M in the Public Domain?

A: (Jay Sage, Don Maslin, Tilmann Reh, Kirk Lawrence, Tim Olmstead)

On Sept 10, 1996, Caldera, the company that bought all of the Digital Research assets from Novell. They have released all of the source code for DR products.

The last source for new, legal copies of CP/M (with documentation, $9, plus shipping), is:

California Digital, Inc.
17700 Figueroa Street
Gardena CA 90248
310-217-1951 Fax

There exists a privately maintained web site with many DRI programs and manuals. (Caldera/Lineo is aware of this site and has given its permission to present the material.) Available for download are:
CP/M 2.2 (binary, source, manuals)
CP/M 3.0 (binary, source, manuals)
CP/M-68K (binary for v1.2, and v1.3, no manuals yet)

The software is licensed free to non-profit users. This includes individual users. Commercial licenses are available, but without any form of support. The address of the site is:

On the other hand, there have been lots of greatly improved clones, including ZCPR3 for the command processor and several replacements for the BDOS. Some of these are commercial (e.g., ZSDOS/ZDDOS), but many have been released to the public. Most of the latter can be obtained from and many BBSs.
There is also a CP/M-Plus replacement named ZPM3, written by Simeon Cran. It offers much more performance and some additional features compared to CP/M-Plus. An extended CCP, the ZCCP, is also available. Unfortunately, it still seems to have some bugs. ZPM3 and ZCCP are free! However no sources as Simeon won't give them away.
New legal copies of CP/M-86 were still available, for $75, from:

DISCUS Distribution Services, Inc.
17607 Vierra Canyon road
Salinas, CA 93907-3312
(408) 663-6966

And CP/M-68K is available from:

James Knox
1825 East 38 1/2
Austin, TX 78722
(512)473-2122 (FAX)

Q6: Where are the CP/M archives?

A: (Don Maslin, Ralph Becker-Szendy, Paul Martin, Ulrich Hebecker)

Simtel20 is no more. Six sites that stock CP/M files are: (unfortunately down - February, 2001)

As of 25 March 1998, people have been reporting difficulty reaching the site and it may be no longer.
The main archive is Assuming the availability of anonymous ftp, look into the subdirectories of /pub/cpm. There is a *lot* there! One of the first directories to check is starter-kit. It contains everything you need to get up and running.
If you wish to submit material to, contact:

Jeff Marraccini
Senior Computing Resource Administrator
Oakland University
Rochester, MI USA 48309-4401
(810)370-4542 <- Work

He will send you instructions and passwords necessary to perform an ftp upload. specializes on CP/M programs for the DEC Rainbow, but has also some generic CP/M software such as a Micro Emacs, the HI-TECH Z80 C compiler and a few games. Questions about this site can be directed to Tom Karlsson, <tomk@Student.DoCS.UU.SE>, the site administrator.

There is a European file server group, named TRICKLE. This group mirrors oak.oakland and other archives. For more information, get in touch with your local TRICKLE operator.

Q7: Can I subscribe to com.os.cpm via E-Mail?

A: (Keith Petersen)

To join the CPM-L mailing list, which is gatewayed to and from comp.os.cpm, you must send email to the list server. If you are on BITNET, send the following command:

SUBSCRIBE CPM-L your full name

to LISTSERV@RPITSVM. You can send that in an interactive if your system supports them (e.g. the CMS TELL command), or in the body of a mail message (*not* the subject line).

If you are not on BITNET, the Internet subscription address is LISTSERV@VM.ITS.RPI.EDU. Send mail to that address with this text in the body of the message:

SUBSCRIBE CPM-L your full name

!!! This information is not valid any more !!! !!! The newly installed mailing list can now be subscribed to at!!!

Q8: What languages/compilers/databases/editors are still available?

A: (Ralph Becker-Szendy, Ulrich Hebecker, Jay Sage, Gene Buckle)

Unfortunately, SLR sold out to Symantec and all products except for one DOS (or Windows) tool have been withdrawn from the market (what a shame). However, The Computer Journal does carry the excellent ZMAC package including a macro relocatable assembler, linker, and librarian. Except for the speed, ZMAC is better and cheaper than the standard SLR tools.

MIX C and other MIX products are available from:

Ed Grey
P.O. Box #2186
Inglewood, CA 90305

Hi-Tech C V3.09 for CP/M is now freeware. The authors are still maintaining their copyright, but are allowing free use for both private and commercial users without royalty. The original is on their bbs in Australia, at +61 7 3300 5235. Copies can be obtained from:

Hi-Tech also offers a Z80 cross compiler for DOS or Unix supports compilation of CP/M programs. The cross compiler is commercial software, but a working demo is available from their ftp and web servers.

The Computer Journal still offers BDS C, in both the original, straight CP/M version and in a version that includes Z-System support. The package, with both versions of the compiler and a very large manual, is only $25.

Micro Emacs is available from:

Public domain CP/M programs are available via:

Elliam Associates
Box 2664
Atascadero, CA 93423

In the past, Elliam has sold Turbo Pascal, Uniform, Nevada COBOL, SuperCalc, and much more. Call for availability and price.

WordStar 4.0 is available from:

Trio Company of Cheektowaga Limited
3290 Genesee Street
P. O. Box 594
Cheektowaga, NY 14225-0594

Dynacomp stills sell CP/M software (or to be accurate, they still had several dozen CP/M programs in the 1992 catalog.) It is the kind of programs which ought to be written in BASIC: Typing tutors, little engineering programs like calculation of the stiffness of beams, education math programs. Their address is:

178 Phillips Road
Webster, NY 14580
(800)828-6772 orders
(716)265-4040 support

There is no known U.S. source to purchase the following programs:
Any Microsoft product (M80, L80, F80, Pascal, BASIC)

Most have been "abandoned" by their makers, but not placed in the public domain. There is now a site specializing in making available commercial abandoned software. You may find a copy of what you seek at The Commercial CP/M Archive:

For our European readers, much is available in Germany. dBASE, WordStar 3.0, Multiplan 1.06, SuperCalc PCW, and Microsoft Basic (Interpreter and Compiler), M80, L80, CREF80 , and LIB80 can be ordered in either PCW format or C128 (also native 1571) format from:

Wiedmann Unternehmensberatung & EDV-Handel
Hauptstrasse 45
73553 Alfdorf
Tel: +49-7172-3000-0 (Inside Germany use 0-7172...)
Fax: +49-7172-3000-30

They are marketed as "for the C128", however the disks are in KAYPRO IV format, and since the C128 uses the same screen codes as ADM-31 or KAYPRO, it's probably interesting for people with other CP/M machines as well. Everything is said to come with a German language manual and each one is offered for app. EUR 76.50 , including sales tax of 16%, which you could probably somehow get a refund on if living outside the EC.

Z3PLUS (for CP/M 3.0) and NZCOM (for CP/M 2.2) Z-Systems and manuals can be downloaded from
Additional tools, the complete Z3COMs and ZHELPs and Juggler 3.5 with Amstrad CPC Vortex and PCW CF2DD Support (3.5" only) (used to be EUR 25.--, now free!) can be downloaded from:
or ordered on CD via

Helmut Jungkunz
Wirtstr. 10
81539 Muenchen, Germany
Tel.: +49.89.69737382

and C128 CP/M Plus (app. EUR 40.-) from:

Schaltungsdienst Lange Berlin
Tel.: 030/7036060

VDE is a very popular free editor that uses WordStar key bindings. It can be obtained from

for a plain vanilla CP/M system or

for those running a Z-system.
ZDE (version 1.3 and above), the successor to VDE, written for Z80 CPUs, should be preferred in that case. It can be downloaded from most online CP/M resources.

Q9: Where can I find Z80 math routines?

A: (Roger Hanscom, Hal Bower)

Programmers looking for examples of commonly used Z80 assembler routines may want to look at "Z80 Assembly Language Subroutines" by Leventhal and Saville. It was published by Osborne/McGraw-Hill in 1983 (ISBN 0-931988-91-8), and it 497 pages long. It also contains general programming information, as well as a summary of the Z80 instruction set and reference data for the Z80 PIO. Assembler routines given in the book fall into the following categories:
- code conversion-array manipulation and indexing
- arithmetic -bit manipulation and shifts
- string manipulation-array operations
- I/O-interrupts
For transcendental routines, it is generally better to use a high level language, such as Hi-Tech C, where they are built-in.
Basic 16-bit four-function math (add, subtract, multiply and divide) are available in source code as modules within the SYSLIB collection of utilities (SMTHxx). SYSLIB Version 3.6 is freely available, and Version 4.x was released in source and linkable (SYSLIB.REL) form for non-commercial use only. Joe Wright still holds the copyright as Alpha Systems as far as I know, and Hal Bower has maintained the code since circa 1987.

Q10: What new CP/M computers are available?

A: (Ralph Becker-Szendy, John D. Baker, Tilmann Reh, Ramon Gandia, Hal Bower)

The YASBEC (uses a 64180, has SCSI interface), written up in TCJ, issues #51 and #52. It is important that the YASBEC uses a proprietary bus system.

The CPU280 (uses a Z280, an IDE interface is available), also written up in TCJ, issues #52 and #53. Circuit boards are available from The Computer Journal. CPU280 uses the ECB-bus which allows many other I/O cards to be connected.

Ampro LittleBoard products are no longer available from Dean Davidge nor are the SB180/SB180FX from Micromint.

Another CP/M machine is the PalmTech CPUZ180, designed and built in Australia. The complete SBC fits on a 6"x4" and runs at 18MHz. Included are floppy and IDE hard disk controllers, color/monichrome video controller, IBM PC/XT keyboard interface, printer parallel port, two serial ports, real time clock, 1 Meg ram, amd many other features.
It may be ordered from:

Ramon Gandia
Anvil Technology
Box 970, Nome, Alaska 99762-0970
tel. 907-443-7199 or 907-443-2437
fax. 907-443-2487

And the P112 from D-X Designs Pty Ltd is a single board CP/M compatible computer with the footprint of a 3.5" floppy disk drive. It provides a Z80182 (Z-80 upgrade) CPU with up to 1 MB of memory, serial parallel and diskette IO, and realtime clock in a 3.5-inch drive form factor. Powered solely from 5V, it draws 150mA (nominal: not including disk drives) with a 16MHz CPU clock. Details can be found at:

Q11: What is this I hear about a CP/M CD ROM?

A: (Jack Velte)

The disk is no longer being offered by Walnut Creek. However, copies of it are available for $30.00 each, including shipping, from:

Timer Saver
521 Sycamore Dr
Windsor, CO 80550


It contains over 19,000 files with executable programs, source code, documentation, and other materials. Included are the the entire Simtel20 pub/cpm archives, the contents of some major bulletin boards, and the personal collections of several leaders in the CP/M community. You'll find:

Assemblers, compilers, code libraries, and programming tools Editors, word processors, spreadsheets, calculators Disk, printer, modem and other system utilities Archive and compression tools Telecommunication software for users and BBS operators Articles from user's group journals and other publications Games and educational software Help files

You'll also find CP/M emulators and other tools for working with CP/M files under DOS, OS/2, and Unix. Most programs include not only documentation but also complete source code. Programs for all different computers are on the disc: Kaypro, Osborne, Commodore, Amstrad, Starlet, and others. This disc comes with a MSDOS view program which allows you to view, decompress, or copy files to your disk. It's fully BBS'd with description files compatible with popular MSDOS BBS programs.

A spokesman for Walnut Creek said that it is just not feasible for them to have another run made. When asked specifically about having a few made privately, the spokesman said the entire disk is public domain and freeware, and that Walnut Creek doesn't need to give permission to have anyone copy it. They're not looking for a royalty or even acknowledgment.

Q12: How can I transfer my CP/M files to DOS?

A: (Don Maslin, Will Rose, Alan Ogden, Tilmann Reh, Herb Johnson, Trevor Gowen, Hal Bower)
(Note: also see
Q13 on "disk formats".)

One solution is Sydex' excellent shareware program 22DISK which permits reading, writing, and formatting many CP/M format disks on a PC. Version 1.44 is available at:

22DISK is shareware and should be registered. It supports 8-inch drives on PC's, provided either a adaptor is wired to the PC's floppy controller or that a CompatiCard is installed. Sydex or Herb Johnson can provide assistance with using standard PC controllers. Sydex can be reached at:

P.O. Box 5700
Eugene, OR 97405
Voice: (541) 683-6033
FAX: (541) 683-1622
Data: (541) 683-1385

MicroSoulutions used to make a program called Uniform and You might be able to locate a copy at a swap meet or from a distributor. There are versions for both the IBM-pc's and a lot of different cp/m machines.

Some flavors of PC have a problem with both UniForm and 22disk and UniForm will not operate properly under DRDOS v6.0. UniForm also fails if the machine clock exceeds ~20MHz. This has been confirmed with MicroSolutions, and no fix is available.

Another solution is the MSODBALL suite of programs by John Elliot. They work by using a format (the msodball format) that is convertible via the main program to become useable on either CP/M (3.x ?) or MSDOS. MSODBALL.COM has been written in such a way that the latest version will run directly under either CP/M or MSDOS. They can be found at:

You need not use the DOS machine - there are also at least three transfer programs running under CP/M: TRANSFER (for CP/M-2.2), of which a quick-hack CP/M-3 adaptation also exists; DOSDISK, and MSDOS for CP/M-Plus written by Tilmann Reh, latest version 2.1 of Oct 93. TRANSFER and MSDOS are freely available, DOSDISK is commercial. MSDOS has two related utilities: MSFORM will create the DOS Boot Record, FAT and directory structure on a freshly formatted disk, and MSDIR will give you a quick look at the main directory of a DOS disk.

DosDisk is a standard CP/M product. As supplied, it runs only on the following specific hardware:

all Kaypros equipped with a TurboROM
all Kaypros equipped with a KayPLUS ROM and QP/M or CP/M
Xerox 820-I equipped with a Puls-2 ROM and QP/M
Ampro Little Board
SB180 and SB180FX equipped with XBIOS
Morrow MD3 and MD11
Oneac On!
Commodore C128 with CP/M-3 and 1571 drive

DosDisk also runs on any of the configurations with B/P Bios (non-banked ZSDOS only), to include the Ampro Little Board, SB-180, SB180FX, YASBEC and P112.

There is also a kit version for which the user can write his own driver, provided the BIOS implements a table-driven disk interface. Contact Jay Sage for details. DosDisk and MSDOS both handle DOS subdirectories.

You can also use a null modem or other serial link and terminal emulation programs running on each machine. For example, the CP/M machine could run KERMIT, IMP, or MEX and another program that supports the same file transfer protocol on the second machine, such as Procomm or Hyperterminal on a PC. The usual problem is getting the terminal program onto the CP/M machine - having someone send you a disk is the easiest way, but you can also use a crude assembler or basic program to transfer the real program, or use pip to send across a hex version (pip can only transfer ascii files.)

Remember, these conversion programs only move the data, as is, in its current binary form, from one disk format to another. They do not reinterpret the data so that a different program can use the information. However, there are some tools under DOS that will convert word processing file data among different word processors, such as WordStar, Word Perfect, and Microsoft Word. If the CP/M computer that made the original disk is still running, you might want to try to generate a pure text (ASCII) version of your information (e.g., by "printing to disk") before moving it over to a DOS disk. If the computer is not working but you still have the program, you might try copying it over to a DOS disk and running it under a CP/M emulator on the DOS machine to produce a text file.

Q13: How can I convert an (insert name) disk to (insert name) format?

A: (Jay Sage, Curt Schroeder, Mike Gordillo, Helmut Jungkunz, Tilmann Reh, Randy Winchester, Hal Bower, Scot Silverstein)

Elliam Associates (see above) offer disk conversion services at modest prices that can convert from just about any format to just about any other format.

If you have a Kaypro equipped with an Advent TurboROM, Plu*Perfect Systems offers a program called MULTICPY that can read/write about one hundred different 5 1/4 formats.

The simplest way of converting *CP/M formats to a PC* is to use a PC with 22DISK - just copy the files from one CP/M disk to DOS, and then back to the other CP/M disk. (See Q12.) But a few older CP/M disks have what are called "hard sectors". These disks use several physical holes in the disk to mark divisions of data, instead of ONE hole which is used as a timing reference. These disks can only be read by a PC or a CP/M system with suitable hardware. The problem is NOT the diskette drive, but the controller cabled to the drive: the drives are unmodified, it's all in the diskette controller. CP/M hard-sectored disks come from some older Vector Graphics, Heath/Zenith H89, NorthStar, IMSAI and other CP/M systems.

Similarily, it is not possible to directly read/write Apple II CP/M disks on any other host machine because an Apple disk is recorded in GCR which is incompatible with FM/MFM *floppy* disk controllers. The only way to get files out of either kind of these disks is via a serial link with the original host system, or with special hardware on the PC compatible. (See Q12.)

An example of PC hardware is a MicroSolutions device called the MatchPoint PC. When used in conjunction with a MicroSolutions CompatiCard, files can be read from an Apple CP/M disk and transfer to another disk format with a special configuration of UniForm. The CompatiCard is also able to directly read some hard-sectored disk formats.

If your are *lucky* enough to have a *CP/M* B/P BIOS, it comes with a built-in disk format emulation capability, and a library of formats, including the source so that new formats may be added.

There exists a program called "Jugg'ler" for the C128's CP/M that will read/write 140 different CP/M formats both 3.5 and 5.25 MFM (and some GCR) formats. A demo version with 22 formats, and other C128 specific CP/M software, can be found at:

The creator/owner of Jugg'ler, Herne Data Systems, is still in business, but no longer sells it. Rather, Jugg'ler's creator, Mike Garamszeghy, has graciously placed it in the public domain. Copies can be obtained from his C128-CP/M web page at:

His disk format data base and other CP/M related items are also available there.

Montezuma Micro CP/M has a "config" utility that allows logical device reassignments, setting up of comm hardware parameters, etc. Option [f] "disk drive definitions" allows the user to set the logical format of any disk drive connected to the system. There are about 100 different floppy formats provided, from A to Z. Montezuma Micro often shipped software in Kaypro format, for example. Using this redefinition utility, it is easy to read "alien" disks, format them, duplicate them to another's format via 'pip' to another drive.

The CPU280 CP/M-3 implementation offers the AutoFormat feature which allows to format, read and write almost every disk format.

Q14: Can I read my 8" disks with my PC?

A: (John Baker, Tom Sullivan)

With a program called 22disk, and an adaptor board that you can make, you can read those disks on your PC. All it takes is rearranging some of the lines on the 34 pin cable, and wiring them to the 50 pin cable, and you're in business.

The interface on 8" drives and 5 1/4" drives are essentially the same. The 34 lines on a typical 5 1/4" controller are sufficient to control most 8" disk drives using soft-sectored disks. Here, is a diagram for a basic conversion cable to allow connection of an 8" drive to an IBM-compatible, AT-style (high density) controller.

                                                      8" disk 
   PC-AT style controller                       Based on Shugart 

   Grnd. Sig.  Sig. Name                             Sig Name  Sig 
     1     2   Double/High Density ->>
                                    >>- Write Current Switch/    2    1
                                   Active Read Compensation
                                   User Customizable I/O pins    4    
                                    "         "       "    "     6    5
    33    34 **Ready ---------------<<------------ True Ready    8    7
                                    <<-------------#Two Sided   10    9
    33    34 **Disk Change ---------<<----------- Disk Change   12   11
    31    32   Side 1 Select ------->>-----------#Side Select   14   13
     3     4   In Use/Open --------->>---------------- In Use   16   15
    15    16  *Motor On ------------>>------------- Head Load   18   17
     7     8   Index ---------------<<----------------- Index   20   19
    33    34 **Ready ---------------<<----------------- Ready   22   21
                                    <<---------------##Sector   24   23
     9    10   Drive Select 0 ------>>-------- Drive Select 1   26   25
    11    12   Drive Select 1 ------>>-------- Drive Select 2   28   27
    13    14   Drive Select 2 ------>>-------- Drive Select 3   30   29
     5     6   Drive Select 3 ------>>-------- Drive Select 4   32   31
    17    18   Direction Select ---->>------ Direction Select   34   33
    19    20   Step ---------------->>------------------ Step   36   35
    21    22   Write Data ---------->>------------ Write Data   38   37
    23    24   Write Gate ---------->>------------ Write Gate   40   39
    25    26   Track 00 ------------<<-------------- Track 00   42   41
    27    28   Write Protect -------<<--------- Write Protect   44   43
    29    30   Read Data -----------<<------------- Read Data   46   45
                                    <<------##Separation Data   48   47
                                    <<-----##Separation Clock   50   49

This diagram also works in the other direction--that is, to attach high-density 5 1/4" drives to an 8" controller.


* - It seems to be a logical substitution since the vast majority of 8" drives have continuously running spindles and instead of MOTOR ON require a HEAD LOAD signal. Also, a controller sends MOTOR ON before a DRIVE SELECT.
**- Most 5 1/4" disk drives do not provide a READY signal but send a DISK CHANGE signal on line 34 of the interface. An 8" drive has provisions for both signals. Likewise, most AT-style controllers expect a DISK CHANGE signal on line 34, so lines 33 and 34 should be connected to lines 11 and 12 of the 8" disk connector. Also, some 8" drives provide a TRUE_READY signal which is more useful than the standard READY.
# - Unused on single sided drives (SA-800/801).
##- Used only on hard-sector configured drives (SA-801/851).

Some 5 1/4" disk drives have the option of providing _either_ DISK CHANGE _or_ READY on line 34 (in particular, the TEAC FD55R series). Some 8" disk controllers do not care about the DISK CHANGE signal, but must have the READY signal. If you are attaching a high-density 5 1/4" drive to an 8" controller, you may get away with making the drive always ready by shorting lines 21 and 22, but this may cause a few re-tries when switching sides. If your drive offers a READY signal that your controller can deal with, by all means use it.

The MOTOR ON/HEADLOAD dilemma may also have an alternate solution if you are connecting 5 1/4" drives to an 8" controller. Some 5 1/4" drives permit motor turn-on by means other than the MOTOR ON signal. For example, the TEAC FD55R series of drives may be configured to turn the motor on based on the state of the IN USE light. The IN USE light can, in turn, be set to turn on only on drive select. Thus selecting the drive automatically turns on the motor and neither a MOTOR ON or IN USE signal need be present.

Another way to handle 8 inch drives on a PC is with a Microsolutions Compaticard IV, if you can find one. (MicroSolutions no longer offers this product.) It has the necessary software support to properly handle 8 inch drives, and in both SSSD and DSDD. This controller can be set up as both a primary controller, or as a secondary. It can support 4 drives, of any type, including 2.8 meg. It supports two MSDOS 8 inch formats, SSSD (about 250k) and DSDD (1.2 meg). It works perfectly with 22disk, and can read and write almost any 8 inch CP/M format.

Q15: Where can I buy new diskettes?

A: (Don Maslin)

California Digital still lists hard and soft sector diskettes ­ both 10 and 16 sector at $9.95. They also stock 8" drives and diskettes.

California Digital, Inc.
17700 Figueroa Street
Gardena CA 90248
310-217-1951 Fax

One might also try:

GLOBAL Computer Supplies
2318 East Del Amo Blvd.
Dept. RA
Compton, CA 90220

Q16: Can I use the newer floppy drives on my old machine?

A: (Jeffery Jonas, Axel Berger, Dave Wilson)

You can. 3.5" and 5.25" are fully hardware compatible and your computer will never notice the difference ­ unless the 5.25 are HD drives. As 3.5" drives are able to step faster and draw less current, this direction of swapping is totally uncritical. The other way round sometimes proves more tricky.

Both 3.5" and 5.25" drives have the same 34 pin interface. 3.5" disks spin at 300 RPM thus the 250k/500k data rates. 5.25" disks spin at 300 RPM for all but the 1.2 Meg capacity, which is 360 RPM, thus the ratios:

        15 sectors per track / 18 sectors per track
                   = 300 RPM / 360 RPM
                   = 1.2 meg / 1.44 Meg
All 8" floppy disks spin at 360 RPM too.

Most old systems didn't use pin 2, 34. That's GOOD NEWS since modern 3.5" floppy drives place signals there that the old controllers can't handle. The ready/disk changed lines changed from the "XT" generation drives to the "AT" generation drives. Older floppy drives had jumpers for drive select 0-3 and where to place the status signals The "AT" floppy drives assume the "AT" signals and usually allow only setting the middle 2 drive selects, thus the cable twist nonsense. for completeness, here are the pinouts:

        Mini/Micro Floppy Interface

        Pin#  Description         Alternate Functions
        ----  -----------         -------------------
        1     GND                 Eject, Disk Change Reset
        3-33  Odd pins are GND
        2     High Density
        4     Head Load           In Use, Eject
        6     Drive Select 3
        8     Index Pulse +
        10    Drive Select 0      Motor On A    \  IBM twisted
        12    Drive Select 1      Drive Select B \ cable - both
        14    Drive Select 2      Drive Select A / drives are
        16    Motor On            Motor On B    /  strapped DS1
        18    Direction
        20    Step
        22    Write Data
        24    Write Enable
        26    Track Zero +
        28    Write Protect +
        30    Read Data +
        32    Select Head
        34    Disk Changed +      Ready +

              + signal from drive to controller

The following table is extracted from the CompatiCard manual:

           Card        34   37              50   8 Inch Drive
     Signal Name       Pin  Pin  Direction  Pin  Signal Name
     Programmable      2    3       --->    2    Low Current
     Index             8    6       <---    20   Index
     Drive Select 1/3  12   8       --->    28   Drive Select 2
     Motor Enable 1/3  16   10      --->    18   Head Load
     Step Direction    18   11      --->    34   Direction Select
     Step Pulse        20   12      --->    36   Step
     Write Data        22   13      --->    38   Write Data
     Write Enable      24   14      --->    40   Write Gate
     Track 0           26   15      <---    42   Track 0
     Write Protect     28   16      <---    44   Write Protect
     Read Data         30   17      <---    46   Read Data
     Select Head 1     32   18      --->    14   Side Select

   The odd pins of 34 pin connector to odds of 50 pin connector.
   Pins 21/37 of the DB-37 go to the odd pins on 50 pin connector.

Q17: Can I run CP/M on my MSDOS/UNIX/68K machine?

A: (Juergen Weber, Udo Munk, Paul Martin, John D. Baker, Mark Litwack, Tilmann Reh, Frank Cringle, Gottfried Ira, TJ Merritt)

Available by anonymous ftp from the primary mirror site OAK.Oakland.Edu and its mirrors:


ZSIM is an (extremely accurate) Z80 emulator (80386/40 -8 MHz Z80) in conjunction with a CP/M 80 BIOS, i.e. it simulates a Z80 machine, that can run CP/M. Together with the original CP/M operating system you have a full Z80-CP/M machine.

If you don't have a CP/M system disk at hand, you can use the included public domain CP/M compatible operating system P2DOS.

ZSIM uses CP/M format disks, a ram disk and a hard disk. Supported disk formats are CP/M 86 single sided and double sided, but you can install any singled sided CP/M format PC drives can physically read. So you can use ZSIM to transfer data to MS-Dos. The ram disk can be saved to the PC hard disk. The hard disk is in an MS-Dos file. A sample hard disk containing the SMALL-C compiler is included.

As ZSIM uses an original operating system and CP/M disks it should run every CP/M program that does not use special hardware. ZSIM is free for personal use. Sources of the CP/M BIOS are included.
On (formerly: you'll find:


(Also available as z80pack.tgz at in the directory /pub/others.)

This is a Z80 CPU emulation completely written in C, an I/O emulation for a typical CP/M system also is included. The package also comes with the BIOS source for the I/O emulation and a Z80 cross-assembler. It was developed it under COHERENT but it's known that it does work under Linux and SunOS too. You still need a CP/M license to get CP/M running or you might try to get one of the free available CP/M clones running on it. On a 486/66 DX2 running COHERENT it's like a 11Mhz Z80 CPU, so the emulation speed is acceptable.

On you'll find:


This package, written by Michael Bischoff, is well integrated into the host operating system. It provides options to use either a container file for the CP/M disk for full BIOS compatibility, or to access the Linux file system through the included BDOS emulator. The Z80 emulator is written in 86 assembler and the rest is in C. A pre-assembled ZDOS CCP is included with the package. The emulation speed on a 486/66 is approximately a 22 Mhz Z80, and on a Pentium/90 it is 50 Mhz. Full source is included.

On you'll find:


MYZ80 is a Z80/64180 emulator package. The new 80486, 80386 & 80286 machines with the fast hard drives and the snazzy OS/2 operating systems are such a delight... but for many, the Z80 machines still have to be fired up from to time in order to develop code for CP/M and the Z80 chip. Well, not any more, thanks to MYZ80.

Other emulators on the market are less than satisfactory solutions. Of the small number which can actually run without causing system errors under the later versions of DOS, apparently none is capable of running real CP/M. Instead they use an emulated version of CP/M which is only as accurate as the developers have bothered to make it.

MYZ80 can run CP/M 3.0 and ZCPR (which is such a useful Z80 developer's environment). So if you suffer from less than perfect Z80 emulation and slow overall performance, give MYZ80 a try, and save the 'real' Z80 machines for those cold winter mornings when you really need the heat. The author of MYZ80, Simon Cran, can be reached at:

Simeon Cran P/L
PO Box 5706
West End, Queensland, AUstralia 4101

(One byte is wrong in the MyZ80 CPM 2.2 bios distributed with the registered version 1.20. Subsequent releases will be fixed, but everyone who has that version will have trouble accessing the ram disk unless the C: drive is accessed first. To fix the problem change the byte at offset 16CE in MYZ80.SYS. It will be 03 but should be 04.)

22NICE is (like 22DISK) from Sydex. It emulates the application program while translating all BDOS and BIOS calls into the appropriate DOS calls. This way, it's comparably fast and allows for free use of the DOS file system (including paths). You are able to map drive/user combinations to particular paths in the DOS file system. The emulator can be configured for different emulation modes (8080, Z80, and automatic detection) and different terminal emulations. There are two run-time options: First, you can create a small COM file which will then load both the emulator and the CP/M program (contained in a .CPM file to avoid confusions); Second, you can build the emulator and the application together to a single COM file (which is larger then but needs no run-time module). You can obtain a demonstration copy from:

Yaze is another Z80 and CP/M emulator designed to run on Unix systems. It is available via ftp and www at:

The package consists of an instruction set simulator, a CP/M-2.2 bios written in C which runs on the Unix host, a monitor which loads CP/M into the simulated processor's ram and makes Unix directories or files look like CP/M disks, and a separate program (cdm) which creates and manipulates CP/M disk images for use with yaze.
Yaze emulates all documented and most undocumented Z80 instructions and flag bits. A test program is included in the package which compares machine states before and after execution of every instruction against results from a real Z80. Yaze is independent of the host machine architecture and instruction set, written in ANSI standard C, and is provided with full source code under the GNU General Public License. It supports CP/M disk geometries as images in Unix files or as read-only disks constructed on-the-fly. These disks are indistinguishable from real disks for even the most inquisitive, low-level CP/M programs and can be mounted and unmounted at will during emulation.

Please also check the CP/M 3 YAZE homepage at

There is a CP/M 2.2 Simulator that simulates an 8080 CPU and CP/M 2.2 environment. The heart of the simulator is written in 680x0 assembly language for speed. It has been tested under DNIX (a SVR2 compatible with many SVR3, BSD, Xenix, and Sun extensions), on a 68030 NeXT, and on a 68030 Amiga running SVR4. One 'benchmark' shows that on machines of the 68020/68030 class the simulator performs about as well as a 7 MHz Z-80 would. Other tests indicate that this is somewhat optimistic. The simulator was posted to alt.sources and can be found at:

in files 9954 to 9959.

Q18: Where can I get a boot disk for (insert system name)?

A: (Don Maslin, Herb Johnson)

Getting a system disk is pretty easy - if Dina-SIG CP/M System Disk Archives has it. However, some dialogue with the requester has usually been necessary to assure that we are talking about the same Jurassic inhabitant! There are just too many variants in the CP/M world. A request with specifics on the computer, an address to mail to, and some recompense is all it takes. Since this is an unfunded effort on the part of the SIG, the costs of media, mailer, and postage must be recouped. In general, and there are variations, this runs $3 for the first disk and $2 or less for each additional. Eight inch disks are a bit more! However, a swap can be arranged if the other party has disks that are not duplicative of ones already in the archive. If you can help augment the archive, yours is free.

The keeper of the archives can be reached at:

Don Maslin
7742 Via Capri
La Jolla CA 92037

Q19: What terminal emulation programs are available?

A: (Peter A. Schuman, Howard Goldstein)

The leading CP/M public domain or freeware (author kept copyright but distributed it for free) modem programs are:
MDM740 - The last of the "MDMxxx" programs.
IMP245 - This is nice, and works smoothly within what it does.
What it does, it does very well. IF you have slow floppy drives, there is a patch to cut down the receive buffer size.
MEX114 - different from the above two, but minimally functional with just a MDM740 overlay. To use all of its fine features, you need MEX overlay for your machine.
ZMP15 - This program includes ZMODEM file transfers.
KERMIT - This program may have the widest implementation base because it uses only printable characters for its file transfers. This is a plus because the MODEM7 family of protocols send binary characters that sometimes conflict with the underlying system use. It is a minus because many more characters must be sent and thus is slower. KERMIT may be found on
QTERM43F - This is somewhat like using QMODEM on an MSDOS machine. Qterm has VT100 emulation mode as well as XMODEM and KERMIT protocol. If you can get (or write) a good overlay, this is a nice program. (Bug fixes to 43E were released in a separate library to bring it up to 43F. The FIX library did not include a new binary; users had to do their own patching.)

For high speed transfers, you will probably need interrupt-driven routines, which are available for some these. The exact baud rate where it becomes necessary varies by system and program.

Q20: How do you unpack a .ARK or .ARC file?

A: (Gier Tjoerhom, Don Kirkpatrick)

Archive files are a collection of related files packed together so they stay together. They have somewhat been replaced by librarys, but are still encountered often. The C or K at the end only differentiate the original packing program, they are otherwise identical. Some archives are self extracting, just rename them with a .com ending and execute them. Others must be unpacked with a program, unarc16.ark containing one of the most popular (in a self extracting archive). This archive can be found at:

Q21: How do you unpack a .lbr file?

A: (William P. Maloney, Peter A. Schuman)

A .lbr is a single file that contains a number of compressed files inside. The files must be extracted from the .lbr before the can be used.
One very good library extract program is called It's simple to use and uncrunches the files at the same time. EXAMPLE:

A>lbrext b:myfile.lbr c:*.* uo

This takes the file on 'A' to extract all the files in myfile.lbr on 'B' and put them on 'C' uncrunched. A simple 'lbrext' first will show you how to use the .com file.

Other popular library maintenance programs are LUE, DELBR, and NULU, the latter being one of the best CP/M programs for handling LBRs. However, don't use NULU to extract and unsqueeze simultaneously. It occasionally screws up doing this, and it can trash an entire disk when it does so.

LT31 is also able to unpack libraries and also supports all current compression standards (including LZH 2.0!). It is a very useful utility and can replace several single programs.

Q22: What are all these .xQx, .xYx, and .xZx file types?

A: (Don Kirkpatrick)

These are compressed files, a.k.a. squeezed or crunched files. They must be uncompressed before they can be used. They differ in the compression algorithm; .?Q? was the first generation and .?Y? the newest. There are many fine programs that uncompress files, but most handle only one or two compression types (e.g. SQ111.ARC and CRUNCH24.LBR). One program that will uncompress all three types can be found in CRLZH20.LBR.

Q23: Are any of these .ARK, .LBR, or CRUNCH utilities on MSDOS?

A: (Geir Tjoerhom, Mike Finn)

Yes, MSDOS versions do exist and can be located as follows:
.LBR, .yQx, .xYx, .xZx:
(If the above mirror sites are unavailable, please check the Simtel archives themselves for download.)

CFX is the acronym for Cp/m File eXchange by Carson Wilson. As its name suggests, CFX is a tool intended to allow quick access to CP/M files. While CFX will operate on standard ASCII files, its main strength is its ability to access files stored with the special archiving and compression methods native to the CP/M operating system. Specifically, CFX can handle files compressed with Roger Warren's LZH utilities (.xYx), Steve Greenberg's CRUNCH utilities (.xZx), "squeezed" files (.xQx), and archives built using Gary Novosielski's Library definition (.LBR).

Q24: Why does my Kaypro drop characters above (insert baud rate)?

A: (Jeff Wieland, Stephen Griswold, Don Kirkpatrick)

The basic problem is that updating the screen takes too long and some incoming characters are missed. The exact baud rate where characters begin to disappear depends on the configuration of the Kaypro and the terminal program. Generally, the older non-graphic Kaypros will run at a much higher baud rate before characters start to disappear. Stock Kaypros are not interrupt driven and the BIOS ROM has several built-in delays, which demanded too much of a 2x/4x/10's time.

Several things can be done to help the situation. If your Kaypro came with the MITE software package, you can use it for high speed terminal emulation. A Kaypro 2X using MITE can go as fast as 19200 bps. MITE uses interrupts to achieve this.

Sometimes the problem can be ignored. A 2X will drop characters at 300 baud using Kermit-80. File transfers work fine at 19200 bps. It is always a good ides to run file transfers in the quiet mode if terminal mode is dropping characters as then the display update time is minimized.

The graphic-equipped Kaypros can be significantly improved in terminal mode just by turning off the status line at the bottom of the screen. As most terminal programs have an initialize sequence available, just send the no status line command to the Kaypro - <ESC>, C, 7 [1BH, 43H, 37H in hex].

There are several hardware changes that can lessen or eliminate the problem. There is a speed modification for the 1983 Kaypro-II's & IV's requiring changing some chips to faster versions and outfitting the back with a toggle switch. Upgrading to a MicroCornucopia MAX-8 or Advent TurboROM also helps.

If your machine is equipped with the Advent TurboROM and you choose to run QTERM, Don Kirkpatrick can send you an interrupt driver that allows the graphic-enhanced Kaypros to work just fine to at least 2400 baud.

Q25: What is the Advent TurboROM?

A: (Don Maslin)

The Advent TurboROM is a firmware upgrade to the Kaypro. It replaces the original Kaypro system ROM and provides flexible configurations, additional disk formats, greater speed, and bug fixes. Contact point for this is:

The Computer Journal
P.O. Box 3900
Citrus Heights, CA 95611-3900
Voice: (800) 424-8825 or (916) 722-4970
Fax: (916) 722-7480
Web page

Q26: How can I add a hard drive to my CP/M machine?

A: (Don Kirkpatrick, Herb Johnson)

If you have a Kaypro, TCJ - The Computer Journal can sell you a hard drive conversion kit. (See Q20.) Emerald Microware no longer offers hardware support.

Tilmann Reh, an engineer in Germany, has designed an IDE hard drive interface that plugs into a Z-80 socket, and described it in The Computer Journal magazine as the Generic IDE (GIDE). He has produced a number of kits that include the circuit board, parts, and even a time of day clock chip. Several people have bought these (as of Jan 1996) and are beginning to write software to support these on various Z-80 based computers (including ADAM and TRS-80 as well as CP/M based systems).

Europeans can contact Tilmann Reh directly. In the USA, Tilmann may refer you to a US distributor. The current US distributor is The Computer Journal which has a GIDE Web page (See Q23.)

Q27: What belongs in the unpopulated board area on a Kaypro?

A: (Don Maslin, Don Kirkpatrick, Peter A. Schuman)

A clock and modem go there. The modem is rather useless as it is only 300 baud. The clock/calendar is useful. The Computer Journal, issue 64, Nov./Dec. 1993, describes the installation procedure. There is also an area on a 2X for a hard drive interface.

Q28: What is The Computer Journal?

A: (David Baldwin)

The Computer Journal has had many articles on CP/M and Z-System and has all back issues available. TCJ also sells software that was formerly from Sage MicroSystems East and Kaypro items from Chuck Stafford.
The focus of The Computer Journal is source code and schematics for "do-it-yourself" software and hardware projects. We feature mostly low level projects in hardware, assembly language, 'C', and sometimes Forth. Our articles cover PC's, microcontrollers, and embedded and older systems.

In general, we cover software and hardware that one person can work with, where you can "do it by yourself". This includes common programming languages and boards and systems where you can identify (and get) the parts and get code to make it work. Source code from the articles is posted on the TCJ Web pages and BBS so you can download it instead of typing it in.

The subscription rate is $24 for 6 issues or $44 for 12. Subscriptions may be sent to:

The Computer Journal
P.O. Box 3900
Citrus Heights, CA 95611-3900
Voice: (800) 424-8825 or (916) 722-4970
Fax: (916) 722-7480

The The Computer Journal has it's own mailing list. To subscribe, send an email message to '' with
subscribe list-tcj <your@email.address> end

as the body of the message. 'list-tcj' is a digested mailing list - the messages are collected during the day and then sent out to subscribers in the middle of the night. That way, you only get one email message from the list on any day.

The Computer Journal (TCJ) is also on the Internet.
Web page

Q29: Are there other magazines supporting CP/M?

A: (Jay Sage)

The Z-Letter from David McGlone is no more. Classic Computing (formerly Historically Brewed), edited by David Greelish is available at:

Classic Computing Press
5227 Seaspray Ave.
Jacksonville, FL 32244

These magazines may list other publications, support groups and CP/M supporting companies.

Q30: Does anybody support Amstrad machines?

A: (Matthew Phillips, Bill Roch, Howard Fisher)

WACCI on includes:
A directory of suppliers for Amstrad CPC and PCW machines An "email helpline" of contacts who are willing to give advice A listing of other Amstrad user groups and magazines Forthcoming events in the Amstrad world The WACCI PD Library listings ­ both Amstrad and CP/M stuff.

There is also information on WACCI itself, the UK's biggest Amstrad CPC user club, including details of subscription rates.

Amstrad support is also available from Bill Roch. He offers software, hardware and does repairs on the PCW's - 8256, 8512 and 9512. He may provide the most support for the wonderful Amstrad in the U.S.

Bill Roch
4067 Arizona Avenue
Atascadero, CA 93422
(805) 466-8440 - phone
(805) 461-1666 - fax - email

The descendant of Locomotive Software, a developer of software on the PCW (and CPCs) for Amstrad, are now with LocoScript Software. Their web page is mainly concerned with proprietary word processing software, but has some CP/M related stuff and has links to other useful PCW CP/M related sites. Try:

Howard Fisher
LocoScript Software
10 Vincent Works
Dorking, Surrey H4 3HJ, UK
Tel 01306 747757
Fax 01306 885529

Q31: Does anybody support Sharp Machines?

A: (Maurice Hawes, Mike Mallett)

The SHARP USERS CLUB, based in the U.K. but with members in Europe, South Africa, and Australia. The SUC started in 1980 and its quality Magazine, published 3 times a year, covers ALL Sharp computers, including the latest PC laptops. The SUC has a large library of PD software for all the older Sharp machines such as:

Z80 machines (Sharp Basic Tape/Disk OS or CP/M programs): MZ-80K, MZ-80B, MZ-80A, MZ-700, MZ-800, MZ-3500, and PC-3201 (The PC-3201 was known as the ZY-3200 in the USA).

Also Z80 machines that were sold mainly or exclusively in Japan e.g. X1, MZ-2500.

Early 8086 machines (CP/M-86 or non-IBM Sharp MS-DOS programs): MZ-5500, MZ-5600, 'SHARPWRITER', PC-5000 'Bubble' machine.

The SUC can supply hardware upgrades and documentation for many of the above machines. Contact :

Maurice Hawes
Sharp Users Club
6 Belle Vue
The Esplanade
Dorset DT4 8DR United Kingdom
phone: +44 1305 783518

Email enquiries may be sent via

Q32: What is ZCPR and the Z System?

A: (Jay Sage, Mike Finn, Don Kirkpatrick, Dave Baldwin)

The original ZCPR was written in Z80 code and was called the "Z80 Command Processor Replacement". It was a drop-in replacement for the Digital Research CCP (Console Command Processor) and adhered to the 800H space restriction. ZCPR2 (February 14, 1983) was the first experiment in greatly extending the power of the command processor. It added additional memory modules for supporting such things as multiple commands on a line, a dynamically reconfigurable command search path, and directory names associated with drive/user areas. The ideas and implementation in ZCPR2 were only half-baked, and they came to logical fruition in ZCPR3 (Richard Conn's 3.0 and Jay Sage's 3.3 and 3.4).

ZCPR3 gives you UNIX-like flexibility. Features implemented include shells, aliases, I/O redirection, flow control, named directories, search paths, custom menus, passwords, on line help, and greater command flexibility. ZCPR3 can be found on many BBS and SIMTEL mirrors. The Z System commercial version is available for a nominal fee from The Computer Journal. Further details can be found in the text "ZCPR3, The Manual", by Richard Conn, ISBN 0-918432-59-6.

You can find a detailed history of the development of ZCPR and the Z System in Jay Sage's column in issue #54 of The Computer Journal. This article celebrated the 10th anniversary of ZCPR, which was first released on February 2, 1982. His "ZCPR33 User's Guide" also has a section on the history.

There still are active Z-nodes supporting Z-system and many RCP/M's supporting CP/M as well as some special interests. As of November 7, 1995, the known BBS's supporting the Z-System are:

    Z-Node  Sysop                 Telephone      Type of BBS
      3    Jay Sage             617 965 7046    PC    33,600 baud
      5    Ian Cottrell         613 829 2530  Z-Syst   2,400 baud
      6    Finn, Morgen, Isaac  215 535 0344  Z-Syst   2,400 baud
      9    Don Maslin           619 454 8412    PC    14,400 baud
     33    Jim Sands            405 237 9282  Z-Syst   2,400 baud
     36    Richard Mead         626 799 1632    PC    28,800 baud
     45    Richard Reid (Ken)   713 937 8886    PC      ?    baud
           Michael McCarrey     509 489 5835  Z-Syst   2,400 baud
           Wil Schuemann        702 887 0408    PC    28,800 baud
           Wil Schuemann        702 887 0507  Z-Syst   9,600 baud 
     TCJ   Dave Baldwin         916 722 5799    PC    14,400 baud
   There is also a Z-node in Munich, Germany,
     51    Helmut Jungkunz      +49.8801.2453         28,800 baud
     (also accessible via ftp at
   and one in Perth, Australia.
     62                         +61 9 450 0200

Q33: What ever happened to the Z800?

A: (Ralph Becker-Szendy, Frank Zsitvay)

The Z800 was planned to be NMOS, and was finally implemented as the Z280 in CMOS, five years late. And it does have a 4kB/8kB paged MMU, and separate I/D space, and cache. There are small differences between the Z800 preliminary spec and the final Z280 specification. The call for Z280 end-of-life last time buys went out in December, 1995.

The Z180 was not an outgrowth of the Z800. It was a joint effort between Zilog and Hitachi. The first two versions of the HD64180 were slightly different from the current Z180. The current HD64180 and Z180 are identical, and both have flags in one of the control registers to emulate the earlier versions. The changes are mostly bus timing, as the HD64180 was designed to interface with Motorola 6800 style peripherals as well as Intel and Zilog, which wasn't too strange since Hitachi second sources some Motorola 6800 series products.

Q34: What is the status of the Z380?

A: (Ralph Becker-Szendy)

The Z380 is a 32-bit version binary-compatible upgrade of the HD180. The 18MHz part in the 100-pin QFP package is shipping. The plan for a PGA-package for the Z380 has been scrapped. Zilog is working on a 25MHz part, but it isn't quite ready yet. The "Preliminary Product Specfication", Zilog part number DC6003-02, documents the part. According to the manual, the plans include a 40MHz part, but the time frame is uncertain.

Q35: What is the KC80?

A: (Ralph Becker-Szendy)

There was an announcement in the trade press about a deal between Kawasaki Heavy Industries and Zilog. Kawasaki has developed something called the KC80, which is a Z80 (no MMU, extended address space, or 32-bit enhancements), but speeded up to execute most instructions in one or two cycles, and running at 20MHz. Zilog has the rights to the design. The catch is that Zilog is currently not planning to sell it as a chip.

Q36: What is the S-100 bus (also known as IEEE-696 bus)?

A: (Herb Johnson)

Among the earliest microcomputers offered to electronic hobbyists in the mid-1970's was the Altair 8800 by MITS. It was offered as a $400 kit in an article in the January 1975 issue of Popular Electronics magazine. Each functional block of the computer, such as the processor, memory, or I/O required at that time many logic or memory chips each. So a card was designed for each function, connected together by plugging into a common bus of parallel connections or "motherboard". The function and timing of signals on the 100 pins of that bus became known as the "S-100 bus". The Altair was distinctive for its "front panel" which displayed binary address and data on LED's and which provided toggle switches to control the processor, much like minicomputers of the era.

While not the first microcomputer or microcontroller to be offered for public sale, the Altair 8800 is often cited as the "first personal computer" as it was a widely accepted and visually recognized product; it recieved a lot of press coverage inside and outside the electronics industry; and it set a manufacturing standard for a new industry. It and its successors were certainly early yet enduring leaders in affordable personal, business, and industrial computers. Only the IMSAI 8080 compares in recognition value among hobbyists, but the Altair is often cited by the popular press.

At first, MITS (and almost immediately others) produced cards which were compatible to the Altair bus. Soon, IMSAI and others followed with the production of competitive yet (somewhat) compatible systems. The S-100 bus evolved as other manufacturers, notibly IMSAI, made slight changes to the Altair bus signals and improved the front panel. Yet other manufacturers used digital designs that either depended on special signals from their own cards, or had signal timing requirements that varied between manufacturers. Over time, these differences and the limits of the original Altair/IMSAI produced a number of manufacturer-specific bus variations for extended addressing, bus operations, memory refresh and so on. MITS, IMSAI, Cromenco, Compupro, Ithica Intersystems and Northstar were among the major S-100 systems manufacturers of the time. Card manufacturers are too numerous to list. Most S-100 systems used the 8080, Z80, or 8085 processors, but some companies produced cards with almost any available 8 or 16-bit processor.

Bus signal differences were finally addressed in 1983 with the publication of the IEEE-696 standard by the Institute of Electrical and Electronic Engineers. The standard was previously in use primarily by Compupro and Ithica. As CP/M personal systems went to single-board designs with no bus at all, the introduction of new S-100 designs peaked. Further competition, price pressures, and finally the IBM PC caused new S-100 system designs for business and personal use to drop in the mid-1980's. A notible system of the era was the Heath\Zenith Z-100, a dual processor 8085/8088 system that could run CP/M 80, CP/M 86 and MS-DOS: and *very* similar to the popular Compupro 8\16 system. Zenith sold thousands of Z-100's to the military. Incidently, many systems of the mid-1980s began to run other operating systems, such as CP/M-compatible Turbodos, ZCPR and Z-system; and various UNIX-compatible OS's on 68000's, 80286's, and other processors.

New IEEE-696 systems were subsequently developed through the end of the 1980's, primarily for industrial and/or development (non-CP/M) applications, particularly where multiprocessing or speed were important. Up to at least 1993, Compupro and Cromemco still supported these systems at commercial prices, but apparently they did not support their prior CP/M systems except as cards and documentation for sale. New S-100 cards were also introduced throughout the 1980's, but declining through the end of the decade. Zenith's Z-100 system is supported by some active user groups and on-line maillists such as Usenet's comp.sys.zenith.z100. Northstar systems owners correspond occasionally on comp.sys.northstar.

One person who provides S-100 cards, documention, and some support is Herb Johnson. As "Dr. S-100" he wrote (1994-96) a regular column in The Computer Journal ( and corresponds with S-100 and IEEE-696 owners. As of 1996 he can be reached via The Computer Journal or:

Herbert R. Johnson
Dr. S-100
59 Main Blvd
Ewing NJ 08618
(609) 771-1503
Web page:

Q37: Anyone know a good source for cross assemblers?

A: (Roger Hanscom, Mike Morris)

There are a variety of sources for cross platform development tools.

The C Users' Group (1601 W. 23rd St., Suite 200, Lawrence, KS 66046-2700) has a library of software that includes all kinds of development tools. Source code is distributed with many of them. They charge $4/disk and $3.50 s&h per order, and can supply 3.5" or 5.25" DOS formats. Those of you seeking assemblers or disassemblers will be particularly interested in volumes number 398, 363 (2 disks), 348, 346 (2 disks), 338 (2 disks), 335 (4 disks), 316, 303, and 292(4 disks). They also market a CD-ROM of volumes 100 through 364 for $49.95 list (it can usually be found at computer shows for $25 to $35). They can be reached at 913/841-1631 FAX: 913/841-2624.

The Circuit Cellar BBS is on-line 24 hours per day with some cross development tools, particularly for CPU's that are commonly used as controllers. They have a Courier HST running 2400/9600 bps at 203/871-0549, and another line that will do up to 14.4k bps (8N1) at 203/871-1988. Both of these numbers are in Connecticut.

The Motorola BBS is in Austin, Texas, on 512/440-3733. They have downloadable cross development products mostly for the 68xx and 68xxx architectures. Like the Circuit Cellar BBS, this BBS seems to specialize in micro-controller development. Many of these files can also be accessed over the network on (

2500AD software lists a Z80 assembler, a Z80 C compiler (that includes the assembler in the package), a Z280 assembler, a Z280 C compiler (that includes the assembler), and a Z380 assembler.

Don't forget to look in the old familiar places, such as and

The Walnut Creek CDROM has some tools from some of the sources listed above on the CP/M CDROM.

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