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Micro Cornucopia

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Last revision of this page: May 28, 2025

MICRO CORNUCOPIA [about themselves] is the single board systems journal supporting systems programming languages and single board systems including the Big Board, Big Board II, Xerox 820, Kaypro and Slicer.

If you want to learn more about the CP/M Kaypro computers, then you definitely have to read this journal. This magazine is full of information - hence the name: CORNUCOPIA.

Through the Ages (1981 - 1990)
ROMs
- Monitor
- Character
Theory of Operation
Add-Ons
Downloads
Information
References

Through the Ages (1981 - 1990)

The first issues (1981 to 1982) focus on the Big Board, among other things. However, this changes with the appearance of the Kaypro.

Dear Editor, I would like to express my discouragement at the small number of articles relating to the BB-II. I see the emphasis shifting from BB-I to Kaypro (just look at the user disks released since BB-II came on line). I like your magazine and look forward to its arrival. Unfortunately, my expectations are dashed when I look at the table of contents. Little, very little on BB-II. Any encouraging words for the future?
A letter to the editor from issue 19, August 1984.

The Kaypro is mentioned for the first time in issue 9 of December 1982. From February 1983 to November 1988, the column The Kaypro appears. In the issue 29 from April 1986 it says among other things: Kaypro Bids Farewell To CP/M (Almost).

Actually, the new royal couple had already been called IBM and DOS since 1984/85. The old king CP/M had only not yet wanted to accept. If you don't move with the times, you move with the times.

And so it happened after nine years and 53 issues with the magazine Micro Cornucopia in May 1990.

The Last Hoorah

I'm [David J. Thompson] not sure how to begin. I've started this editorial so many times, in my daydreams, in my sleep, in the shower ... But nothing I've come up with really feels like I feel. I'm closing down Mirco C and I don't know what I'll be doing next. (Wait till mom reads this ... "Dad! Our little David's quitting his job, Quick, clean up the spare room.") [1]

SOG - Semi-Official Get-together

ROM

There are two ROMs in each Kaypro, a monitor ROM and a character ROM. The Monitor ROM supplies information for the Z80 processor on such things as how to get information from the disk drives, and which character to use as a cursor. The character ROM works entirely in the video circuit and it determines what the characters look like on the screen (for instance, does the "f" have a high, small cross bar, or a lower, longer one of the Micro C character ROM). When you speed up your Kaypro, you are speeding up the processor clock so you have to use a monitor ROM that will also run at the higher speed. You are not changing the video clock when you speed up the Kaypro so you don't need to change the character ROM (unless you want the nicer looking character set). Since the monitor ROM tells the processor how to do disk accesses you are going to have to change that ROM in order to upgrade to larger drives. [2]

Monitor ROM

According to my information the Micro C ROMs can NOT be used in the Kaypro 10 (neither '83 nor '84)! If I am wrong, please mail me.

For '83 Kaypros

The first ROM generation (2KB, 4KB) from Micro Cornucopia was intended for the so-called '83 Kaypros. The Kaypro II and the Kaypro 4.

Pro-Monitor II for Kaypro II
This ROM allows you to run 4 or 5 MHz with your Kaypro II. It does faster disk accesses.
Pro-Monitor II for Kaypro 4
This ROM allows you to run 4 or 5 MHz with your Kaypro 4. It does faster disk accesses.
Pro-Monitor 8 for Kaypro 4
This ROM allows you run to 4 or 5 MHz with your Kaypro 4. It does faster disk accesses and you get 784K per disk with quad density (96 tpi, double sided) drives. You can use any combination of single-sided (191K), double-sided (390K) or quad-density (784K) drives as drives A and B (or A, B, C and D with the (+) version). There are versions 1, 2 and 3.
Pro-Monitor 8 for Kaypro 4 (8" interface)

This ROM is fully equivalent to the previously mentioned Pro-8 (v3+), but can also address two external 8 inch drives. This ROM is required for the 8 inch adapter board.

According to Micro Cornucopia, the PLUS (+) version of the PRO-8 ROM is a further development. The PRO-8 version could only address two drives, whereas the PRO-8+ version could address four. I have the PRO-8+ version! [9]

The ROMs that support four drives have +'s around the ROM sign-on message (so we call them PRO-8+ ROMs). [9]

I use on my modified Kaypro II (=> K4 mod) the Pro-Monitor 8 (PRO-8+ V3.3) with a SGS M2732A, 4KB, 200ns EPROM.

Please remember, if you have a "fast" Kaypro II with 4 or 5 MHz, the EPROM of the Monitor ROM must be a fast one; at least 350 ns. Do not use an EPROM with 450 ns! The same applies to the CHARACTER ROM. RAM and ROM must fit together!

For '84 Kaypros

The second ROM generation (8KB) from Micro Cornucopia was intended for the so-called '84 Kaypros. Basically the Kaypro 2/84 and the Kaypro 4/84 or others with the UNIVERSAL board; but not 10 ('84) and 4X, 12X, Robie with the Drivetec drives.

Pro-884 Monitor
Pro-884 MAX Monitor

minus version
normal version

According to Micro-C both 884 ROMs do NOT run with CP/M 2.2U. You will need the F or G version. I run my Kaypro Robie with the Pro-884 Monitor (84-52), an 784K Panasonic JU-475-5, a Gotek and CP/M 2.2G.

I do not know the differences (in detail) between normal/high MAX and minus/low MAX versions. I use a D600 (minus/low) CP/M 2.2G version. If you are not sure just use CP/M 2.2F.

Details about Drives

Of course, when we made the change, we wanted to be able to continue to read and write disks for the 2 and the 4 which means when 48 tpi disks are used in 96 tpi drives the drive must step twice when it moves from one track to the next. We took care of this in the monitor.
In fact, our Pro 8 package will read, write, and format Kaypro II, 4, and 8 disks. Once the disk is formatted, the Pro-8 system looks at the disk (in either drive) and then automatically knows how to read or write that disk. The only thing you have to do is remember to warm boot when changing disk types. (You should warm boot when changing disks anyway.) [8]

The problem of writing a 48 tpi floppy in a 96 tpi drive is also described in detail in Micro Cornucopia, issue 15. [8]

Character ROM

Kaypro II & 4

The following two quotes are from David J. Thompson and come from the magazine Micro Cornucopia. They show that Kaypro has cheated here too, as with the 81-110-A (vs. BigBoard I). The first character ROM was probably originally created by David. Well, that's all water under the bridge today.

... Someday I [David J. Thompson] will tell you the history of the Kaypro character set and how I created those original characters one afternoon at Tektronix. I wouldn't admit it now, of course. ... [5]

Then one day a friend suggested I take a look at the Kaypro. Well, looking at the Kaypro screen was like homecoming. There were my ugly g, y, q, f, t ... There was no doubt about it. I knew that within that Kaypro there lay a heart of BB I and inside the character ROM were the remnants of an afternoon at Tek[tronix].

So I combined my new character set with the Kaypro Greek characters and produced the Greek PRO-CHARACTER ROM. I also left out the special characters altogether and called it the Clean PRO-CHARACTER. The Clean character set was for those who were being driven to distraction by the funny little greek characters (mostly folks into data communications with mainframes.)

I sent a copy of my character ROM to Non Linear (after getting a non-copying agreement from David Kay). They have upgraded their characters somewhat since receiving mine but they haven't gone all the way with it. [4]

The [Micro-C] character ROM gives you a nicer looking character set. Kaypros have come with two different character ROMs, the early character ROMs [81-146] had a rotten g, y, q, f, and t as well as commas and semi-colons that were hard to tell from periods and colons. On the newer systems (manufactured since Sept 83) half of the characters (notably the g) have been improved [81-146A], but they haven't gone all the way. Also, many of the older character ROMs were poor quality parts so they generated "snow" as information scrolled up the screen. This white lecky snow disappears when you install a Pro-Character ROM. [2]

I can confirm the facts about the snow. I reassembled my Kaypro II (#4,037) today with the original ROM (81-149) and CHARACTER ROM (81-146). When scrolling, this snow does indeed occur. Both ROM's still have the original yellowed paper sticker.

Below is a comparison of the letter g between the three CHARACTER ROMs possible on the Kaypro II or 4. The difference between the early 81-146 and the new PRO-8 is clearly visible.


81-146  81-146A PRO-8

-----   -----   -----
-----   -----   -----
-----   -000-   -0000
-0000   0---0   0---0
0---0   0---0   0---0
-0000   -0000   -0000
----0   ----0   ----0
-000-   -000-   -000-

Have you ever wondered how to get the small Greek letters on the screen? Then type the key sequence ESC G (or g) on the keyboard and then enter lower case letters. And look ... To go back to normal characters just press ESC A (or a).


A little ROM math:

The Kaypro II CHARACTER ROM is a 2716.
16 Kbit / 8 bit/Byte = 2 KByte (KB)

The 1st half of the ROM is empty.
Only 1 KB is used: 0400h - 07FFh.

1 CHAR = 8 Byte
1 KB = 1,024 KByte = 128 CHAR

128 CHAR => 16 x 8 matrix => see above

If you want to have a detailed knowledge about the internal coding of the CHARACTER ROM, please have a look at this text file [3]. If you want to create your own character set, read issue 6 of Micro Cornucopia, June 1982.

Here you will find a tiny 'C' program to read in the 2K CHAR ROM of a Kaypro II and output it as a readable text file. With the help of the Unix program DIFF you can quickly compare two files for differences.

"Printing" the Character ROM in a text file

You can also import the text files into a spreadsheet and display and compare the different character sets.

You want to burn a 2716 EPROM, but you only have a 2732? Very simple, just double the 2 KB image to 4 KB. That's it.

Please remember, if you have a fast Kaypro II with 4 or 5 MHz, the EPROM of the CHARACTER ROM must also be a fast one; at least 350 ns. Do not use an EPROM with 450 ns! The same applies to the MONITOR ROM.

Software

Besides the monitor ROM, however, you also need an advanced copying or formatting program for double-sided (390K) and quad-density (784K) floppy disks. The normal COPY program can only copy or format single-sided (191K) floppy disks.

I currently have the following three versions available. Ultimately, all three do the same thing, with versions 2.3 and 7.0 rechecking all tracks after the formatting process. Version 7.0 is the fastest.

Disk Utility for Five Inch Drives Version 1.5
Copyright (c) 1985 Micro Cornucopia

Diskette Format Program for the Pro8+ System V. 2.3

Diskette Format Program for the Pro8+ System V. 7.0

In combination with the Plus-4 Decoder Board, all three programs can access drives A, B, C and D and format the following three disk formats.

Kaypro 2 Format (191K)
Kaypro 4 Format (390K; destination drive must be double-sided)
Kaypro 8 Format (784K; destination drive must be quad-density)

Theory of Operation - Schematics

Another cornucopia of information can be found in the Theory of Operation and the associated Schematic. For downloads see below.

Kaypro II/4

Theory of Operation (Dana Cotant)
Schematic (Frank Guthrie)

Kaypro 10 ('83) [6]

Theory of Operation (Eric Roby)
Schematic (Eric Roby)

Kaypro 84 - by Eric Roby

Universal board (2-84, 4-84)

Theory of Operation (Eric Roby)
Schematic (S. Thompson)

Universal board (2-84, 4-84, 10 ('84)) [6], [7]

3.B is a revised and supplemented version of 3.A.

The Micro Cornucopia Schematics — Micro-C - CP/M Kaypro Schematics [7]

Add-Ons

Besides the excellent ROMs, the Micro Cornucopia team has also developed two add-ons:

Plus-4 Decoder Board. Using four floppy disk drives.
Eight Inch Adapter Board. Using up to two 8" floppy disk drives as C: and D:.

Downloads

Software

(Three) PRO-8 copy/format programs

ROM's

CHAR GREEK - 2716, 2K
CHAR CLEAN - 2716, 2K
PRO-8+ v3.3 - 2732, 4K
8" Pre-84 v3.3 - 2732, 4K (8" interface) [11]
PRO-8 r5 - 2764, 8K
PRO-884 - 2764, 8K
PRO-884 MAX, v1.0 - 2764, 8K [10]
SuperMAX, v2.7 - 2764, 8K

CHAR GREEK

CHAR CLEAN

The following ROM probably comes from David Thompson himself and was made available to Ezra Shapiro. This and the monitor ROM come from an early Kaypro II (#003-249) which, according to its current owner, probably belonged to Ezra Shapiro.

PRO-8+ v3.3

8" Pre-84 v3.3

And here something very spcial and rare. You need this ROM for the Micro Cornucopia 8" adapter board. This ROM is almost identical to the PRO-8+ ROM v3.3, but can additionally handle two external 8" drives (as drive C and D).

Micro Cornucopia - 8" Interface Kaypro Pre-84 v3 [11]

PRO-8 r5

PRO-884 MAX, v1.0

Information

ROMs & Add-Ons

The ROMs and Adapter Boards from Micro Cornucopia. A detailed description.

Manuals

PRO-8 Instruction Manual (v1), 1984 (55 MByte) [12]
PRO-8 Instruction Manual (v2), 1985 (69 MByte) [12]

Theory of Operation

Kaypro II/4 by Dana Cotant
Kaypro 10 ('83) by Eric Roby [13]
Kaypro 84 by Eric Roby
Kaypro 84 Schematic drawn by S. Thompson

Magazine

References

(↑) Micro Cornucopia, #52, May 1990, page 4
(↑) Micro Cornucopia, #16, February 1984, page 38
(↑) Vintage Computer Federation Forums, member: ldkraemer
(↑) Micro Cornucopia, #15, December 1983, page 42
(↑) Micro Cornucopia #14, October 1983, page 2
(↑) Micro Cornucopia #19, August 1984, page 20
(↑) Micro Cornucopia #49, Sep/Oct 1989, page 48
(↑) Micro Cornucopia, #15, December 1983, page 15
(↑) Micro Cornucopia, #17, April 1984, page 19
(↑) Jim Rayburn, Facebook, Kaypro Users Group, 2022
(↑) Ron Maxwell, Facebook, Kaypro Users Group, 2022
(↑) ldkraemer from Vintage Computer Federation (VCF)
(↑) shirsch from Vintage Computer Federation (VCF)
(↑) eBay sales picture
(↑) David Grimshaw, Facebook, Kaypro Users Group, 2022

My Series About the KAYPRO

--> Go to Part 0 : Information
--> Go to Part 1 : Versions
--> Go to Part 2 : Hardware
--> Go to Part 3 : 8K EPROM Modification
--> Go to Part 4 : Formatting a Hard Disk
--> Go to Part 5 : USER areas
--> Go to Part 6 : MASMENU - Master Menu
--> Go to Part 7 : Terminal
--> Go to Part 8 : KayPLUS ROM
--> Go to Part 9 : Advent TurboROM
--> Go to Part 10: Multicopy Plu*Perfect
--> Go to Part 11: The Kay Family & Company
--> Go to Part 12: Kaypro Design Views
--> Go to Part 13: Micro Cornucopia
--> Go to Part 14: Repairing a Kaypro II
--> Go to Part 15: Kaypro Collections
--> Go to Part 16: Kaypro General
--> Go to Part 17: Kaypro Robie
--> Go to Part 18: MFM-Emulators
--> Go to Part 19: Roadrunner ROM
--> Go to Part 20: Software
--> Go to Part 21: FAQ
--> Go to Part 22: Kaypro Virtual
--> Go to Part 23: Formatting a Floppy Disk
--> Go to Part 24: ROM, EPROM
--> Go to Part 25: Kaycomp