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KayPLUS was the final chapter on MICROCode Consulting monitor ROM and BIOS upgrades.  A complete replacement for Kaypro 2, 4 and 10 computers, this ROM incorporated our massive experience in upgrading Xerox and BigBoard computers and has everything one would want in a ROM and BIOS.  This was by far our most popular ROM upgrade due to its high value and versatility.  Just check out the comparison table in the next section.  Written in Z-80 assembler for use under QP/M, CP/M 2.x and compatibles, features of KayPLUS include: 

Comparison to Other Kaypro ROMs

In the table below: Of course, the Value section is meaningless as KayPLUS is now free!
Feature Kaypro MicroC Turbo Kplus
Floppy Disk Support
All Kaypro formats no yes yes YES!
3.5" drive support no no no YES!
Automatic detection of quad drives w/o hardware no yes no YES!
Unlimited number of other drive formats through included utility no2 no no2 YES!
Individual adjustable step rates no yes3 yes YES!
FAST stepping rates (2mS-5mS) no no no YES!
Drive reassignment (logical-to-physical translation) no no yes YES!
Allows you to boot from any drive no no no YES!
Hard Drive Support
Support up to two hard drives of 64Meg each no4 no4 no5 YES!
Boot from hard drive n/a n/a yes YES!
Variable partition size n/a n/a no YES!
NO editing or assembly to install software n/a n/a no YES!
FAST hard drive backup utility n/a n/a no YES!
Non-destructive hard drive test program n/a n/a yes6 YES!
ALL hard drive software included in ROM n/a n/a no6 YES!
Monitor Operation
Monitor operation no yes no YES!
Dumb terminal mode no no no YES!
Printer Support
Serial with no- or CTS-protocol; also parallel printer yes yes yes YES!
Serial data port printer no no no YES!
Serial printer using XON/XOFF or ETX/ACK protocol no no no YES!
Keyboard and Video
Adjustable screen blanking no no no7 YES!
Support of alternate character set no no yes YES!
Status line indicators for pause & screen dump no no no YES!
32-keystroke input type-ahead buffer no no yes YES!
Support for up to 8 chars per keystroke on numeric keypad and arrow keys no no no8 YES!
Enable/disable key click yes9 no no YES!
Real-Time Clock Support
ROM clock (no hardware required) no no no YES!
Kaypro Hardware Clock no10 yes yes YES!
Other: Advent, Ztime, Legacy no11 no11 no YES!
Automatic disk relogging no12 no no YES!
Built-in time/date vector no no no YES!
Special Features
Dynamic program pause no no no YES!
Advent and Co-Power 88 RAM card support no no no YES!
Extended I/O byte no no no YES!
Value (in 1986)
Basic ROM package (with included software and doc) n/a $79 $80 $70
Disk formatting software (like Uniform) $65 $60 included included
Hard drive support software (like Winchester Connection) $60 $60 included included
Hard drive formatter (like Turbo Formatter) n/a n/a $30 included
Multi-keystroke translation (like XTRA key) $29 $29 $29 included
Total ownership cost $154 $243 $139 $70
1Only Xerox single-sided/single-density resident
2Fixed number of formats; cannot add your own
3Only 2 step rates available
4Hard drives up to 64Meg supported by MICROCode's Winchester Connection
5Hard drives supported up to 56Meg
6Requires Turbo Formatter from Advent
7Screen blanking available, but not adjustable
8Only ONE keystroke supported
9Can turn off keyboard click (sometimes) with external program
10Internal real time clocks supported only with external programs
11Hardware real time clocks supported by external programs
12The original ROM will not even relog its own format correctly some of the time


Package Version Date Size (bytes) Download time
(28.8K baud)
Click to
KayPLUS '83 ROM 0.2a Sep 1986 8192 2sec kplus83.rom
KayPLUS '84 ROM 0.2a Sep 1986 8192 2sec kplus84.rom
KayPLUS software 0.2 Sep 1986 170k 1min 3sec kayplus.lbr
KayPLUS documentation 0.2 Jan 2006 449k 2min 25sec kayplus.pdf
KayPLUS software and documentation 0.2 Jan 2006 413k 2min 31sec kayplus.zip


  1. Identify your system: Kaypro 10-83, Kaypro 2-84, Kaypro 4-84 or Kaypro 10-84.
  2. Download the appropriate model year ROM image.
  3. Burn the ROM image onto one 2764 EPROM.
  4. Follow the Installation instructions within the KayPLUS documentation as the specific steps depend upon the Kaypro model you are upgrading.

This is restricted for personal use software that is provided without any warranty whatsoever as described in the legacy Z-80 home page.