ROM monitor code - prelim

This Web page provides a number of ROM monitor sources on my site. I'm providing these 1) to support assembly language on classic 8-bit microproessors and vintage microcomputers and 2) for specific support of a brand and model of vintage microcomputer. This Web page last updated May 4 2014. (c) Copyright Herb Johnson 2014 except for content owned by others.

This is part of a number of repair and restoration Web pages I have which on this Web site; and also S-100 support and documentation Web pages. My home page points to many more vintage computing support pages. - Herb Johnson

Z80 and 8080 processor ROM monitors

Check my S-100 home page for links to specific brand Web pages for their S-100 cards. I have manuals and documents which may include source listings for specific ROM monitors associated with specific brand and model of S-100 cards.

Technical Design Labs AKA TDL AKA CDL...Apple and Zapple, 8080 and Z80 ROM monitors.

IMS 5000 system work by Richard Thwaites. He developed a ROM monitor based on several others including Zapple, DRI's DDT.COM, and more resources.

This Web page of SD Systems code for Versafloppy II floppy controllers, includes some SD Systems sources in this ZIP file including BIOS ROMs

Work by Andrew Lynch on Vector Graphic systems which include ROM images, no source.

Greg "Peter" Peterson's work on Digital Group disassembly/reassembly which includes both a dg EROM listing and a HEXMON Z80 listing from '8080 / Z80 assembly language, Techniques for improved programming' by Alan R. Miller.

Bill Beech has done extensive work to restore Intel 8080 and X86 Multibus boards to operation. That includes some ROM monitor work. Bill hosts his work on his Web site.

Thanks to OCR work from April 2014, Here's a Solid State Music ROM Z80 monitor Ver 1.1 source and also here's a Solid State Music ROM 8080 monitor Ver 1.0 source

HEre's the Z80 ROM monitor hex dump, for the Morrow MPZ80 S-100 card. More information is on my Morrow S-100 Web page in the section on the MPZ80

ROM dumps of Z80 or 8080 loaders, monitors

This linked Web page is a collection of ROM and PAL images for various S-100 systems. They include Compupro, Cromemco, Heath, MOrrow, NOrthstar, Teletek.

Among my Northstar Horizon Web page, there's ROM disassemblies for the Northstar boot ROM from several people.

On my digital group Web page, there's a section on "DG ROMs I (may) have". These are hand-disassembled from dg listings of ROMS, which are essentially loaders for dg cassettes or diskettes.

My Web page on Ithaca Intersystems DPS-1 includes extensive discussion of the boot process from ROM to diskette. Here's a listing of the DPS-1 boot ROM.

COSMAC 1802 processor ROM monitors

Lee Hart's COSMAC 1802 Idiot ROM monitor. This can run entirely in ROM, no RAM needed.

Intel 4004, 4040 ROM monitors

I have an Intel MCS Intellec 4/40 system. In work with Kyle Owen, we compared ROM sets and I was able to replace one of his "dead" ROMS so he could restore his system to operation. Look at that work, and see the ROM dumps and simple disassemblies of 4040 code. This work is rarely done today.

Contact information:
Herb Johnson
New Jersey, USA
To email @ me, see
see my ordering & contact Web page.

Copyright © 2014 Herb Johnson