A08 8008 (1972) cross-assembler

A08 8008 (1972) cross-assembler

Last updated Oct 1 2019. Edited by Herb Johnson, (c) Herb Johnson, except for content written by others. Contact Herb at www.retrotechnology.com, an email address is on that page..


This Web page is about a 2014 adaptation of the A85 cross-assembler to support 8008 assembly for various of my vintage computing projects.This version, A08, supports the 1972 8008 original mnemonics. On this Web domain retrotechnology.com, I restore and document many vintage computers of the 1970's. Details of A08 is below.- Herb

A08 history

I acquired an 8008 computer in 2013. I'm continuing to work on it. But I knew I wanted an 8008 crossassembler, with sources I could modify to suit various situations. One cross assembler for many processors is ASMX version 2.0, which provides sources. another is the A85, A68, A18 series of cross assemblers by William Colley. See my A18 Web page for details and discussion.

But I knew I could modify A85 to support the 8008. But there's a problem. When Intel produced the 8008 in 1972, they introduced a particular set of mnemonics or instructions. But when Intel produced the 8080 in 1975, they re-worked the 8008 mnemonics to look more like their 8080 mnemonics. Some 8008 code survives in the earlier syntax; some in the later syntax.

This version, A08, supports the 1972 8008 original mnemonics. For the 1975 8008 mnemonics, see my A8008 page for my A8008 assembler. For the 1972 8008 mnemonics, I have ANOTHER assembler which produces 8080 opcodes. see my A08_80 page for that 8008 to 8080 assembler.

All versions assume an OCTAL radix or base, and permit specifying values in decimal, binary and hex. Both provide options to support (or not) "split octal", Under split-octal, values like "123321" are treated as two bytes, "123" octal and "321" octal. A numeric value 123#321 is always treated as "split".

The program runs under Windows (XP, 2000) as an MS-DOS 32-bit executable, which runs under the "DOS box" commmand line. I provide the C sources with my changes clearly marked. There are docs and sample assembly code. For those who download it, please advise me of any errors and issues. I make zero guarantees, offer zero warrenties. I am not responsible for any loss, injury or damage to person or property of any sort. Use entirely at your own risk.

The A18 1802 cross assembler Web page also points to other Web pages, where I have other cross assemblers from Colley which I've adapted. That page has some software tools also: look there for details.

Oct 2019: Craig Andrews pointed out, I didn't implement the OR mnemonics correctly. I've fixed that. And, to check the assembler in the future, I've included an assembly program with all the mnemonics. - Herb

future: I will make small changes to the source, to compile under Borland's MS-DOS based Turbo C. When I do, both a Win32 executable and the MS-DOS executable will be included in the Zipped package. - Herb Johnson

- Herb Johnson

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

This page and edited content is copyright Herb Johnson (c) 2020. Copyright of other contents beyond brief quotes, is held by those authors. Contact Herb at www.retrotechnology.com, an email address is available on that page..