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I am no longer active in this hobby for the foreseeable future. 
I will no longer maintain or update the website, but I will leave it accessible to the web for as long as possible (years).


Mark-8 Restoration
Other Mark-8's

Mark-8 Minicomputer
MOS Kim-1
Imsai 8080
TV Typewriter
The Digital Group


Mark-8 Minicomputer Documentation

I have been collecting vintage computers and books for many years now (since they were cutting edge!), these are a few that I have scanned into pdf format for posterity. Many of the files here relate to other 8008 CPU based machines such as the Scelbi 8h & 8b, Mod-8, Mike, and many others.

Most of the information here has been scanned from my own originals, some was scanned by others and sent to me. There might be a few that were pulled from other web sites, but if they are here, I have originals somewhere and was just too lazy to duplicate the work. :) Also here a few of my own software listings.

Most scans were done at 200-600 dpi, depending mainly on when they were scanned. Some of the pdfs are searchable, but most are not.

Please Be Kind...

I have limited bandwidth! Download only what you know you want or need, and take your time--only download what you need right now, then save what you download so you need not download it again. Thanks, and enjoy!

m8docs.jpg (180458 bytes)
Pile O' Mark-8 Docs

Mark 8 construction article:

I have three original copies of the Mark-8 construction booklet, as well as a photocopied one from Jon Titus. These were among the first things I ever tried to scan and convert to pdf, I must have scanned these about a dozen times trying to get the best printable and readable copy.

RE_Mark-8_Construction.pdf - 21.8 Meg My scans of the article from a photo copy sent to me by Jon Titus. This is a very useful scan as it contains a hand drawn backplane diagram from Jon Titus, not included in the original article. Don't try to make boards from these scans!
RE_Mark-8_Const-NEW.pdf - 39.6 Meg These are NEW scans, 4/07, from my best copy of the construction article, scanned at the highest dpi my scanner can do, and BONUS - These scans are searchable! Not a perfect OCR, but better than a finger in the eye, huh? Also, my scanner did an auto-rotate on a few of the pages... deal with it.
Mark_8_connection_info.pdf - 12 KB Front panel switch wiring chart, circuit board top connections, and the layout I used to restore my front panel. Info that was missing, or just plain hard to figure from the original plans.
Bugs.pdf - 68 KB This is a list of known Mark-8 bugs, taken from a page of the Micro-8 Newsletter.
Sigs.pdf - 172 KB Pin outs of Signetics chips used in the Mark-8

Construction details of my 4K Memory Board, with photos and schematics:

My_4K_Memory.pdf - 1.9 Meg My board is most likely a Celetron board from Maury Goldberg of MiniMicroMart. Celetron used the "CF2" logo on their boards, and the blue material as well. Godbout seems to have bought or borrowed the design.  (Godbout info from Jim Kearney. Thanks Jim!)
32KMemory.pdf - 41 KB in 2006 I added 32K of bank-switched RAM to my Mark-8.

Intel Manuals

8008UsersMan_Jun72.pdf - 22.2 Meg This is my earliest 8008 manual, which was given to me by Jon Titus, very good info.
8008UsersMan_Nov72.pdf - 6.0 Meg Some minor changes, check it out.
8008usersManualRev4_Nov73.pdf 12.4 Meg Yet another Version
Intellec8_RefManual_Jun74.pdf - 10.6 Meg Manual for the Intel Intellec8 Computer!!
intellecMDS_schematic.pdf - 5.4 Meg Good stuff...
Intel_MSC-8_April_1975.pdf - 26.2 Meg More good stuff!!
MCS-8_PLMprogGuide1973.pdf - 4.3 Meg From the net. Any PLM programmers out there?

The Digital Group

The Digital Group was a pre-Altair era company that made accessories for the Mark-8. This Packet of information showed M8 users how to expand their I/O ports, add a cassette interface and a video card to their systems. It also includes listings for all the software needed to operate these new additions... Really cool! Read about the digital group by clicking the above link.

dg_packet.pdf - 2.4 Meg The original "Packet #1", These scans are from my original copy, given to me by the author, Dr. Robert Suding.
M6570.pdf - 6.0 Meg Data sheet for the character generator chip used in the DG TV Typewriter. Hard to find item.

Microsystems International

This was a Canadian company that second sourced the 8008, they went belly up not too long after releasing this applications manual. This manual has information on the Mod-8 too.

Applications_Manual.pdf - 25.3 Meg Excellent information, construction information for the MOD-8, great operating system software that even includes a simple assembler/diassembler!
gnc8.pdf - 6.1 Meg I think this version was distributed in Canada
mf8008.pdf 6.7 Meg Yet another version. I have not inspected these versions for differences... they may all be the same inside.


The Mark-8 spawned at least two newsletters, and they contained a wealth of information. The "Micro-8 (aka, Mark-8) Newsletter" was mostly a collection of letters from 8008 based machine builders. There is a bundle of troubleshooting hints and bug reports for the Mark-8 in here! It also carried some articles for the then new 8080 and Altair, but the focus was the 8008. "The Computer Hobbyist" was more professional and contained nicely written articles of amazing nature, intended for the 8008. Most of these scans were done by Jim Kearney, I cleaned them up a bit and made pdf files out of them. Although I have my own originals (seen in the photo), his  scans were already done. Why re-invent the wheel? 

The "ECS Magazine" was a very professional mini-magazine devoted mostly to the 8008. ECS was edited by Carl Helmers, who was pulled from the newsletter by Wayne Green to become the founding editor of the then new Byte Magazine. Five issues are included here. (Also shown in the photo here, but not here, are a couple issues of the "digital group Clearinghouse". This was Dick Bemis' entry into newsletters, and was pretty much a flop.)

My Newsletters


These two files comprise the first two years of the Micro-8 newsletter.

Micro-8_Vol-1_all_issues.PDF - 39.7 Meg The first few pages look terrible, but they actually look better here than in the original newsletter!
Micro-8_Vol-2_all_issues.PDF  - 18.1 Meg The Micro-8 was probably the most useful of the newsletters available on the 8008.

The Computer Hobbyist

Flyer.pdf 2.1 Meg Flyer, advertising the new newsletter.
TheComputerHobbyist_all_issues.PDF 23.8 Meg Well, maybe not ALL issues(?) but all the ones that I have anyway.

ECS Magazine

ECS_Vol1_1-5.PDF - 10.3 Meg Five issues from 1975. From historical data on the origins of Byte Magazine, I believe this is a complete collection for that year. There was at least one earlier year, which I do not have. ...do you? :)

Scelbi Computer Consulting

Scelbi was on of the earliest of all computer publishing companies focusing on microprocessors. For a short time, they also made an 8008 based machine, the Scelbi 8b & 8h. Other than Intel, the first micros made in the USA.

SCELBI-8H_UsersManual_1974.pdf - 7.4 Meg This is the operating manual for the famous SCELBI 8H.
- 15.1 Meg Great for learning how the 8008 can be put to work!
Machine Language Programming 8008 - 16.2 Meg This is my 8008 Bible for writing software, all the instructions, how they work, flags they alter, etc..
Machine Language Programming 8008 - 43.7 Meg Newer version--I don't know if there are any differences.
First_Book_of_Games.pdf - 6.6 Meg Space Capture, Hexpawn, and Hangman for the 8008/8080
    Space Capture Board.pdf - 7 KB Game play board for Space Capture
- 23.1 Meg Star Trek for the 8008/8080!
Scelbal - 39.2 Meg BASIC on your 8008! (or 8080) (Scans by Kinko's).
   Scelbal_pg_12-80.PDF - 261 KB Rescan of garbled page, page 12-80
   ScelbalUpdate.pdf - 677 KB All the add-ons and corrections. Scans from Jack Rubin.
   Strings.pdf 2.2 Meg String handling for SCELBAL, these scans were done by Len Bayles, a little grainy but readable.
   Math.pdf - 1.1 Meg Math functions for SCELBAL, also done by Len Bayles, also a little grainy but readable.

My Mark-8 Software

These are a few things I put together to help me program, and a few of my programs. Careful: They may not be bug free! I have a bad habit of not documenting all my bug fixes. I usually end up fixing the same problem a couple times before getting smart enough to write it all down, if only I could learn...! Most of my software is hand written, so until I get the gumption to type it into a word processor, it will never show up here! Sorry!

All of the following files are very small - Less than 20 KB.

8008_InstructionSet_CodeSort.PDF  Yes, I know. Some of the descriptions are not 100% accurate. I was learning by trial and error, but to the best of my knowledge, the code and mnemonics are correct. Just some of the descriptions are off. (See self deprecating comment above!)
8008_InstructionSet_FunctionSort.PDF  Ditto, sorted by function.
8008_InstructionSet_MnemonicSort.PDF Ditto again, sorted by mnemonics.
Handy little instruction set reference card. I have redone this from a drawing in the Micro-8 Newsletter.
This routine saves/restores registers (except D & E, which are lost).

Scratch.PDF This very short subroutine clears memory until an error is found. Could be used to determine memory size by looking at H&L on return.
This is my M8 binary paper tape and I/O software for my ASR-33. (The comment about adding/stripping parity will not work for punching binary tapes - Don't use it!)
This is my text output/printing routine, read the comments to see how it works.
PrettyLightShow.PDF This is my "on-display" software. Unless I am working on my M8, this is what is running. Also includes a routine for random display on my Digital Group TVT. This program requires a very simple hardware mod to allow front panel switch mapping to an input port to work as written, if you don't have the mod, just load any number instead of reading the front panel data.

2003-10_vcf_sf0053.jpg (118526 bytes)

Don Lancasters TV Typewriter

TV_Typewriter.pdf - 12.3 Meg Original RE plans. These scans are from photocopies, it was all I had at the time.


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Copyright 2008 Bryan's Old Computers
Last modified:
October 16, 2009