Digital Sandbox Mystery Computer Identified

Thursday, September 15th, 2005
Congratulations, Chris, you guessed it! That's my Heathkit H8 microcomputer kit from the late 1970's. I used that computer for many years; it helped launch my career in computer consulting. It served me well.

The one Megahertz 8080 CPU was fast, but I wanted better performance for my number-crunching, so I built an after-market CPU upgrade kit to allow me to use a Z-80 processor, which I then clock-doubled to TWO megahertz. Man, was that fast! I still have all the accessories for this beauty. While my classmates were buying cars and tricking them out, I built computers and poured money into upgrades. (So what's new?) The only accessory I do not have, but always wanted, was the paper-tape reader/punch. Not that I needed it - cassette was cheaper and faster - but paper tape was cool.

Here's a photo of the H8 computer today, as it sits in my office.


I eventually added an H-19  terminal, which supported both upper AND lower-case letters. This was a vast productivity improvement over the Hex keypad and LED display. Eventually, when I could afford it, I added a and a 5x7 dot-matrix printer and dual 5.25" floppy disk drives. (I upgraded from H-DOS on cassette tape -- I was tired of waiting 20 minutes just to boot!) The media was expensive: $10-$20 per 180K floppy disk! I eventually added dual 8" 128K floppy drives for additional storage.

A few times, I brought my H8 to the college data center, but it was a hassle to haul everything. Still, it was great to make my classmates jealous by getting my assignments done faster than they could using the IBM 360/178 mainframe via the IBM 029 card punch machines or Teletype stations. Once I could afford the $1200 for a 300 baud DC Hayes SmartModem, however, I "found ways" to access the college data center remotely so that I did not drive in to submit jobs.

The Answer to Walter's question:

Yes, Walter, I still have the factory install diskettes -- all of them. In those days, every vendor included the floppy disks! I have my Digital Research CP/M on two 360K 5.25" Floppy diskettes and Microsoft BASIC-80, FORTRAN-80, and COBOL-80. I even have all of my original Microsoft 3-ring manuals.


Yes, I used all of these, once upon a time.

Discussion/Comments (3):

Digital Sandbox Mystery Computer Identified

Mr Mack,

Does your new machine crash more or less frequently than your Tablet? Thank you for showing your eProductivity tool of choice.

Posted at 09/15/2005 21:07:47 by Mike

Digital Sandbox Mystery Computer Identified

How much does this weight ? Seems like a laptop to me, you have keyboard and screen on the machine :D

Ah dual 5 1/4 readers, it was the way to go, One for the OS and one for the software :D

Posted at 09/16/2005 2:09:43 by Thomas BRESSE

I think it’s time to clean out the attic.

I think it may be time to simplify.

Posted at 09/16/2005 11:48:07 by Tanny O'Haley

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