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 9/15/2005 9:07:47 PM 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 9/16/2005 2:09:43 AM by Thomas BRESSE

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

I think it may be time to simplify.

Posted at 9/16/2005 11:48:07 AM by Tanny O'Haley

Discussion for this entry is now closed.