My Old-School Distraction

erco

Senior Member
Only old timers here might appreciate my latest purchase. I finally bought a missing faceplate to complete the IMSAI 8080 I inherited from my Dad. Been looking for a "deal" on one of these for nearly ten years, no such luck. I had to pony up $600+ for this unit, but at least it's in mint condition. The rest of the computer was useless without it.

Likely a long-term labor of love to get this gal going. Hundreds of PCB contacts and switches to dexoxit! Even then these computers are not particularly useful. They make an 08M2 look like rocket science.
 

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PhilHornby

Senior Member
I have to admit, I've never heard of this machine - but I know what that console was inspired by ...
...I could kick myself, for letting one of these get thrown away in the late 1980's :(

(You really need the power on and the LEDs illuminated, to get the full effect)
 

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premelec

Senior Member
A MITS clone - now if you can only find some S-100 bus stuff... I started later with Sinclair kit... Used to enjoy mercury vapor rectifiers - what a long strange trip it's been to these tiny clever ICs
 

inglewoodpete

Senior Member
The IMSAI 8080 was one on the early development systems that inspired me to get into microprocessors.

And I did my first program development at technical school on a PDP11/70.

I even made a couple of S100 boards in the mid-80s. Wire-wrapped the first one! I must be revealing my age.
 

lbenson

Senior Member
I even made a couple of S100 boards in the mid-80s. Wire-wrapped the first one! I must be revealing my age.
I wire-wrapped a Motorola 68000 S100 board and wrote a 68000 assembler CP/M emulator to run on it with floppy disk reads fed from the Z80 on S100 main processor board, all because I thought the IBM PC had gone the wrong way with the paged 8086--I mean who wouldn't prefer 1 megabyte of flat memory to 64K pages?

Nice thing about debugging on the 68000--you could single step it at human speeds with a pushbutton.

I made a nice wooden box for my S100 Z80 system, and took it into my computer-center place of business. One of the more tech-savvy guys (head of networks), said, "What would anyone ever do with a toy like that?" ('Course he went on to form a business and make millions, and I didn't.) Now we all have so much more in our pockets. What a long, strange trip it has been.
 
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PhilHornby

Senior Member
Going way back: I "cut my teeth" on the Intel 8048.. Does anyone else remember it??
I know it was used as the keyboard controller, in the original IBM PC.

One of the more tech-savvy guys (head of networks), said, "What would anyone ever do with a toy like that?" ('Course he went on to form a business and make millions, and I didn't.)
I remember reacting exactly like that, when I first saw a PC - however, I also failed to form a business and make millions :) .

The future was all documented here ;) :-

"Now the Chips are down" - BBC Horizon documentary 1978 (or here, on Youtube, for viewers outside the UK)
 

papaof2

Senior Member
At one point I was the system administrator for a roomful of Unix-based PDP 11/70s with the washing machine size 300MB removable pack hard drives. I couldn't get the C source code for certain programs that we used so I learned PDP11 assembly and did direct edits on the executables. Not a big deal after I had done the same to fix a library for the C compiler on my 6809 system. Once you're doing binary edits on executables, it's all hex or octal ;-)
 

lbenson

Senior Member
my first attempt at programming back in the early 80s
Da Bomb! Wish I had pics of my first box.

Once you're doing binary edits on executables, it's all hex or octal ;-)
On an IBM mainframe in the late 70s, I figured out that I could often avoid the 1+hour turnaround for the compile queue (COBOL program), by editing the executable and making small changes to data or execution by inserting jumps and then fixup assembler code. Instant turnaround to re-execute. Might get in a half-dozen cycles before having to re-compile.
 

kranenborg

Senior Member
Only old timers here might appreciate my latest purchase. I finally bought a missing faceplate to complete the IMSAI 8080 I inherited from my Dad. ....
.
... Hundreds of PCB contacts and switches to dexoxit! ...
Hi all,
My first experience with (serious) soldering and machine language programming was with the Elektor SC/MP kit that I purchased as a teenager somewhere in 1982/83 (but apparently made available in 1978):

elektorscmp.png

Like the IMSAI it used bit switches for programming, but in my case fiddly DIP-switches were used for both address and data ... . I still recollect the sense of accomplishment being able to execute the first simple programs, although I never made it to the NIBL-Basic extension. But luckily I got a final reprise since we now have the PICAXE with a much better and friendlier BASIC-programming environment!

All of this is preceded by my experiences with electronics (starting way earlier when my age was still a single-digit figure) using the revered Philips EE kits (EE2040, EE2003 etc.etc.) , and for me there is still a direct and active link between those kits ( http://ee.old.no ) and the Picaxe:




By the way, the earlier versions of these kits seem to have been very popular in GB too: https://www.vintage-radio.net/forum/showthread.php?t=63719

Thanks for the memories!
/Jurjen
 
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jscottb

Active member
Nice @erco!

I still have my Micro Professor MPF-I I got in 1982. I worked a long time to get money for it! I started building a Z-80 computer based on the William Barden book, Z-80 microcomputer design projects. Finished it in '83 I think. All wire-wrapped with my Radio Shack wrap tool. Bought my first Z-80 from Jameco!
 
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