computer programmers?

ChuckR said:

Ah yes,
The "Ada" programming language:

The US Department of Defense mandated "Standard-programming-language"...

Went to school in San Jose, Digital Equipment Corp.
Very good instructor and relaxed classes.
Isolated room in cafeteria for the evil-devil smokers.
Began conversion of FORTRAN missile-tracking stuff to "Ada".
Another two bite the dust:
DEC destroyed by Compaq/HP,
Ada never came...

Bug:
Software bug - Wikipedia, the free encyclopedia
Pertinent PS:
Friend of mine wrote code in Ada (govt contract). His modules worked.
The C-something modules didn't. Moths...
Lady-in-charge 'downsized' him.
He's also still unemployed...
Physics major, U of Ga.
He and I attended same DEC school.

I worked for two years for a company whose initial product was a hardware microcode implemetation of ADA for the DoD. Compilers didn't get any faster than that - also a bitch to maintain and upgrade . By then they had branched into object oriented software modeling and design tools, thank God, although I'm a fan of Lady Lovelace .

<off topic> Redirect </off>

DJG said:

The 6502 from MOS Technology (created by some ex-engineers from Motorola who later sued them and won) has two cycles : fetch & execute . The Amiga keyboard uses a 6502 or 6501. They differ in that one has an internal clock generator and the other one doesn't. My senior project in college was a dual CPU processor board which I wire-wrapped and used one of each, plus a couple of Motorola 6830 multi I/O chips and some 1MHz static ram chips .

Sounds like fun!!!

Did they talk to each other, or each do their own thing?

If they talked, did you do the sw and what hw pins (signals) did the IPC?

I/O, memory-mapped, interrupt/polled? SRAMs 2K, back then? Sounds interesting...

Steve Ciarcia/Byte?

Got more?

They worked independently off shared memory, but one CPU handled the supervisory functions and task scheduling. Communication was through the shared memory and the NMI pin. The memory bus arbitration was pretty lame, because of the simplistic processing cycle - they just access the bus on alternate fetch cycles.

The supervisor was built on top of the basic routines from the KIM ROM (Keyboard Input Monitor) that MOS Tech was offering as a kind of lab for developing 6500 embedded applications. It WAS oodles of fun! I didn't get very far on the supervisor, just enough to get the hardware booted and running, but no real programs were ever executed - by then I had to start working and was starting to get into photography :). That's right, no software was harmed during the making of this board .

Edit: I just checked my board, I mistook the 6500 model - I used the 6512 which was the one w/o the internal clock. The diff between 6501 & 6502 was the clock speed IIRC now. Also I used 7489 TTL memory with 74157 data selector chips to map the 12-bit max addressing per process to the memory space, the 4 MSB handled by the mapping table and the LSBs handled by the processor.

ChuckR said:

Hah,
Happened across this:
(Dual register set: I remembered --> no Alzheimers yet)

Zilog Z80 - Wikipedia, the free encyclopedia

I believe that the Z80 was the workhorse of the Soviet Union in it's space and military sectors:
Solid, dependable, no-frills, no-nonsense, highly-reliable microprocessor.
Compatible with a 'lot-a-stuff'...

The follow-up Zilog Z8000 was also very interesting:
Zilog Z8000 - Wikipedia, the free encyclopedia
I don't think Windows 7 can do this today, can it?
This **** was really fascinating when BillyG and SteveB were writing Basic and pumping the "Seattle Computer Corporation's" 8086/DOS to IBM...

The cool thing about the Z80 was that the dual register sets could be switched in one tick, although you couldn't use them both simultaneously. This gave it a high compatibility with the 8080.

FYI, I was the Zilog Eastern Region Systems Engineer during 1981-82 responsible for the Eastern US & Canada, based out of the Radio City Music Hall building in NYC . I actually had a Z-8000 based system from Zilog / Exxon - a mini-tower that weighed about 100lbs. - which I finally threw out a couple of months ago during some heavy house cleaning.