For assembly language geeks only - What's your favorite CPU?

[HopeHoops]

Direct machine code applies as well, but assembly is generally easier to maintain.

[Major Nikon]

1. Univac 9000 series

[HopeHoops]

2. Never tried that one - was it fun? How many accumulators? Index registers? Fun addressing tricks?

[Major Nikon]

3. It was nothing like a microprocessor

It's been 20 years since I've even seen one, much less worked on it so I don't remember all the particulars. The basic processor was designed back in the late 50's. It was cool as hell to program. All you had was assembler code. There were no higher level languages. It had 32 bit everything. Memory could be read 32 bits at a time. All buses had a 32 bit data path. All registers were 32 bit. Input/output was 32 bits of data, parallel. The clock speed was 5 mhz, but it screamed with performance. One instruction could do what would take you as many as 16 lines of code on an 8 bit processor like the 8080 series. You could do multiple things with one line of instruction. For instance, you could take 32 bits out of memory, load it into a register, logically or it with another register, then put the result back in memory all with one line of code. It had all sorts of registers. The panel on the front had hundreds of lights. It had lights for each register, so you could single step your program and see exactly what was happening with each instruction. No monitor, only a teletype. Programs were 'assembled' on IBM punch cards and read through a card reader. The teletype had a paper tape writer/reader that you could store data or short programs with. Programs were written to magnetic tape. Later we got 100 mb hard drives that were as big as washing machines. Memory was 128K of little magnetic donuts, later expanded to 256K solid state memory. Very cool stuff. It was the golden age of computers.

[HopeHoops]

4. LOL! Yeah, I actually understood all of that. I used to call such machines....

"Two refrigerators and a beer cooler".

One of the refrigerators was usually a vacuum 9-track tape drive, the other the main computer. The beer cooler usually held something AMAZING like 300MB on 12 platters the size of an XL pizza pan.

Oh, and remember the Bell-212A acoustic couplers we had to use?

[Major Nikon]

6. Ours was more like a whole row of refrigerators

We had a total of 8 processors. Each processor was as big as two refrigerators.

We never used acoustic couplers. We used modems that were as big as a microwave that were connected to dedicated 4 wire phone lines. I don't remember what protocol we used. I think the original speed was 300 baud, which was later increased to 9600 through upgrades.

[HopeHoops]

8. Wow - you were ahead. Bell 212A was 120 baud.

[Major Nikon]

12. The 4 wire stuff was more advanced

and could handle more bandwidth. Very expensive, though, and very big phone bills.

[HopeHoops]

13. DSL is pretty fucking cool, eh?

[madinmaryland]

5. I learned on a DEC PDP-11/70 mainframe

[HERVEPA]

7. Burroughs L-2000

Had to compile to produce paper tape of Burroughs 5500.

[hunter]

9. I've written assembly for all of those.

I felt I had to vote for the 6502 because I was crazy for the Atari 800.

Another one of my favorite CPUs was the 1802, which was used in many spacecraft.

http://en.wikipedia.org/wiki/RCA_1802

[HopeHoops]

11. Yeah, I know 65XX really well - Apple II and C=64.

[hobbit709]

10. TI-9900