BYTEC/16

Short update on MDR

Dec

5

2010

I reviewed the microcode while implementing the MDR workaround I discussed yesterday. I realized that the problem affects currently only 5 instructions, namely: ADD AH, (SP) SUB AH, (SP) CMP AH, (SP) SHL AH SHR AL I took advantage of MDR clearing whenever I manipulated the low or high byte of A register, using the ...

Silly MDR flaw

Dec

5

2010

I have come across the first real design flaw in my CPU. By design flaw I mean a real design flaw, with something functioning not exactly as designed, not an accidentally swapped wire or a simple bug in schematics. The good news is that it going to be fairly easy to fix. The bad news ...

Countdown

Nov

28

2010

I think I am ready to declare readiness for a final countdown. For the last few weeks I have been hunting for bugs in my wiring and running all sorts of unit tests. I have completed the ALU board wiring, and I think the machine is very close to successfully running some kind of useful ...

Getting closer (slowly)

Oct

19

2010

It’s been nearly a month since I last posted. Unfortunately, there hasn’t been much progress recently. I have only a few hours every week which I can fully spend on project activities. Big part of the reason is that I will be moving from Poland to Germany for a while, and there is a lot ...

Base memory PCB soldered

Sep

21

2010

Soldering is so much faster than wire wrapping, and my last evening’s session proves that. I managed to complete my base memory PCB in two hours, from workshop setup to actual soldering to plugging all parts into their sockets. This exercise was so encouraging that I am seriously considering building the ALU part of the ...

Main CPU board assembly completed

Sep

20

2010

I have finally completed wire-wrapping the CPU’s main board. It consists of 82 ICs, 51 power filter caps, 26 resistors, one oscillator, one power led, one reset button, two HP hexadecimal displays, two 64-pin IDC headers, a molex power connector and lots of AWG 30 kynar wiring. In fact, there is around 1600 wires, and ...

Short update on MDR

Silly MDR flaw

Countdown

Getting closer (slowly)

Base memory PCB soldered

Main CPU board assembly completed

Homebuilt CPUs WebRing

Join the ring?