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 ...

BYTEC/16

Short update on MDR

Silly MDR flaw

Countdown

Getting closer (slowly)

Base memory PCB soldered

Main CPU board assembly completed

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