Sunday, May 11, 2014

Update on MKHBC-8-R1.

I am pleased to say, that I finished soldering of the CPU card. The work is not done yet though. I need to check all the connections with a multimeter (just by the visual inspection I found one mistake, who knows how many may there be), populate the board's IC sockets with the chips, create a small test circuit (some LED-s I guess, perhaps I'll breadbin the UART again and connect to the MKHBC via serial port), power switch etc., write a test program and test if it works. By looking at the mess of wires on the bottom side of the board, I'd say it will be a miracle if it does work at the 1st try, but I am in my optimistic mood, so I hope it will go just fine.
I added the memory configuration jumper (K1) to the board that wasn't there before (it was on the circuit diagram, I just totally forgot about it when designing layout of the PCB, so there we go):

J5 is a clock speed selector (1 or 2 MHz) and K1 is a memory configuration selector for a future video card.
It took me quite some time today to solder the remaining connections and I am tired and my back hurts, so I am postponing the work on the project to some later time (hopefully much shorter that 6 months like I did the last time, more like in the next few weeks or so at most).

Thank you for visiting my blog.

Marek Karcz