Thursday, November 15, 2012

MKHBC-8-R1 - CPU bus completed.

After a long break (as usual), I did some work on MKHBC-8-R1 again. The progress is slow, project definitely lost a lot of momentum, but don't worry I did not abandon it. In fact, I am about to give it some more time in hope to have some working parts before the end of year.

Today I sort of finished soldering the CPU bus by wiring the remaining +12V line and 8 I/O lines from I/O decoder. About 25% of the back plane or mother board is finished. Remaining (To Do) mother board sections are: I/O Expansion Bus, Prioritized IRQ Controller, Power Supply and Front/Control Panel. And of course the cards that will go into CPU bus and I/O bus sockets. I will start with CPU, RAM and RS-232 cards.

Here is how the mother board looks like now:

The section I soldered today (lower right corner, blue wire).
Quality of connections needs some improvement. My age, crappy soldering iron and lack of soldering rosin (rock) do not help.
View on the entire CPU bus section (down side of the board).
Top of the board (currently still almost empty).
Just another view of the down side of the board.
I can not wait for it to be ready. I have so many plans and ideas for expansions. After CPU/ROM/RAM and RS-232 cards I think I am going to do some sort of mass storage device (CF and/or SD card based) before I proceed to keyboard and Video Controller. BTW - yesterday I purchased on e-bay an unused TI99-4A keyboard. This will be great for my system's console. Mass storage and console (keyboard and video card) are absolute priority - I want MKHBC-8-R1 to be a completely standalone system.

That's it for today. Thanks for reading.

Marek Karcz