View Single Post
Old 6th Sep 2020, 11:11 pm   #29
Buzby123
Heptode
 
Buzby123's Avatar
 
Join Date: Oct 2011
Location: Culcheth, Cheshire, UK.
Posts: 637
Default Re: I found it !. A very sorry looking MK14

Quote:
Originally Posted by SiriusHardware View Post
... but at the time the caps were only available in red or blue so I couldn't have the command keys picked out in a third colour ...
A third colour ?. Why did you need three ?.

My digits 0-F were in blue, and Mem,Term,Go,Abort in grey. That's all the matrix keys done. ( Actually, the 0 was grey, 'cos I was a blue short. )

Regarding my progress, it's hit a tricky part. The three banks of LEDs around the breadboard are there to show the states of the 8154 IO pins, and the flags etc. from the CPU. All these signals are from the long edge connector.

With no MK14 board in place there should be no LEDs lit, but some are. The LEDs are driven by simple transistor circuits, but getting at them is going to be difficult.

I must have fitted the LEDs and sockets first, then put the veroboard onto the pins of the LEDs/sockets, then soldered. This means I have to desolder all the sockets to remove the board. ( I can pop out the LEDs ).

It's obvious I thought they would never need fixing in the future. Isn't hindsight wonderful !.

Cheers,

Buzby
Buzby123 is offline