- Yay it works - thanks to SiriusHardware for so quickly blowing my PROMs. Only fault was SENSEA not grounded so it would not run code (but, that was due to a missed solder on my header 0v PIN) and it reset a few times as I had a dry joint on the 9V feed (old 1980's socket is my excuse...).
Seems the IO chip is faulty as I get no RAM at 0800 - hopefully they will replace that for me as they seem fairly reputable (although see later in case it could be a board issue?).
Anyway I typed in the scrolling message and as I have heard described in a review the most fun was had in building it so I thought I would give a go at SiriusHardware MKII PI programmer as in this thread with some hints from the maestro himself (thanks again). Well had a few to drink when I wired the 3v straps and missed the transition from strapping collectors to emitters for the row selects. Duh - reset worked...
so a quick fix and mess up my nice layout and it seemed to start working except for some keys... 4->5 5->7 6->9 7->8 E->9/0 and F gives 6/0. Hmm must have been wired wrong - double checks for shorts and numbers and mistakes and it all seems OK.
Anyway after quite a while I decided to tap out the JM Version 0 board edge with a patch lead to simulate keys. Seems that 6 and 8 are not N/C but give characters 6 and 4 respectively - so the columns (pins 8-3) return 0-9 as clean numbers - I assumed that the two marked NC actually presented 8 and 9 from the BCD to Dec decoder IC13 on a real MK14? Can anyone confirm that? So they should do nothing although with just shorting the selector to the row if they are low it would look like a key perhaps giving the effect I see of 0-9 on the columns.
So it seems I need to wire another connector (without the missing pin) and work out how to modify the programmer to allow for the different layout.
It seems (and its a guess) that the other issue is Pin 13 and 14 are reversed so a different row select is happening.