[SiriusHardware]

A quick update, I've had the new 'Slothie' Issue VI connected up to the pi-uploader, first of all I used the 'Key14' test utility to check the layout of the keypad connector and of course it was OK, all key presses individually sent to the PCB via the edge connector were coming up as the correct characters, commands or actions, including reset. This was to be expected as the timings for things like the length of a key press are much more generous in the key14 script than they are in the send14 script, where the delays were eventually pared to the shortest possible length consistent with everything still working - that was on my original issue II, 4.43MHz machine.

I used key14 to enter some test code, and naturally I chose the original test routine from #100 of this thread to honour the great man himself, image #1 attached.

The big surprise today was that the original 'send14' timings - including the original reset-hold and reset-release timings - work perhaps 98% of the time with this new PCB with a 4.00MHz crystal in it - I've uploaded the 'Message' program to it over and over and over again, and only once did I see a problem indicating that the timing was a bit tight, the letter 'J' of 'Jolly...' was corrupt on one occasion. I assume if I slow the timing a tiny bit that will then shift to 100% perfect entry. But otherwise, it's working better than I dared hope.

One way in which my PCB probably is different from Tim's is the four resistors near the upper left corner of the keypad and the four at the top right hand corner. The values originally given for these eight resistors is pretty arbitrary, all 1K2, but up to about 15K, I think.

My original MK14 has 4 * 4K7s for the four near the keypad and 4 * 6.8K for the four at the top right near the PROM, so that's what I have also fitted in the same positions in the new PCB.