Re: Mk14 vdu
I repeated last night's experiments with 100pF capacitors. As with the 47pF capcitors fitted I never get the reverse-C appearing third from right, and unlike then, with the 100pFs fitted I don't see any flashes of interference in the empty digits 3rd and 4th from right no matter how many addresses I step through. So far so good.
On to Charset, writing to 03xx and watching 0Fxx and 0Bxx on the OrtonView screen. Previously, I was seeing the bytes at 0F1B and 0B1B both changing to 'O' within a minute or so of starting the program.
I still get 0B1B changing within that time scale but 0F1B no longer does, so tomorrow I'll try going higher again with the capacitors. The value will depend largely upon what I can find at work, but I'm thinking perhaps 180pF.
I've also ordered a flat-pack 44-pin 16F877-20, which I'm going to put on one of my spare Microchip '44-pin-demo' PCBs for my permanent build of the OrtonView. One reason to do that is that those boards already have the supply rails, reset circuit, crystal circuit, ICSP header provided on them, another is that they are quite compact. My current 'build' of OrtonView is quite unruly, much more so than Tim's, with quite a few long, flying wires between the PIC PCB and the 64-way DIN connector. I'll be able to make the wires a lot shorter if I use one of those PCBs.
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