On 2012-10-08, at 21:40, Gerrit Heitsch wrote: >>> PCB: >>> ===== >>> http://dl.dropbox.com/u/58002657/cbm/c64/Scan-121008-0001.jpg >>> http://dl.dropbox.com/u/58002657/cbm/c64/Scan-121008-0002.jpg >>> >>> On board and worn out with tens of rounds of de/re-soldering.. (full res - above 1MiB): >>> ======================================================================================= >>> http://dl.dropbox.com/u/58002657/cbm/c64/2012-10-08%2020.48.02.jpg >>> http://dl.dropbox.com/u/58002657/cbm/c64/2012-10-08%2020.48.19.jpg >> >> Just in case you'd wonder.. the PCB doesn't show the last gate of LS11 tied to GND, neither VPP of the EPROM to VCC. Those I added on the assembled adapter manually. > > As you know by now, I wondered... Also, I noticed that the trace for +5V to the LS11 is a bit on the long and winded side. I doubt that it makes a difference, but could you add a direct wire from pin 28 of the EPROM? This shouldn't make a difference I agree but I added the wire as requested - no difference. > The next step, if this fails would be to take out the 74LS00 and bridge the signals so that you only have 1 char set and see if that makes a difference. (Take out the 74LS00 and put a bridge between pin 6 and pin 2 of the now empty socket, assuming your schematic matches the PCB) I updated the schematics with things I omitted in the first version. Although the unused gate should not influence the others (should it?) I preferred to tie it down. I also found the VPP connection missing and updated both the proto and the schematics. As for removing LS00 I did that already previous night... ;-) Funny part is that machine becomes even /less/ stable in that case. The machine boots 1 out of 4 times (and I never even get the striped IDE64 guru alert) when I bridge the 2 and 6. With LS00 in place it does 8 of 10 (more or less). P. S. Shall we take this off the list? -- SD! Message was sent through the cbm-hackers mailing listReceived on 2012-10-08 21:00:14
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