All, I have completed the schematics for the 6702 chip (or at least completed them as far as I think they need to go). I have sketched out everything - but only done 1 of the 64 bit shift registers (noting that they are all the same; so sketching out one should be good enough). I haven't fully checked the schematics against the netlist (obtained from Pavel's graphics) yet - but I will be quite happy to send the current PDF schematics to anyone who wants a copy. I can then forward a checked copy when I have completed my checking. I plan to issue a further PDF document in the future describing the process that I went through to go from Pavel's graphics to the schematics. I always like to describe 'how' I did something rather than just post the result so that other people can learn from my experiences (see a previous example on Mike Naberezny's website for how the 6702 protection was removed from the Waterloo languages disks of the SuperPET). Interestingly, I have also just got to work (literally today) the visual6702 implementation. it is like http://visual6502.org/JSSim/index.html - but with the graphics and a simulation of the 6702! It doesn't quite give the correct answers yet (it needs debugging) but the results look very promising. I will send out snapshots to anyone interested. Regards, Dave Roberts > Message Received: Dec 26 2013, 11:13 PM > From: "A. Fachat" <firstname.lastname@example.org> > To: email@example.com > Cc: > Subject: Re: 6702 chip > > > Hi Pavel, > > what is the state of the 6702 chip schematics? Have you done them? I know the > 6702 problem seems solved as we have > http://www.zimmers.net/anonftp/pub/cbm/documents/chipdata/6702.txt > now and a working VICE emulation, but it would be nice to have that confirmed. > > Many thanks! > AndÃ© > > On Friday 22 February 2013 02:31:14 you wrote: > > Hello. > > > > I've drawn layers of 6702 based on die shot published on visual6502. As the > > chip was not delayered yet the diffusion and buried contact layers are > > sometimes only guesses as they are not visible when hidden below the metal > > layer. Anyways I succeded in simulation of the chip and the results were > > exactly what expected for repetitive inputs 00-01, 00-03 and 00-81 (hexa). I > > did not test the other sequences because I suppose that they are OK. Maybe > > if someone here has some more elaborate (not repeating) sequence for me to > > test I'll test it. > > > > If no one else wants to do that I can draw the schematic of the chip and do > > some analysis. The chip itself looks quite simply, it consists of 1249 > > transistors. > > Below is the copy of my posting to visual6502 forum - if you try to run my > > simulator don't panic, it's quite slow, it runs for several minutes (some > > 85s on my i7): > > > > ============================================================================ > > = > > > > Hello. > > > > I was thinking if this chip is easy and repetitive enough that diffusion and > > buried layers could be renostructed just by thinking and intuition. I > > couldn't resist and I drew it and simulated it. > > > > Total: http://www.pastraiser.com/pictures/6702/6702_total.png > > Metal: http://www.pastraiser.com/pictures/6702/6702_metal.png > > Vias: http://www.pastraiser.com/pictures/6702/6702_vias.png > ... > > Message was sent through the cbm-hackers mailing list > Message was sent through the cbm-hackers mailing listReceived on 2013-12-27 21:00:05
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