Re: 6702 chip

Date: Fri, 27 Dec 2013 21:07:45 +0100
Message-ID: <21297612.7471388174865093.JavaMail.www@wwinf3724>

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 

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 - 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.


Dave Roberts

> Message Received: Dec 26 2013, 11:13 PM
> From: "A. Fachat" <>
> To:
> 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 
> now and a working VICE emulation, but it would be nice to have that confirmed.
> Many thanks!
> Andé
> 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:
> > Metal:
> > Vias:
> ...
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Received on 2013-12-27 21:00:05

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