On 07/07/2012 03:17 AM, Bil Herd wrote: > Are you going to mention how we had the polaroid's of the Signetics part > up in the chiplab? When you did your own version of the 82S100, did you just convert the design into a mask-programmed version of the 82S100 or did you implement the logic terms with random logic? I assume it was just a mask programmed 82S100 in the end... > The PLA's were > in some way not very boring as they were our last salvation to pull a > problem out of the fire, and our chance to impart any coolness in logic. From what it does, I always thought that replicating the function would have taken a LOT of TTLs which would have increased space and power requirements. It's not without strangeness though... Watching the _CS signal for the Char-ROM of the C64 on a scope shows some very strange curves. Like LOW, followed by a maybe 20ns HIGH, then another 120ns LOW and finally HIGH again (resulting in the CPU not getting data from it after all!). Or for the VIC: About 80ns LOW, then 120ns HIGH and only then finally LOW for VIC access... Gerrit Message was sent through the cbm-hackers mailing listReceived on 2012-07-07 13:00:05
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