Hello! Here is a forwarded message from William Levak, who has uploaded some IEEE-488 drive ROMs and is working on a listing of PET ROMs, among other things. Does anyone know more about the SFD 1001, the C128 PLA, or the 8701/7701 chip used in the newer C64s and in the C128? Marko ---------- Forwarded message ---------- Date: Thu, 5 Feb 1998 23:16:10 From: "William M. Levak" <wlevak@umich.edu> To: Marko Mäkelä <msmakela@cc.hut.fi> Subject: Re: several messages The last 2K of the PET character files did not look like reversed characters. They looked like fill characters, mostly FF, as if he read the 2K ROM as a 4K ROM. Sorry, I don't have any schematics of the SFD 1001. For some reason Commodore did not support that drive and never supplied any information except parts. I have been working from 8250 schematics which are functionally equivalent and have the major parts in common. As for ROMs, they are supposedly equivalent to the Motorolla 68764 or 68766, but I have never been able to get these to work in an 8250. C128 PLA: The C128 Programmer's Reference Guide says this is a programmed version of the Commodore 48 pin PLA, part # 315011. Does anyone know anything about the 8701 clock chip in the c64 and C128? >From the schematics I can get a pinout, but no specifications on it's operation. It seems strange that Commodore should make a custom chip with 6 pins unused. It's probably a copy of something else.
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