As I was "thumbing" through funet this morning, I came upon the schematics for the IEEE interface modules for the VIC-20 and C64.
In case anyone is looking for parts to fix their boards, many manufacturers have EOLed their GPIB interface chips. National discontinued them 6/99 (SN75160/161), and I can't find *any* reference to the MC3446 chips used in the VIC interface on the Motorola Web site. And as we all know, the MOS 6525 TPI can't be found.
What I did find, however, is a Web site,
http://www.gpib2000.com//These guys make a 40-pin GPIB interface chip which includes all of the line drivers and logic to add a complete IEEE interface to a microcomputer/microcontroller. I will review the data sheets shortly.
This raises an interesting question. In the VIC/C64 interfaces, what did the ROM code provide? Was it only protocol code, or was there Commodore-specific driver code in there? Any clues??
Rich
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Rich Cini
Build Master and maintainer of the Altair32 Emulation project
http://cini.classiccmp.orghttp://altair32.classiccmp.org