Video circuit of PET64/Educator 64

[Blacklord]

Original post by Robert Bernardo

On comp.sys.cbm Ruud Baltissen posted a brief message, saying that he had re-engineered the video circuit of the PET64/Educator 64.  He also forwarded the schematic to those who asked for it.  I received a copy and passed it on to Ray Carlsen and Larry Anderson (Larry owning an Educator 64).  This is what Ray had to say about it, "Thinking backwards, it appears Commodore used PET monitors with old C64 motherboards to make their Educator64 computers. So, they had to make up some kind of interface circuit to match the one wire (composite) signal from the 64
VIC chip to the PET monitor (three wires: video, H and V sync). It appears Ruud's circuit duplicates that interface."

Idea -- if your PET motherboard is totally gone but the monitor is o.k., take out the PET motherboard, hack in a C64 keyboard, build Ruud's video circuit, and connect up to the monitor.  There you go... faux Educator 64!  :-D

Truly,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug