does the protovision 4 player adapter work with the vic?

[groepaz]

For the Starbyte (and similar) adapters, pretty surely the reason is that it was easier to do on a single sided Board. The ppl doing this were software people, and the Aaapters were produced in very small volumes (likely by the ppl behind the games themselves), so basically hobbyists doing it "at home". That said, i'd be curios to see one of these adapaters - so far noone could be found that even owns one of them (i reverse engineered the wiring from the code). Who knows if they exist in the wild at all

[brain]

That was the only reason I could see for such variety.

With the differences between the CIA and VIA, can the same process the code uses to read SP2 and CA2 in the 64 be used to read the respective lines in the VIA?

Jim

[groepaz]

Does shiftregister out- and input exist on the Userport on the VIC? If so, i don't see why it wouldnt work, it's really trivial afterall

[brain]

PA2 on the 64 (M) is VIC CB2
SP2 on the 64 (7) is LIGHTPEN (PA5) on the VIC.

So, SP2 is easy to grab, and it looks like you can coax CB2 into providing the needed result.

Interestingly, though, VIC already plans PA2,3,4,5 as joystick #2 direction pins, so If you're already using the VIC second joyport adapter, PA5 will be unavailable.

JIm

[Mike]

Interestingly, though, VIC already plans PA2,3,4,5 as joystick #2 direction pins, [...]

Erm, no. The directions JOY0..2 on pins 4, 5, 6 and "light pen"/fire on pin 7 of the VIC userport just mirror those on the 9-pin joystick connector (and are missing the right direction!) - no provision for a second joystick here.

...

IMO, using the Protovision adapter to provide a second and third joystick on a VIC-20 is about as good as it gets. If someone has bought it for the C64, it also works on the VIC-20 (which was the question put in the OP!), and some idiosyncrasies of it have been cleared up. Further discussion about (better?) alternatives should go into an own thread.

[brain]

Ah, I missed that those are JOYPORT 1 pins. Duly noted.

Back in the day, there were second joyport adapters for the VIC. That's what I thought those were. IN any case, I wonder what pinout they used. (Can't check right now, but I know it was a thing).

Jim