Paddle problems with Vic20..

Post by **Jeff-20** » Fri Dec 22, 2006 2:48 pm

I was just going to ask if anyone has successfully programmed the 1351 to work with the VIC. I still want to believe it is possible...

eslapion · Post by **eslapion** » Fri Dec 22, 2006 4:45 pm

Jeff-20 wrote:I was just going to ask if anyone has successfully programmed the 1351 to work with the VIC. I still want to believe it is possible...

That would require telling the 6560/6561 to change the rate at which it resets the paddle capacitor. Unfortunately, this rate is hardware fixed at Phi2/512 or about 2000 times per second.

Mikam73 · Post by **Mikam73** » Fri Dec 22, 2006 6:38 pm

Jeff-20 wrote:I was just going to ask if anyone has successfully programmed the 1351 to work with the VIC. I still want to believe it is possible...

How about some external device between Vic20 and mouse that would do the trick.. Mouse dont necessarily have to be connected to joystick port..

'Ok..ok.. I go back, bake the ham..'

ral-clan · Post by **ral-clan** » Fri Dec 22, 2006 8:24 pm

Yeah, and as for paddle jitter, perhaps it would be possible to build an external device to correct this.

Schema · Post by **Schema** » Sun Dec 24, 2006 8:25 am

I'm not sure if an external device would help with paddle jitter. The problem is inside the VIC, at least in my case.

I simply hooked an ordinary resistor up that matched the 1/2 way point of paddles, and the value read by the VIC still jittered!

ral-clan · Post by **ral-clan** » Sun Dec 24, 2006 10:52 am

Is it a simple capacitor that needs replacing?

the dude of dudes · Post by **the dude of dudes** » Mon Dec 25, 2006 1:06 pm

eslapion wrote:
Jeff-20 wrote:I was just going to ask if anyone has successfully programmed the 1351 to work with the VIC. I still want to believe it is possible...
That would require telling the 6560/6561 to change the rate at which it resets the paddle capacitor. Unfortunately, this rate is hardware fixed at Phi2/512 or about 2000 times per second.

The SID operates on a 512us cycle as well. Maybe the caps are slightly different than the VIC's. I'm (endlessly) working on a PS/2 interface for the 64 to emulate a 1351 mouse. It wouldn't be too difficult to add compatibility for the VIC as well. I got a copy of the 6560 datasheet off Zimmers, but there's no data on the A/D convertor cycle. If you have any more info on it, please post it here. Meanwhile, I'll try my prototyped board on a VIC and see what the POT registers show. I can easily change the timing on my board to match the VIC since it's PIC based.

wiskow · Post by **wiskow** » Fri Aug 29, 2008 9:54 pm

Schema wrote:I'm not sure if an external device would help with paddle jitter. The problem is inside the VIC, at least in my case.

I simply hooked an ordinary resistor up that matched the 1/2 way point of paddles, and the value read by the VIC still jittered!

Sorry about digging up an old thread... But I was just wondering, did anyone come up for a fix for the "paddle jitters" on the VIC-20???

ral-clan · Post by **ral-clan** » Sat Aug 30, 2008 5:37 am

I second that query: it's amazing that the community has come up with complicated hardware like the Behr-Bonz, MegaCart, etc. but something (simpler?) like the jitter (which affects almost all VICs) has not been solved. I only wish I had the skill to help.

wiskow · Post by **wiskow** » Sat Aug 30, 2008 10:29 am

Through my own personal tests, I've found that paddles that work just fine with no jittering on a C64 have the jitters when used with a VIC-20. And the jittering is worse on some VIC-20's than on others, so I'd have to agree with Schema's theory that the problem lies somewhere inside the VIC-20 itself. It's apparently something inside the VIC-20 that degrades over time...

eslapion · Post by **eslapion** » Sat Aug 30, 2008 11:57 am

Replacing the two small capacitors between the paddle lines and the 6560 is the only solution I can think of.

These degrade over time. Perhaps using military grade ones would help the solution last longer.