VIC-20 Paddle Notes

From: Jim Brain <brain_at_jbrain.com>
Date: Sun, 22 Nov 2009 15:22:07 -0600
Message-ID: <4B09AB7F.5080202@jbrain.com>
Just a note, in case it's not common knowledge.

I was fiddling around with a PS/2 mouse converter for the 64, and I 
decided to see if the VIC POT lines would respond to the same treatment 
used by the 1351 mouse.  It appears the VIC POT lines work the same way 
(clamp to 0, let time elapse, then measure length of time to reach 
charge threshold) and use the same conversion frequency (512 cycles per 
conversion).  However, it appears they only clamp the line for 64 
cycles, so charge cycles start at Tclamp + 64uS, not Tclamp + 256uS.

Probably everyone knows this but me.  Still, if my empirical evidence is 
incorrect, please let me know.

Jim

-- 
Jim Brain, Brain Innovations                                      (X)
brain@jbrain.com 
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times! 
Home: http://www.jbrain.com


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Received on 2009-11-22 22:00:05

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