About that audio/video output connector - I built a small break-out box for this connector and discovered that pin #5 was a high impedanceral-clan wrote:Tweaking the VIC-20's video output:
http://sleepingelephant.com/denial/wiki ... djustments
I compiled this info from postings on Denial, so please, anyone with more technical knowledge feel free to edit the article.
("pin #5 - video high", per "Personal Computing on the VIC-20 computer guide" and "VIC-20 Programmer's Reference Guide") that measured
over 120 ohms and, therefor, did not have enough "umph" to trigger the input circuits of the monitor. Pin #4 @ 75 ohms ("pin #4 - video
low", ibid) produced an excellent picture as expected. Since the "monitor" was a 25 inch t.v. screen with direct (known as 'baseband') audio/
video inputs (yes, it had antenna inputs, but, by-passing the R.F. circuits produced a cleaner picture), I didn't wont to sit in front of such a
large screen (I'm not a kid now - such antics are not that appealing anymore). So, I added a couple of RCA jacks to the box for audio
and video connections to the t.v. Connecting cables were ordinary Radio Shack audio cables (RCA male-to-RCA male). And it worked!! They
passed 4 MHZ (yes - MEGA!!) with no problems!!! Amazing what you can find while experimenting!! I hope this helps - and - I hope I'm in
the right forum for this. What say yee ral-clan??!
Phil Potter.
