Audio to expansion port

[mathop]

Hi. I have a VIC 20 CR board with a bodge wire on the back that appears to connect the audio pin of the VIC chip to pin Y on the expansion port via a 1K resistor. What does this actually do? Are there any cartidges that use this?

Apologies if this has been answered already, I did a quick search on here, but I could not find anything.

[srowe]

Hi. I have a VIC 20 CR board with a bodge wire on the back that appears to connect the audio pin of the VIC chip to pin Y on the expansion port via a 1K resistor. What does this actually do? Are there any cartidges that use this?

Do you have a picture? Somewhere I've seen a schematic this this labelled as "Audio In".

Edit: here it is

[mathop]

Hi. I have a VIC 20 CR board with a bodge wire on the back that appears to connect the audio pin of the VIC chip to pin Y on the expansion port via a 1K resistor. What does this actually do? Are there any cartidges that use this?

Do you have a picture? Somewhere I've seen a schematic this this labelled as "Audio In".

I did not take a picture of the other end of the wire. In the mean time I desoldered it because I could not see what use it could possibly have. Also since pin Y is listed as "NC" in the Reference Guide.

[Mike]

This bodge wire is ex factory and connects the cartridge port pin Y to the audio amplifier on the first revision of the CR board. It is officially documented in the Technical Manual, page 22:



Later revisions of the CR board incorporated the wire into the board layout.

Apologies if this has been answered already, I did a quick search on here, but I could not find anything.

See here, for example: https://sleepingelephant.com/ipw-web/bu ... udio+pin+Y.

[mathop]

Thanks, so this appears to be some kind of official thing.
But what are the applications for this? Are there any?

[JonBrawn]

You could design a cartridge with a SID in it and feed the output back using pin Y so that it comes out through the regular AV DIN connector on the back of the machine.