Comments on: Commodore 64 IRQ Bicolor LED https://www.nightfallcrew.com/04/03/2011/commodore-64-irq-bicolor-led/ Lightning in the Dark Thu, 11 Apr 2024 19:18:05 +0000 hourly 1 http://wordpress.org/?v=3.4.2 By: Drago Kraner https://www.nightfallcrew.com/04/03/2011/commodore-64-irq-bicolor-led/comment-page-1/#comment-149456 Drago Kraner Sun, 26 Jan 2020 16:02:31 +0000 http://www.nightfallcrew.com/?p=5638#comment-149456 Can, someone share pcb design Can, someone share pcb design

]]> By: xAD / nIGHTFALL https://www.nightfallcrew.com/04/03/2011/commodore-64-irq-bicolor-led/comment-page-1/#comment-45997 xAD / nIGHTFALL Mon, 01 Sep 2014 21:32:56 +0000 http://www.nightfallcrew.com/?p=5638#comment-45997 <a href="#comment-45799" rel="nofollow">@Tim Harris </a> Hi Tim, you have made a nice work!. @Tim Harris

Hi Tim, you have made a nice work!.

]]> By: Tim Harris https://www.nightfallcrew.com/04/03/2011/commodore-64-irq-bicolor-led/comment-page-1/#comment-45799 Tim Harris Fri, 29 Aug 2014 07:56:07 +0000 http://www.nightfallcrew.com/?p=5638#comment-45799 This is a great mod for the 64 and we have made a small plug in PCB, have a look at - http://blog.sharewareplus.co.uk/ This is a great mod for the 64 and we have made a small plug in PCB, have a look at -

http://blog.sharewareplus.co.uk/

]]> By: RandyInLA https://www.nightfallcrew.com/04/03/2011/commodore-64-irq-bicolor-led/comment-page-1/#comment-2477 RandyInLA Mon, 30 May 2011 23:23:06 +0000 http://www.nightfallcrew.com/?p=5638#comment-2477 The bicolor LED I bought at Radio Shack (part: 276-0012) only had two leads, not three. To make this work with the schematic, simply skip the connection from GND to the middle lead of the LED, as it doesn't exist. Certain c64 applications (eg.GEOS) cause the LED to stay orange (turning on/off very fast). I don't like the look of the orange, so I wanted a simple way to turn the effect on/off that didn't involve opening the c64. This can be achieved by either: 1) Adding a 330Ohm resistor in between the IRQ line and pin 1 of the 7404 and then add an externally mounted SPST switch wired to short pin 1 of the 7404 to GND when closed. Shorting to ground overrides the IRQ signal, leaving the LED red. 2) Adding an externally mounted SPDT switch, connecting the middle pin of the switch to pin 1 of the 7404 then one of the other switch pins to the IRQ line and the last switch pin to GND. The switch now chooses what is connected to pin 1; IRQ or GND. Cheers! -=Randy The bicolor LED I bought at Radio Shack (part: 276-0012) only had two leads, not three. To make this work with the schematic, simply skip the connection from GND to the middle lead of the LED, as it doesn’t exist.

Certain c64 applications (eg.GEOS) cause the LED to stay orange (turning on/off very fast). I don’t like the look of the orange, so I wanted a simple way to turn the effect on/off that didn’t involve opening the c64. This can be achieved by either:
1) Adding a 330Ohm resistor in between the IRQ line and pin 1 of the 7404 and then add an externally mounted SPST switch wired to short pin 1 of the 7404 to GND when closed. Shorting to ground overrides the IRQ signal, leaving the LED red.
2) Adding an externally mounted SPDT switch, connecting the middle pin of the switch to pin 1 of the 7404 then one of the other switch pins to the IRQ line and the last switch pin to GND. The switch now chooses what is connected to pin 1; IRQ or GND.

Cheers!
-=Randy

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