#: 12398 S7/Telecommunications
    24-Sep-91  19:37:39
Sb: #12388-#IRQ hack
Fm: Pete Lyall 76703,4230
To: Paul Hanke 73467,403 (X)

Scratching old memory cells here...

All the hack does is pass the IRQ from the 6551 chip directly to the 6809's IRQ
line... no stopping at PIA's or multiplexor chips. In the original PAK
configuration, I believe the line (IRQ from the 6551) was originally setup to
go to NMI (non maskable interrupt). This was a bad idea, thus all the little
blue jumper wires. It is now connected to pin 8, which lands on the coco as
either an IRQ or possibly an FIRQ (been too long).

Best advice: try it. I believe you'll have no problems. Hundreds if not
thousands have installed this simple mod with no negative effects.

Pete

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