[Coco] what was done to my modpak Re: modpack hack was Re: Drivewire question

[Darren A]

On 3/28/09, Willard Goosey wrote:
>
> This is the current status of the hacked modpak in question.
>
> I haven't done anything too it but brush off the dust and stare
> suspiciously at it.
>
> on the ROM, pin 20 is tied to pin 28

That would tie +5V (28) to the Chip Select input (20) meaning the ROM
cannot be selected.

> on the 74133, the trace from pin 10 to rom pin 7 cut
> on the 74133, wire from pin 10 to 7404 pin 2.

Disconnects the 74133 from A3 and connects it instead to the output of
inverter gate A.

> on the 7404, wire from pin 1 to rom pin 8

Connects the input of inverter gate A to A2.

> on the 6651, trace from pin 2 to rom pin 8 cut

Disconnects the 6551's CS0 input from A2

> It looks the ROM has been re-addressed?

No. It is changing the decoding for the 6551 but does not do it in a
way that make any sense to me. The last two items seem okay, but not
the others.

The proper method (to get the RS232 pak decoding) would be to cut the
trace from ACIA pin 2 to Rom pin 8. Then connect Rom pin 8 to pin 1 of
the 7404 and ACIA pin 2 to pin 2 of the 7404.

Darren