From owner-coco@PUCC.PRINCETON.EDU  Tue Sep 26 20:45:31 2000
Date:         Tue, 26 Sep 2000 22:44:28 EDT
From: A coco hacker who doesn't want any more spam!
Subject:      Controller Hack
To: COCO@PUCC.PRINCETON.EDU

I found it!  The mod was described by Dr. Marty Goodman,
but I didn't note the issue of Rainbow that it was in.
The hack interrupts the SCS and sends _only_ the
signals from FF40-FF4F to the floppy controller.  It
involves inserting a 74LS32 in the controller and
cutting the SCS line.  Then pin 1 is connected to
the CoCo side of the SCS (#36) and pin 3
reconnects the circuit to the floppy side of the SCS.
Connections to the 74LS32 are as follows:

Pin 1   - SCS In (36)
Pin 2   - A4 Address line (23)
Pin 3   - SCS Out to controller's 74LS139
Pin 7   - GND (34)
Pin 14  - Vcc (+5V) (9)
Pins 4,5,9,10,12, & 13 are all tied high to Vcc (9)

This should decode the SCS.  If someone can locate
Marty's article to confirm this, we can all rest
easier!

Tony DiStefano did something very similar for
the Improved Printer Adapter in the Nov. 1987
Rainbow; he mounted the board inside the CoCo,
cut the SCS at the internal connector, and used a
74LS139 for decoding.  Marty's hack is simpler
and leaves the CoCo untouched.

-- Jim