[Coco] RS-232 Pak Back to Stock

[Kip Koon]

JEB,
My catalog number 26-2226 Deluxe RS-232 Program Pak also has a jumper
soldered between E1 & E2.  
There is a second jumper between E4 and the tiny solder pad  between E3 and
"1" a few millimeters away.  
It still has the mask programed rom from Motorola numbered SCM95046P with a
second number 8041332, then TANDY (C) 1983, and manufacture's date code
8441.  
My 6551 is actually a socketed GTE(Greek letter mu in logo) numbered
G65SC51PI-1, manufacture's date code 8440 chip.  
There is a trace cut on pin 4.  Pin 4 is the NMI# signal pin back to the MPU
which is not used thusly.  E4 is connected to pin 8 which is the CART#
signal.  The E3 pad is not soldered to anything which by the way is the E
clock signal.   My guess is after the board was manufactured, a change
needed to be made in the hardware to reflect a change made to the code put
into the mask programmed rom installed in the pak, but that is just
speculation on my part.  No other modifications or differences seem to exist
between my RS-232 pak and yours that I can see.  I probably bought my pak
new, but I honestly can't remember.
Kip

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
Behalf Of John E. Bielak
Sent: Wednesday, April 03, 2013 9:20 PM
To: Coco at maltedmedia.com
Subject: [Coco] RS-232 Pak Back to Stock

I picked up a deluxe RS-232 pak thats somewhat modified that I'm trying to
put back to stock.

The changes:
- The ROM has been cut out
- The trace for pin 4 cartridge edge connector has been cut and there is a
wire going out to an external connecter
- There's a jumper between E1 and E2
- A jumper appears to have been removed from E3 and E4

Obviously,  I need to desolder the old ROM pins, put a socket in, drop in a
4K EPROM (2732?) with the cart image, and then reconnect trace to connector
pin 4, but I don't know what to do with the E1 - E4 jumpers. 
I've Googled around and the only examples I've been able to find are other
modded boards, nothing that appears stock.

-JEB-

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