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Unusual Paymar adapter
- Subject: Unusual Paymar adapter
- From: "Michael J. Mahon" <mjmahon@aol.com>
- Date: Tue, 06 Jun 2006 11:09:46 -0700
- Newsgroups: comp.sys.apple2
- Reply-to: mjmahon@aol.com
- User-agent: Mozilla Thunderbird 1.0 (Windows/20041206)
- Xref: g2news2.google.com comp.sys.apple2:8891
In going through some boxes (!), I found an unusual Dan Paymar adapter.
It is a "daughtercard" that plugs into a ROM socket (probably the
character ROM), and has on top two 24-pin sockets (for other ROMs),
and also two wires about 4" long going to a small socket adapter
having a 16-pin plug on the bottom and a 16-pin socket on top, with
a 14-pin 'LS74 plugged into it.
The daughtercard also has two ICs, a 7404 and a 7410, plus a
decoupling capacitor. The manufacturing date code on the
card is 7639, so this is a *very* early mod.
I'm guessing that the 'LS74 is used to switch between the two
ROMs, but I have no documentation or software.
Does anyone know about this?
-michael
Parallel computing for 8-bit Apple II's!
Home page: http://members.aol.com/MJMahon/
"The wastebasket is our most important design
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