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Re: Unusual Paymar adapter

bieling@terra.es wrote:

Michael J. Mahon ha escrito:



Jorge ChB wrote:


Michael J. Mahon <mjmahon@aol.com> wrote:




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?



I had a "Dan Paymar's lowercase adapter", but iirc it was little more
than a ROM that replaced the onboard char. gen. ROM.
This one you've found must be a "deluxe" version or something.
My best guess is that the extra circuitry is there to engage somehow
alternate characters when in inverse or flash modes..?


I also had the single-EPROM "lower case adapter" for my ][+.
This one is quite different.

It could even be an alternate character set...



It may be an LCA-2 ?
There's somebody selling the manual in ebay:
item #8816466656


Though it's a little hard to tell from the photo, this manual reminds me
of the manual for my 1-ROM Lower Case Adapter.

It may well be that the LCA-2 is the single ROM version--an
"improvement" over the "original" 2-ROM version...

-michael

Parallel computing for 8-bit Apple II's!
Home page:  http://members.aol.com/MJMahon/

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