Re: Question about a Sup-R-Mod II de-installation

["Michael J. Mahon" <mjmahon@aol.com>]

Chris Alaimo wrote:
> OK, it is actually a 9334 chip, so I was wrong.  The little board that
> was plugged into the F14 socket had a 9334 chip on it, which I removed
> and placed in the F14 socket, so my ][ is operating quite nicely
> post-supermod.

That must be a very early Sup'R'Mod--later ones had a 4-pin connector
that mated with a 4-pin header on the main board, located just in front
of the video jack.

My guess is that the little board that plugged into (and hosted) the
chip was a "softswitch" to allow the Apple to switch the video from
main board video to 80-column card video--this function is unrelated
to the Sup'R'Mod.  The most popular and best software-supported 80-
column card was the Videx, and it had an optional video softswitch
like you describe.

In fact, using a modulator with an 80-column card is a very bad idea,
since the bandwidth available through an RF link is much less than
that required for sharp 80-column characters.

> I would still like to purchase a 9334 chip so that I can put the
> Sup-R-Mod back together.  I am also in need of a 2716 chip for socket
> E12 and an AY3600 chip for socket E14.  If anyone has these and is
> willing to sell them, please let me know.

From what I can see, the chip at E12 is a 16-pin DIP (74LS153) as
is the chip at E14 (74LS283).

The Monitor/BASIC ROMs are nearby, from F3-F11, but none of those
will take a 2716 without an adapter.

There is no AY3600 on the main board of an Apple ][--but there is
one on the keyboard encoder board.

-michael

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