Re: Super Serial cd: for IIe slot #3??

[david@wraith.cs.uow.edu.au (David E A Wilson)]

foegelle@sleepy.cc.utexas.edu (Michael Foegelle) writes:
>column card.  Since the control lines for the 80 column card do not use
>the standard I/O range (unless I'm totally mistaken, which I'm sure I'm 
>not.) at $C030-$C03F, there's no reason the computer can't talk to the 
>6551 ACIA on the SSC.

Correct (except that the address range in question is $C0B0..$C0BF).

>Thus something like a terminal program which talks
>straight to the hardware would have no problem here.  However, the firmware
>portion of the SSC which contains all of the program information which is
>normally activated when you do a "PR#1" to start printing, etc, would 
>interfere with the 80 column firmware (actually it may take precedence).

If the SLOTC3ROM softswitch is set then the firmware on the card in slot 3
will be accessable (PR#3 will direct output to it, Pascal will use it as
the console etc). If SLOTC3ROM is not set then the internal 80 column
firmware will be accessable and if you have memory in the Aux slot then
you will have access to 80 columns, otherwise just 40 columns but with the
additional features the 80 col firmware provides.

>Thus, the SSC would have to be hacked to disable the firmware portion of
>the card.  (This probably reduces its usefulness as a printer card since 
>many programs rely on firmware routines.  On the other hand, as a modem
>interface, or for that matter hacking the Datalink to remove firmware
>control and placing it there, it would probably work fine.

No hacking is needed. The //e already supports the ability to disable the
firmware on the card in slot 3. See ProDOS 8 technote #15 for info on
which card will be turned on after booting ProDOS.

NB. Watch out for interrupts on an enhanced //e if you turn off the 80 col
firmware.
-- 
David Wilson				+61 42 213802 voice, +61 42 213262 fax
Dept Comp Sci, Uni of Wollongong	david@cs.uow.edu.au