Re: Apple IIe Mystery Boards

[nparker@cie-2.uoregon.edu (Neil Parker)]

In article <343E69F4.2ABB@terra.cira.colostate.edu> Jeff Lemke
<lemke@terra.cira.colostate.edu> writes:
[text reformatted to fit on 80-column screen]
>Can anybody clue me in on a few interface cards I found?  One board
>says it's a PKASO Interface.  There are 8 rather long wire prongs
>coming out and bent up at a 90-degree angle on the left end, and
>there's a 16-pin connector on the right end.

This is a printer interface card.  I believe it has fancy graphics-
printing firmware built into the firmware.

>Another board has a series of what might be memory chips along with a
>Z80A CPU.  I'm guessing the Z-80 allows you to run CPM programs.  Is
>that correct?

Probably.  If so, you'll need to find a CP/M boot disk in order to get any
use out of the card.  Be careful--each brand of CP/M card needs its own
custom boot disk--boot disks from other manufacturers usually don't work.

>There are a couple other boards that weren't installed in anything.
>They're dated 1979 - of Apple II+ vintage.  They're both in their
>original little boxes, and both put out by California Computer
>Systems.  One is an Arithmetic Processor AP-1, Mod.7811A.  (The HI BYTE
>and LO BYTE chip sockets are empty.)  I'm curious as to what advantages
>this board will provide to a 6502.  How much of a speed advantage would
>it provide?  The other CCS board is an Asynchronous Serial Interface,
>Mod.7710A.  There are 4 baud rate DIP switches on it (B0-B3).  What
>does 'asynchronous' mean for a serial interface?  How would this card
>differ from Apple's Super Serial Card?

For all practical purposes, "asynchronous" means "communicates in the
manner expected by most modems, serial printers, etc."  (If you care about
technical details, "asynchronous" means each character transmitted on the
line comes with its own indication of where the character starts and stops,
in the form of an extra "start bit" at the beginning of the character and
1, 1.5, or 2 "stop bits" at the end of the character.  The opposite of
asynchronous is "synchronous," which means long, multi-byte packets are
transmitted without any indication of where one byte ends and the next
begins--the receiving system has to be able to figure out all by itself how
to stay synchronized with the data.  In the home computer world, almost all
serial communication is asynchronous...the only major synchronous serial
serial protocol I'm aware of is Appletalk.)

I've never used a 7710A serial card, so I'm not familiar with all the ways
the firmware differs from the Super Serial Card, but I can tell you that
they use different hardware...the 7710A has a Motorola 6850 serial chip,
and the Super Serial Card has a 6551.


I'm afraid I know nothing at all about the arithmetic processor card.

             - Neil Parker
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