Re: Please help identify cards.

[dempson@actrix.gen.nz (David Empson)]

Robert Flossmann <Robert.Flossmann@dillingen.baynet.de> wrote:

> Hi there,
> 
> I recently acquired an AIIe. There are two cards in it, that I don't
> know the use of. Can you help?
> 
> The aux slot contains a short card connected to a cynch socket that
> gives even a poorer picture on my monitor than the built in one.

What is a "cynch" socket?  I assume you mean it is the same as the
composite video connector on the IIe motherboard (similar to an RCA
socket).

Can't help with what this card is.  I can't think of any IIe auxiliary
cards that produce composite video, only RGB.

> Slot 1 contains a short card connected to a 25pin D-sub socket, it has
> n-para2 written on it. I suppose, it's a parallel card. How do I operate
> it?

Sounds like a parallel card, but "n-para2" doesn't help much.  I'd need
more identifying details to be able to guess which brand this is.

> How can I tell if it's an enhanced AIIe?

When you turn the machine on or reboot, look at the title displayed on
the top line.  If it says "Apple ][" then you have the original IIe
ROMs.  If it says "Apple //e" then you have the enhanced IIe ROMs.


This is not a conclusive indication of an enhanced IIe, because someone
might have done a partial upgrade.  To be absolutely sure, you need to
verify that you have a 65C02 processor, and that the computer is able to
display MouseText characters.

> What benefits do I get from the enhancement?

The upgrade consists of four chips:

- The CPU (6502) is replaced with a 65C02.  This has lower power
consumption and additional instructions.

- The two firmware ROMs (CD and EF) are replaced.  These add new
firmware features, including improved 80-column performance, lower case
command support in Applesoft BASIC, some enhancements to the monitor
firmware (e.g. a mini-assembler), and a proper interrupt handler.

- The video ROM is replaced.  The enhanced version includes the
"MouseText" set of characters, replacing one of the two sets of inverse
upper case letters in the alternate character set.

The major advantage of the enhancement is that more software will work
on the machine, as a fair amount of recent software (relatively
speaking) requires an enhanced IIe as the minimum machine.

The only real disadvantage is that some older software stops working or
has display problems, due to using undocumented firmware entry points
(which may have changed in the enhanced firmware), relying on the side
effects of undefined 6502 opcodes (which behave differently in the
65C02), or using the "wrong" uppercase inverse character set in
alternate display mode (causing all uppercase inverse characters to
appear as MouseText, which makes it unreadable).

Two examples that come to mind:

- The original Apple LOGO (its copy protection scheme uses an illegal
instruction in the boot code).  It must be patched to work on an
enhanced IIe, IIc or IIgs.

- The DOS 3.3 version of AppleWriter IIe suffers from the MouseText
display problem.  The ProDOS versions are fine.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand