Re: Apple ][+ Z-Card

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

In article <1466945698-960426021735@rook.wa.com>,
Steve Townsend <steve.townsend@rook.wa.com> wrote:
>     
>     When attempting to boot some programs, we got a
> message saying that this program could not be run without a
> Z-80 Card installed.  As luck would have it, I had one laying
> around from a parts deal I made a year ago, so we put it into
> slot 3.  It worked.  Now he can run some programs that he
> could not run previously.
>     
>     What did we do?  What IS a Z-Card?  Why is it
> necessary?

A Z-80 card is a coprocessor card containing a Z-80 microprocessor.
It is required if you want to run any CP/M software on an Apple II.
(CP/M requires an 8080, 8085 or Z-80 processor, and a fair amount of
software will only work with the Z-80).

The Apple II implemenatations of CP/M use a hybrid system, in which
the disk initially boots using code for the Apple II's main processor
(6502).  This code then locates the Z-80 card, and downloads the CP/M
operating system into the card (or into the Apple II's own memory if
the card doesn't have any RAM of its own).  Control is then
transferred to the Z-80 processor, which takes over the boot process.

There are probably differences between CP/M implementations on the
Apple II for various different Z-80 cards, so you are lucky that you
had the right card.

> By installing the Z-Card, did we eliminate some programs that he
> might want to use someday?

Not likely.  Any program which doesn't require a Z-80 card will just
ignore it.

> Is it installed properly? We did not try any slot other than slot 3.

I'd suggest using slot 4, if it is not already used.  Some programs
expect slot 3 to be used for an 80-column card, and slot 4 is more
commonly used for a Z-80 card.

> Is there anything else that we should do to make his ][+ more
> useful? 

Add an 80-column card, make sure it has a "language card" (16K RAM
card) in slot zero.  This will maximise the software that is useable on
the machine.

He might be better off by getting hold of a cheap Apple IIe, because
there is a LOT of software which requires at least a IIe.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand