Re: Digital Research Z80 "Gold Card"

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

Sean Fahey wrote:
> Well, this is off and on topic... I'm curious about what the draw is with CP/M on the Apple II. The library (afaik) isn't very large and interoperability with other Z80 machines of the era is severely limited if not crippling because the Apple II's disk format. Yet, there is seemingly no lack of Z80 cards out there, and at least a dozen companies made their own card(s) back in the day. So... it was a popular accessory -- but was it over-hyped?
>
> I realize the irony, coming from an Apple II enthusiast such as myself asking this, but why is CP/M on the Apple II so interesting?
>
> I'm not immune btw, I have a small collection of different boards but I'm not using them. Whenever I crack open a new (to me) machine and find a Z80, I'm a little surprised. I assume the original owner used it for Wordstar or something similar. More often than not, the Z80 comes as part of a system but it's been removed and replaced with something else.
>
> If anyone wants to discuss why CP/M intrigues them so much, I'd enjoy reading what you have to say on the matter.

In my case, the draw was certain programs available for the CP/M that
were not available (to me) for the Apple--like Wordstar and muMath.
(I later found out that there _was_ an Apple version of muMath.)

The Apple II with a Z80 card was the most widely available CP/M
platform, perhaps because of the Apple's well-developed market
infrastructure and its convenient design.

The S-100 machines which preceded the Apple II were much less
"consumer-friendly" than the Apple II, and were more likely
to be used by early hobbyists or small businesses supported
by that ecosystem.

To address the interoperability question you raised, many
CP/M machines had their own proprietary disk formats, and the
standard fallback for data interchange was serial ports.  The
large installed base of Apple II CP/M machines pretty much
ensured that programs would be available in Apple disk format.

A business choosing a CP/M-based solution would generally adopt
a single type of platform and replicate it to achieve the needed
media interchangeability--often with 8" floppies, since data
capacity was a big issue for a business.

Adopting the Apple II as a CP/M platform resulted in a much more
compact and affordable CP/M solution for a small office, with an
integrated keyboard.  Of course, as the 1980s progressed, CP/M
became more of a legacy solution, and its users typically "graduated"
to PCDOS/MSDOS, which had substantial similarities.

I "missed" the CP/M wave of early personal computing, but I'm sure
there are participants here who remember it vividly.  ;-)

-michael

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Home page:  http://home.comcast.net/~mjmahon/

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