Apple II hardware design

From: A.R. Duell <>
Date: Mon Jun 23 09:13:16 1997

> On Sun, 22 Jun 1997, A.R. Duell wrote:
> > This is true, but if you want to do strange things with PC (or any other)
> > hardware then design the card you need. It's not that hard, and it won't
> > affect the machine's performance in other areas.
> But its much faster and easier to do it with software. One of the

Maybe for you. I find it a lot easier to solder up a card (which has a
good chance of working first or second time...) than to write and debug
software. In all my recent projects the hardware (quite complex hardware
- 10's of chips) has taken a lot less time than the (minimal) software.

> things that made the Apple so nice was that it was an excellent
> prototyping machine. You had all sorts of inputs and outputs with which
> to play with. You didn't need to spend time designing an interface card,
> the Apple was experimenter ready! Just add software.

The standard I/O (on the games port) consisted of (IIRC) a few
resitor-reading ADCs, a few single-bit inputs and a few outputs. Not a lot
IMHO. The BBC micro had 8 I/O lines, another 8 outputs if you didn't use
the printer port, handshake lines for all those, 4 ADC channels (10 bit, I
think) _and_ a system bus with a couple of decoded chip select signals on
it. That's what I call an experimenter's machine.

And is it that hard to design an address decoder? It's one chip these
days, probably 2 or 3 at the time the Apple 2 was 'current'

> Sam

The gates in my computer are AND,OR and NOT, not Bill
Received on Mon Jun 23 1997 - 09:13:16 BST

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