Re: What is the quintessential Apple II?

[heuser.marcus@freenet.de]

Michael J. Mahon schrieb:
> Alex Freed wrote:
> >
> > Absolutely! Probably the best "hack" in the original sense of all. But my
> > point is that the driving force behind the design is not "how to make it
> > using the simpliest set of components". Instead it is "how to make it using
> > the inexpensive off-the-shelf stuff". Now if the dedicated FD controllers
> > were
> > a dime a dosen and one had been used in A2 nobody would be talking
> > about the design 20 years later, that's a given. But then if a disk
> > controller
> > is build with 50 low scale ICs is also nothing to write home about.

>From what I've read Woz's designs were governed by board space
and accessibility of parts. I'm pretty sure that if a one chip disk
controller and the Disk II would've been readily available at 1977
he would've incorporated the chip on-bard. But they weren't and
though a PROM may be simple compared to other devices it is
already something quite complex - you have to program it.
And the command sequencing and stuff isn't something Joe
Hacker cooks up in an instant. Like Michael said: It's brilliant.

> > True, but does it bring you any browny points? If an 8-pin microcontroller
> > costs the same as a 555, should you try using a 555 with a cap and a
> > couple of resistors to say blink a LED? The 8-pin uC will do it even better
> > and the design will be more flexible. Want to change the rate, just write
> > a different constant into FLASH. No caps to change :)

A more complex design _can_ introduce complex errors.
Sometimes its better to get a bit more down to earth, I think.
On the other hand a 555 may be more scarce than the multitude
of programmable chips - if one listens to this and other newsgroups...
;-)


> > Before integrated counters and 7-segment LEDs there was a wonderful device.
> > I can't remember what it was called but I saw them in some very old
> > equipment
> > in the lab.
> >
> > A tube filled with inert gas and 10 sets of electrodes in a circular
> > configuration.
> > A glorified neon lamp.
> > At reset the "0" electrode will light up. After an input pulse the discharge
> > will move to the next electrode. After 10 pulses it will be back at
> > the "0" electrode and generate an output pulse.
> >
> > So with nothing but glass and wires it was both a decade counter and a
> > display!
> > Anyone old enough to remember those?
>
> I not only remember them--I *used* them and I *have* one!
>
> The name escapes me at the moment..."dekatron" comes to mind...

A "nixie tube"?

Also:
Regarding the Zip Chip: Yes, it's quite a bigger gun than the original
6502.
But on the other hand it may be the smartest accelerator for the Apple
II
series (if you disregard the Rocket Chip ;-): It uses less space and
parts.

bye
Marcus