Re: What is the quintessential Apple II?

["mdj" <mdj.mdj@gmail.com>]

Michael J. Mahon wrote:

> > Of course, if all I had left was a digital input, I'd use the same
> > technique you did, or see other post alternative technique which works
> > a lot better when the sample rate needs to be constant, or even just
> > relatively high.
>
> Analog inputs on microcontrollers have only recently become almost
> universal.  But programmable digital input/outputs have been there
> for as long as microcontrollers, and using an RC delay to convert
> a variable resistance to a variable delay is a standard.

I'd almost forgotten what the older ones were like. The first uC I used
as a regular electronics 'tool' was the PIC16F84 about ten years ago.
These had 3 inputs.

The chip I'm currently playing with, the 18F4550 (PIC) is amazing.
48Mhz, plenty of program memory, plenty of flash and onboard USB.
Incredible little piece of engineering.

I often think while fiddling with this thing: hmm, loads program from
serial device, has core memory, harvard architecture - if they make a
documentary about the PIC they should call it "Honey I shrunk the
minicomputer" ;-)

> And before analog inputs became universal, there were timers that
> would measure the width of an input pulse--a good match to the RC
> trick and with little load on the processor.

That works too :-)

Matt