"Michael J. Mahon" <mjmahon@aol.com> wrote in message
CqydnedULOW-gjnYnZ2dnUVZ_tqnnZ2d@comcast.com">news:CqydnedULOW-gjnYnZ2dnUVZ_tqnnZ2d@comcast.com...
There was nothing particularly innovative about attaching a floppy drive
to a microcomputer, but doing the data separation with a PROM and a
shift register combined with software, eschewing the usual integrated
controller chip, was brilliant.
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.
When the first PONG game clone appeared using a single PIC uC
that was quite an event. The original game used much simplier components
but this was an engenious design.
The fact that an 8-pin microcontroller is often now a better overall
solution than a 555 timer doesn't alter the fact that the timer is
a much simpler device, and a much lower level of technology.
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 :)
Just the other day I was thinking about how wonderful the design of
the vacuum tube timing ramp generator called the phantastron was--a
beautiful use of negative feedback before gain was free and negative
feedback was everywhere. And now, only a few old radar engineers
would even know it existed...
Thanks for mentioning it. I've looked it up and sure it is a nice design.
But I think I have an even better example.
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?