On Tue, 23 Jan 2001, Barry Gershenfeld wrote:

> >        You ever look inside one of those things? A huge board with little 14
> >and 16 pin small scale chips. I think the biggest chip on it was a 40 pin
> >UART. I had the service manual on it. They had built their own processor
> >out of all these small scale chips, then executed code to make it a
> >terminal.  The stuff people went through before microprocessors!!!
> >
> >Harold
>
> I used to repair the next generation.  Same setup but there was
> an 8008 inside.  All the video memory functions and whatnot
> were way too fast for the processor.  All the processor got
> to do was make the terminal "smart" things--define fields,
> transmit a screen, in effect, an application running on
> top of all that hardware.  Even the UART function was done
> with discrete logic.
>
> These things emulated a VT52 and though I never saw the inside
> of a real VT52 I'd guess they were designed like that, too.

My first was a dumb terminal removed from service as an airline
reservation terminal around 1980, I don't even remember who made it.
Parallel interface to the system, the video memory used (if I recall
correctly) Mostek or some such 80-bit shift registers. Lots of 'em.  All
SSI, four roughly 8x10 boards in a cage.  I intercepted the 8-bit parallel
+ strobe connection from the ASCII keyboard (remember those?) to drop in
my wire-wrapped, scratch built board -- 8080, 2K EPROM, and 8K of 2114
static RAM.  Wrote the monitor and hand assembled it (no access to a
system with an assembler!). I was in the Army at the time, and the whole
mess was stolen in transit from Korea before I got an EPROM burner built
so I never got to actually use it. I could verify all the hardware was
working, but never actually got to play with it.  Still miss that pile of
stuff to this day.

Dale
(man, is this getting pathetic or what?)
---
The most exciting phrase to hear in science, the one that heralds new
discoveries, is not "Eureka!" (I found it!) but "That's funny ..."
                -- Isaac Asimov

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