old terminals...

[jim]

Jules Richardson wrote:

> Richard wrote:
>
>> In article <45F86F35.5080107 at yahoo.co.uk>,
>>     Jules Richardson <julesrichardsonuk at yahoo.co.uk>  writes:
>>
>> <snip>
>> The weirder terminals don't use a CPU at all.  They use SSI/MSI TTL
>> logic.
>
>
> That's what I was wondering. Although I suppose that providing they 
> have a design that can be coaxed into the same architecture as a 
> typical terminal, then it doesn't matter as a box can be drawn around 
> the bit that "looks" like a CPU.

The Microdata Prism was designed around a "cpu" which used only one 
74181.  This actually
was enough to emulate the Adds cursor control the copied.  There was 
very little else in the
way of features that required other than counters.

It had a processor tank running 24 bit wide firmware to handle the 
keyboard, and screen
functions as need be.  I don't think it had more than 32 firmware words 
however.

The Adds 580 logic was designed around the display, and I don't know 
that it had
a cpu per se in the design.

Others in the "no cpu" vein would be the hazeltine terminals, with core 
display
memory, but I never had the info to know what those had as logic.

These all used nothing much more exotic than proms and the ALU at the
high end AFIK.
Jim