11 Feb
2015
11 Feb
'15
9:37 p.m.
On 02/11/2015 10:50 PM, Chuck Guzis wrote:
On 02/11/2015 05:47 PM, Jon Elson wrote:
No, the 2250 had all the "smarts" in the computer room, and
sent video down a wire to the
terminal. The terminal had a cheap Zenith TV set in the
housing, the tuner was still there,
as it was needed to complete the line-voltage heater string
which had to add up to 120
V.
The original Beehive was a classic dumb serial terminal. I
think it had no screen addressing, just
scrolled text with line feed, CR and tab. The ASCII
character codes were held in the
serial memory, and the char gen ROM was fast enough to
convert on the fly, I think.
I should still have the drawings around here somewhere.
Jon
On 02/11/2015 01:22 PM, Chuck Guzis wrote:
Hmm, not familiar with that terminal. Was it like the IBM
terminals (2250 IIRC?) that used delay lines for video
memory (i.e. the delay line didn't drive a ROM character
generator, but rather held the generated characters)?
That was the Super Bee, right? 8008 CPU, but I
thought
the memory was
MOS shift-register, not bucket-brigade (which I mostly
associate with
analog applications, such as reverb effects).
No, this predated the super bee. No
CPU at all, just
about 75 TTL ICs,
the clock
drivers and the bucket brigade chips. And, yes, some
versions of them were
capable of analog signals, and used to make reverbs.