24 Jan
2014
24 Jan
'14
9:14 a.m.
On 01/24/2014 08:03 AM, Paul Koning wrote:
Almost always that is true. There is at least one
oddball exception:
the 21-bit synchronous output stream for the PLATO terminals. That
consists of a start bit, 19 data bits, and a parity bit. Idling is
done by sending NOP commands, which have all zero in the data bits
(but the standard start and parity bits).
Heh, CDC could be very strange at times. Around 1975, I was assigned
the job of project manager for the STAR-100 remote operator's console.
My job was mostly administrative; I did none of the programming or
design--just made sure that the project came in on time and attended the
(ugh) status meetings.
I remember asking the engineer about using an (at that time) commodity
LSI UART to handle data, but his boss nixed the idea, so the add-on to
the MCU was designed using SSI chips. I never understood why, but it
worked. It also used an oddball data rate--1800 bps., but that was
probably just a compromise based on how much leased-line bandwidth was
considered expendable.
--Chuck