14 Jan
2011
14 Jan
'11
11:14 a.m.
On 1/13/11 3:57 PM, Tony Duell wrote:
Ah, yes. :-) I'm still fascinated by that setup after all these
years...My first exposures to serial<->parallel conversion were the
AY-5-1013 and the wonderful Z80 SIO.
My introduction to serial<->parallel conmversion was the ASR33 itself.
And the first thing I learnt was that transmission as a lot easier than
reception ;-). This is true however you do it (for example it's a lot
easier to bit-bang a serial data output than a serial data input).
The ASR33 transmitter looks slightly odd to British eyes. The Creeds have
one transmitter contact that is toggled one way or the otehr mechancially
for each bit -- that is there is a lever in the keyboard or reader that
actually represnets the bitstream in real time, it then operates the
switch. Some of the Creed readers have a sproket to move the tape that's
drtietly driven by the motore (the tape doesn't stop and start for each
character as it does in an ASR33) with the row of sense pins ('peckers'
in Creed's terminologu) in a slanting line across the tape. They are
lifted one at a time by a camshaft inside, sensing the holes in each
track one after the other.
-tony
Mine
has an induction motor. There are contacts in the "hardware
UART", of course, but is there enough current flowing through that
You mean the 'mechanical UAT' :-). There are no contacts in the receiver
section.