2 Aug
2013
2 Aug
'13
1:35 p.m.
[Identical connectors for keyboard and cassette on the 5150]
But, in this case, it worked! Whew!
And thus is born "Industry standard cassette cable"
Over here, a scdond de-facto standed (started by Acorn, but used
elswhere) was to use a 7 pin DIN socket for cassette. Pins 1-5 wire wired
as for an audio connector, so a normal 5 pin audio lead would fit and
work, albeit without motor control. Motor control, of course, was on pins
6 and 7 (not,e the pins are numbered 6 1 4 2 5 3 7 going round the
connnector). There must be others too....
-tony
They used two identical connectors for vastly
different purposes, because
Radio Shack had done the same with THREE connectors.
Yes.... I have a model 1...
I wonder why Radio Shack did that.
Audio DIN plugs seem ot fint ito several families :
3, 5A, 7, 8A
4
5B, 6
5C
8B
Where : 5A is the normal (180 degree) one, 5B is the 240 degree one (e.g.
an original CoCo Joystick plug), 8A is the 7 pin with an extra pin in the
middle, 8B is the one with the outer pins not all in the same arc (M100
modem socket?). 5C is the quincunical one, like a BBC micro serial port
which cab be plugged in either way up.
Actually, there's a second version of the 4 pin with a switching spigot,
adn a simular 2 pin one (I do not mean the loudspeaker plug). But those
are almost never seen
Witing a family, a plug will fit into a socket with the same number of
pmre contacts.
My view is that the TRS-80 M1 should ahev used the 5A conenctor for the
cassette (as they did), a 5B for the PSU input and say a 4 pin one for
the video. All were easy to get when the M1 was being designed and made,
and they will not fit into each other's sockets.
That let them show the world that they were so big
that they had no
intention of learning from somebody else's mistakes.
Indeed :-(
When my
employer purchased on on the first day of availability, we
didn't even think to ask. We noticed that the connector was the same
as the TRS-80, so we tried a cable we already had, and were pleasantly
surprised that it worked.
This is the sort of attitude which ends up giving
Centronics printers
RS232 levels using PC printer cables... :-)