1 Aug
2013
1 Aug
'13
11:53 a.m.
And as far as I know, there was no official IBM
explanation of where
to get a suitable cable. As mentioned earlier in this thread, the
salesmen at ComputerLand and such places generally would tell you to
go to Radio Shack and buy the TRS-80 cable (p/n 26-1207), but I don't
think IBM ever officially suggested such a thing.
So what did IBM expect you to do?
The 5150 was sold as a cassette-only machine -- the disk drives were
optional. As others have mentioned, the pinout of the cassette connector
was in the TechRef, but not, AFAIK, in any docuemtnation supplied with
the machine. And IBM never sold a suitable cable for the 5150 (they did,
I think, for the PCjr, but that used a 3*2 pin rectangular connector, not
a DIN plug).
What happened if you bought a bare IBM5150 and contacted IBM's support
service to ask how to link it to ta cassette recorder?
Another point : Since IBM picked a 'type A' (180 degree) 5 pin DIN socket
for the casette port so you could use the Radio Shack cable, why did they
use the same connector for the keyboard. Why not a 5 pin type B (240
degree) DIN socket there, which was originally designed ot be sued where
it was desirable to have a socket a normal audio cable would not plug in
to.
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... :-)
-tony