[IBBM 5150 cassette port]
The tech Ref had the pinout
Unfortuantely not everybody bought the TechRef.....
Some later RS cables switched from a metal cylindrical shield to a plastic
collar. Breaking off that collar worked, but then you had to be CAREFUL.
The only time I've seen an all-plastic plug on the Radio Shack cable is
the one that came with my first (early) Model 1. That DIN plug locked in
place, you had to pull abc kthe collar to release it. All later cables
(the ones that cabe with later machines, with the EI, with cassette
recorders [1]) have ahd conventional metal-shell plugs.
AFAIK the DIN socket used on the IBM 5150 is the same part as the one
used on a TRS-80 Model 1. Not just a 5 pin type A DIN socket, but the
exact asme PCB mounting part. So unless the plug body fould the PC case
or something, any cable that fits a TRS80 Model 1 will fit an IBM 5150.
[1] At some point Radio Shcak stopped includign the cassette cable with
the machine and bundled it with some of their audio cassette recorders
instead (the 'CCR' -- Computer Cassette Recorder -- range IIRC). You
could still buy the cable separately, but most shops over here didn't
keep it in stock, it had to be ordered.
It was marketing, pure and simple. If you bought a computer and the
cable was included you could buy your cassette recorder anywhere. If you
had to order the cable then a lot of people would pay the extra to get
the recorder+cable there and then....
-tony