From: Jon Elson
the /20 was intended for very specific uses in 360
shops, and maybe as
an entry-level "foot in the door" to move totally tab card shops into
the 360 family. The only /20s I ever saw were used as offline spool
printers and card readers in large 360 shops.
I interned at IBM Bermuda, and they had a 360/20 as their main service bureau
machine; it had (IIRC) a card reader/punch, 4 tape drives, and a 4301
printer. When I got there, they had just gotten in a System 3 (two
single-platter hard drives, a 4301 printer, and I'm not sure what else) to
replace it.
Noel