21 Sep
2015
21 Sep
'15
10:35 a.m.
Not CP/M admittedly, but small contemporary
Burroughs machines certainly used cassettes, both
for program and data storage. I wrote several
fairly complex diskless accounting systems using
four cassette drives, one or two card readers and
a line printer (in addition to the console
printer).
Why not; not much different conceptually after all
from early systems using open-reel mag tape, or
even punch(ed) cards.
I feel there are 2 distinct types of cassette system from the
user perspective.
The first is the sort used on 1980s home computers with a
standard or slightly modified (Commodore, Atari) audio
cassette recorder. These needed considerable manual
intervention to position the tape (rewind, fast forward),
select record or play mode, etc. Essentially only useable
for loading/saving programs and sequential files
The second has the tape mechanism under computer control
like the HP9830 (HP9865 add-on drive too), this Burroughs
the PX8, etc. With these you can load particular files, rewrite
files, possibly have a block-structured file system. Often these
units (but not the PX8) used a special tape with a different
coercivity to audio tape.
The second type would seem to be entirely useable for
'business' computing before floppy drives were
available. I am not so sure about the first type :-)
-tony