13 Oct
1999
13 Oct
'99
12:34 a.m.
The reason the manual says "Use only formatted
RX50 diskettes" is that
formatting the 10 sectors/track on an RX50 is rather critical, and most DEC
machines to which those drives were connected, weren't supplied with
formatting software. Rainbows were, though (I think), and I regularly
format RX50s on other machines.
Two reasons DEC did this. One was they believed the RX50 was to "sloppy"
to format reliably and most of the smaller controllers used with it ran
out of rom and couldn't fit the formatter. Add to that a generally weird
attitude about formatting media in the field.
???? 720K,96tpi,80tracks/side - What was (is) this called? DSQD?
The number of tracks has nothing whatsoever to do with the density! RX50
is SSDD, it just happens to have 10 sectors of 512 bytes per track, and 80
tracks. Your "??? 720K" is DSDD. Yes, some people did call this QD, but
it isn't a different density at all -- the misnomer comes from people who
don't understand what the words mean. Your numbers for 180K, 360K, etc,
assume a particular number and size of sectors, which need not be the case
(ie you can use the same drive and media to make a disk of different
capacity).