Re: Computing Editorial (please read)

[Holger Petersen <hp@kbbs.org>]

CBFalconer <cbfalconer@yahoo.com> writes:


>Not initially.  The first 5.25 jobs only held about 80-90k, while
>the bog-standard 8" held about 250k.  Then dd and double sided
>pushed those levels up by about 4.  The next change was to qd/hd,
>which didn't get applied to 8" because they had become obsolete,

I still remember the first Micropolis Ad for "Quad Density".
They used 77 tracks on 5.25 Media wher others at taht time used 40.

=-=

Has anybody an idea about the use of those Pins on an IBM 2.88-Drive,
which are "Ground" on all other 'Shugart'-Cables? My drive does not
have any power-Pin, so I suppose that there is '+5Volt' on some and
perhaps '+12Volt" on others?

I want to interface it to my assortment of other drives[*] on my CP/M-
system.

I have a small 'cicuit' consisting of a single 74154 which uses the
original four drive-select lines as ist's input and I take groups of
4 og its output as new drive-select Lines to one of three flat cables
to the real drives.

asking for help, Holger


[*] 2 NEC 8inch

    one TEAC B  40 Track 5.25 inch DS
    one TEAC F  80 Track 5.25 inch DS
    one Micropolis 77 track 5.25 inch single sided

    one 40 track 3.5 inch DS
    one 80 track 3.5 inch DS
    one 40 track 3.0 inch SS (like Amsrad, Joyce etc)

I am missing:
   an 3.0 Joyce 80 track DS
   an 5.25 Micropolis DS
   some strange 3.2 or 2.8 inch drive...