21 Sep
2014
21 Sep
'14
7:09 p.m.
On 09/21/2014 05:44 PM, Ali wrote:
I've looked through manuals and can't come up
with something definitive:
what is the difference between the 850 and an 851 (or for that matter 800
vs. 801 or 900 vs. 901)? TIA!
The 800 has no support for hard-sectoring (programmable divider for
32,16 or 8 logical sectors) and a index separator (separates the index
pulse from sector pulses--sector pulse output is on a separate pin).
You can turn an 801 into an 800, but not vice-versa.
Same difference between the double-sided 850 and 851.
For many people, this doesn't matter--the floppy controller often
contains the logic to separate index from sector pulses in hard-sectored
media.
One case I ran into was getting a batch of hard-sectored media, but
recorded as soft-sectors. Someone had obviously run into a batch of
hard-sectored media and decided to set the HS mode on their drive and so
made use of the index output only.
--Chuck