21 Sep
2014
21 Sep
'14
5:44 p.m.
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!
-Ali
21 Sep
21 Sep
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
22 Sep
22 Sep
10:38 a.m.
Many of the old 800's have the unpopulated space for the
sector pulse circuit. It is just a matter of sticking the parts in
and adjusting the pots.
Dwight
Date: Sun, 21 Sep 2014 19:09:33 -0700
From: cclist at sydex.com
To:
Subject: Re: Shugart 850 vs. 851
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
1:53 p.m.
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 xx1 models incldue the extra circuitry (monostable and a few gates,
absically) to handle hard sectored disks (and output the correct secotr
and index pulses). xx) models don't
For use with a PC you want soft sectoring anyway. The extra logic on an
xx1 can be disabled (jumpers on the drive PCB) so either will work for you.
-tony
3:22 p.m.
Thanks everyone for the info. I will keep my eye out for 85x in that case. I
may also have a line on a couple of drives locally for cheap. Would be great
if it happens.
-Ali
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Tony Duell
Sent: Monday, September 22, 2014 1:54 PM
To: cctalk at classiccmp.org
Subject: Re: Shugart 850 vs. 851
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 xx1 models incldue the extra circuitry (monostable and a few gates,
absically) to handle hard sectored disks (and output the correct secotr and
index pulses). xx) models don't
For use with a PC you want soft sectoring anyway. The extra logic on an
xx1 can be disabled (jumpers on the drive PCB) so either will work for you.
-tony
3745
days inactive
3745
days old
4 comments
4 participants
participants (4)
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