14 Oct
2009
14 Oct
'09
4:45 p.m.
Hi guys,
Does anyone know what the largest capacity MFM or RLL (i.e.
ST-506/ST-412 type interface) hard disk was? I know the AT drive types
go from 0 to 46 (plus user defined type 47), and the largest of these is
#46: 1224 cyls, 15 heads, 17 secs (152MB). Question is, did anyone
ever make an MFM drive that big, or was that strictly IDE territory?
I know 80MB and 120MB IDE drives existed -- I used to have a Conner
120MB that was an utter pig to make work with any other drive, and I
still have an IBM WDA-L80 80MB IDE drive. Thus far, the largest MFM
drive I've found is the Micropolis 1325 (85.3Mbytes unformatted).
Reason I'm asking is that I'm working on the seek logic for the disc
analyser. At the moment, you can seek 127 cylinders at a time in either
direction (there isn't a track-counter on the hardware, so all seeks are
relative) and I was wondering if there's any point in increasing this
further to accommodate drives with higher track counts.
Cheers,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
4:58 p.m.
On 10/14/09, Al Kossow <aek at bitsavers.org> wrote:
Philip Pemberton wrote:
And, in case you aren't familiar with it, it happened to be known as
the RD54 in the DEC world, so it is *not* an uncommon drive (I have
several).
It worked great with the RQDX3 and in the MicroVAX/VAXstation 2000.
*Much* more robust than the RD53/Micropolis 1325.
-ethan
Hi guys,
Does anyone know what the largest capacity MFM or RLL (i.e.
ST-506/ST-412 type interface) hard disk was?
The Maxtor 2190
5:49 p.m.
Al Kossow wrote:
The Maxtor 2190
TH99 lists that as 1224 cyl, 15 heads, 33 spt, 256 bytes per sector. And
the prize for "biggest MFM disc" goes to....
Also, I wasn't aware that there were any MFM drives that handled
precompensation on-disk. That's useful to know.
You should think about ESDI as well, if you can handle
the data rates.
Maybe, but I need to find a spec for the ESDI interface first.
Wikipedia's entry is decidedly thin on actual information (and Google
just keeps giving me links to the usual scam and keyword-stuffing sites).
It looks like in ESDI, the drive handles all the bit-level encoding and
decoding (so it's about half-way between MFM/RLL "dumb" drives and
SASI/SCSI/ATA "embedded controller" drives). That means the actual
read/write stuff might be easier, but I doubt you'd be able to put both
MFM and ESDI in the same FPGA microcode (the I/Os would be vastly
different). You'd still have to deal with finding bit-sync markers...
Hm. Maybe later.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
7:06 p.m.
Philip Pemberton wrote:
Maybe, but I need to find a spec for the ESDI
interface first.
... 2... 1... and I realise I just stuck my foot in it.
http://bitsavers.org/pdf/micropolis/ESDI_spec_X3.170-90.pdf
(I even had the /pdf/micropolis directory open in a different browser
tab while I was skimming the contents of /pdf/maxtor ...)
I will now bow my head in shame.
Later,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
6:10 p.m.
On Wed, 14 Oct 2009, Al Kossow wrote:
That's what I would have said as well.. Has 1224 cylinders and 15 (or is
it 17) heads.
IIRC, they required the WD2010 controller due to some limitations of the
WD10xx series.
Steve
--
Does anyone
know what the largest capacity MFM or RLL (i.e. ST-506/ST-412
type interface) hard disk was?
The Maxtor 2190 
15 Oct
15 Oct
12:02 p.m.
On 14 Oct 2009 at 18:10, Steven Hirsch wrote:
IIRC, they required the WD2010 controller due to some
limitations of
the WD10xx series.
It was a BIOS software limitation, pure and simple. The "standard"
INT 13H BIOS interface calls for a 10-sector cylinder number (8 bits
in CH and 2 "borrowed" bits from the sector number register in CL).
Some late BIOSes (such as those on the WD1006VSRx) expanded the
cylinder number by borrowing some bits from the head number in
register DH.
If you were content to throw away (or supply your own driver for he
extra) 200 cylinders, any MFM controller could be used.
I'm still suprised that everyone checked in with the Maxtor and not
the earlier Priam 519, which was a very good drive.
--Chuck
1:19 p.m.
On 15 Oct 2009 at 13:00, Sridhar Ayengar wrote:
Chuck Guzis wrote:
A quick web check shows that they're still being stocked by some
sellers (as well as their Atasi rebrandings), so for those not able
to find the Maxtors, the Priams may well be an equivalent
substitution.
(I've got two of the buggers; a little noisy when seeking, but
they've always been that way).
--Chuck
I'm still suprised that everyone checked in
with the Maxtor and not
the earlier Priam 519, which was a very good drive.
I would have, but I've never actually seen one.
16 Oct
16 Oct
7:40 a.m.
On Thu, 15 Oct 2009, Chuck Guzis wrote:
On 14 Oct 2009 at 18:10, Steven Hirsch wrote:
Hmm. There was a limitation somewhere that the WD20xx series corrected.
Number of heads, perhaps? Or am I confusing things totally?
--
IIRC, they required the WD2010 controller due to
some limitations of
the WD10xx series.
It was a BIOS software limitation, pure and simple. The "standard"
INT 13H BIOS interface calls for a 10-sector cylinder number (8 bits
in CH and 2 "borrowed" bits from the sector number register in CL).
Some late BIOSes (such as those on the WD1006VSRx) expanded the
cylinder number by borrowing some bits from the head number in
register DH.
2:20 p.m.
On 16 Oct 2009 at 7:40, Steven Hirsch wrote:
Hmm. There was a limitation somewhere that the WD20xx
series
corrected. Number of heads, perhaps? Or am I confusing things
totally?
I'm not certain--I do know that the entire drive is physically
accessible using a garden-variety WD AT-style controller, but that
BIOS support for the extra 200 cylinders was lacking in most
adapters. If we get sufficiently desperate, I can haul one out and
do a look-see. It should still have whatever data I last left there
20 or so years ago.
--Chuck
5:43 p.m.
On 14 Oct 2009 at 16:59, Sridhar Ayengar wrote:
Maxtor 2190. 155MB
Also the Priam/Atasi 519 and Storage Dimensions AT-160, The
1224C/15H seemed to be the top of the range. I used my 2190s and
519s with WD 1006VSR2 controllers to gain yet 50% more. I never got
a chance to try one with a Perstor ARLL controller.
At those capacities, SCSI and MFM were pretty close in pricing--and
SCSI could go much larger. SCSI had the advantage of being faster.
--Chuck
4:55 p.m.
cctalk-bounces at classiccmp.org wrote:
Hi guys,
Does anyone know what the largest capacity MFM or RLL (i.e.
ST-506/ST-412 type interface) hard disk was? I know the AT
drive types
go from 0 to 46 (plus user defined type 47), and the largest
of these is
#46: 1224 cyls, 15 heads, 17 secs (152MB). Question is, did anyone
ever make an MFM drive that big, or was that strictly IDE territory?
The DEC RD54 (Maxtor XT-2190) was 159MB or so. I once had a brace of
them on a PC.
Antonio
5:16 p.m.
On Wed, Oct 14, 2009 at 4:55 PM, <arcarlini at iee.org> wrote:
The DEC RD54 (Maxtor XT-2190) was 159MB or so. I once
had a brace of
them on a PC.
I had a PCs or two with a Micropolis 1325, but I'd already converted
over to Adaptec SCSI controllers and embedded SCSI drives (frequently
surplus/castoffs from a Sun environment) rather than go above about
60MB on MFM/ST412. I didn't get an IDE drive for anything until after
1992 - it was all small MFM and large(er) SCSI for my sub-32-bit
environments. Any "large" disks ended up going on VAXen and PDP-11s.
The idea of a PC with "a brace" of FH 5.25" drives on it is somewhat
daunting. The closest thing I can imagine to it is a fully-loaded
BA123, and I've never *seen* one of those above two or three spindles.
-ethan
5:47 p.m.
Ethan wrote:
On Wed, Oct 14, 2009 at 4:55 PM, <arcarlini at
iee.org> wrote:
They were discarded at work and my (286) PC at the time had
A 20MB drive in there. So I was quite grateful :-)
The DEC RD54 (Maxtor XT-2190) was 159MB or so. I
once had a brace of
them on a PC.
I had a PCs or two with a Micropolis 1325, but I'd already
converted over to Adaptec SCSI controllers and embedded SCSI
drives (frequently surplus/castoffs from a Sun environment)
rather than go above about 60MB on MFM/ST412. I didn't get
an IDE drive for anything until after 1992 - it was all small
MFM and large(er) SCSI for my sub-32-bit environments. Any
"large" disks ended up going on VAXen and PDP-11s. The idea of a PC with "a brace" of FH
5.25" drives on it is
somewhat daunting.
Imagine a desktop case with a "flip-top" lid (easily opened,
just press two buttons, one on each side. One RD54 sat
neatly under the 5.25" floppy drive (where two PC HDs would
normally go). The other RD54 sat upside down _on top_ of the
floppy drive ... there was no room in the case, you see ...
Quite scary that I have an 8GB flash disk that goes to and from
work daily these days! Times change. Luckily we don't have to.
Antonio
7:01 p.m.
;)
I'll have to show my BA123 uVAXII with 2 RZ56, RD54(maxtor 150mb),
and the RD52 (Quantum D540 31mb) it has both RQDX3 and CMT SCSI
for a whopping 1.4GB of storage on 4 full height drives.
Thats about 180 Watts of drives alone.
The drive bay is only 4 drives
slot nominally used for RX50/TK50 has a RZ56 in it.
I also have a few BA42 storage boxes, those hold two RZ56 or any
full height 5.25" drives and weigh a bit.
Since I have an abundance of RZ56s and RD52s I use them as backup
(image of the drive) rather than slower TK50.
My 11/73 has 4 RD52s, RX33, RX02 and RL01 in one rack.
I'm used to big drives like RA8x and RA9x so these are somewhat small.
Allison
Ethan Dicks wrote:
On Wed, Oct 14, 2009 at 4:55 PM, <arcarlini at
iee.org> wrote:
The DEC RD54 (Maxtor XT-2190) was 159MB or so. I
once had a brace of
them on a PC.
I had a PCs or two with a Micropolis 1325, but I'd already converted
over to Adaptec SCSI controllers and embedded SCSI drives (frequently
surplus/castoffs from a Sun environment) rather than go above about
60MB on MFM/ST412. I didn't get an IDE drive for anything until after
1992 - it was all small MFM and large(er) SCSI for my sub-32-bit
environments. Any "large" disks ended up going on VAXen and PDP-11s.
The idea of a PC with "a brace" of FH 5.25" drives on it is somewhat
daunting. The closest thing I can imagine to it is a fully-loaded
BA123, and I've never *seen* one of those above two or three spindles.
-ethan
18 Oct
18 Oct
9:04 p.m.
Ethan Dicks wrote:
On Wed, Oct 14, 2009 at 4:55 PM, <arcarlini at
iee.org> wrote:
Starting around 1997, I was using a Pentium 166 MMX with 2 * Hitachi 1.5
GB DK516-15
ESDI FH 5.25" hard drives as my storage devices. They were my C: and D:
drives with the
D: drive serving ONLY as a backup. I still have a few around which were
also used on a
BA123 running RT-11 on a PDP-11/83 with a Sigma RQD11-EC ESDI Qbus
controller.
I stopped using them for the PC around 2002 when I switched to a Pentium
III with 3.5 " drives.
These were 3 * Maxtor D540X-4X of 40 GB each. Unfortunately, the
Maxtor drives failed
around 2006 when I switched to 160 GB drives.
On the other hand, I still occasionally use the Hitachi DK516-15 ESDI
drives on the BA123.
It would seem that except for the RD53 drives, all of the old MFM and
ESDI drives that I used
with a DEC system still work. But the IDE drives, especially the Maxtor
drives, lasted only 3 years.
Sincerely yours,
Jerome Fine
The DEC RD54 (Maxtor XT-2190) was 159MB or so. I
once had a brace of
them on a PC.
I had a PCs or two with a Micropolis 1325, but I'd already converted
over to Adaptec SCSI controllers and embedded SCSI drives (frequently
surplus/castoffs from a Sun environment) rather than go above about
60MB on MFM/ST412. I didn't get an IDE drive for anything until after
1992 - it was all small MFM and large(er) SCSI for my sub-32-bit
environments. Any "large" disks ended up going on VAXen and PDP-11s.
The idea of a PC with "a brace" of FH 5.25" drives on it is somewhat
daunting. The closest thing I can imagine to it is a fully-loaded
BA123, and I've never *seen* one of those above two or three spindles.
14 Oct
14 Oct
7:07 p.m.
Antonio,
I still have working RD54s (maxtors) (151mb DEC RQDX3 formatted).
For MFM 160mb was about the largest. For RLL you could get
to about 200mb. EDSI was the 200mb and larger interface
for the largest of the 5.25" non integrated drives.
SCSI started with drives in the 20MB range but I have
SCSI-1 drives like RZ56s (5.25" full height)
at 670MB and a RZ58 (5.25" full height) at a 1.3GB.
Allison
arcarlini at iee.org wrote:
cctalk-bounces at classiccmp.org wrote:
Hi guys,
Does anyone know what the largest capacity MFM or RLL (i.e.
ST-506/ST-412 type interface) hard disk was? I know the AT
drive types
go from 0 to 46 (plus user defined type 47), and the largest
of these is
#46: 1224 cyls, 15 heads, 17 secs (152MB). Question is, did anyone
ever make an MFM drive that big, or was that strictly IDE territory?
The DEC RD54 (Maxtor XT-2190) was 159MB or so. I once had a brace of
them on a PC.
Antonio
6:18 p.m.
On 14/10/2009 21:45, Philip Pemberton wrote:
Hi guys,
Does anyone know what the largest capacity MFM or RLL (i.e.
ST-506/ST-412 type interface) hard disk was? I know the AT drive types
go from 0 to 46 (plus user defined type 47), and the largest of these is
#46: 1224 cyls, 15 heads, 17 secs (152MB). Question is, did anyone ever
make an MFM drive that big, or was that strictly IDE territory?
Maxtor did - the XT-2190 is 151MB (formatted). DEC sold them as RD54
drives.
--
Pete Peter Turnbull
Network Manager
University of York
5364
days inactive
5369
days old
20 comments
11 participants
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aek＠bitsavers.org -
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arcarlini＠iee.org -
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ethan.dicks＠gmail.com -
jhfinedp3k＠compsys.to -
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