1 Feb
2014
1 Feb
'14
12:03 p.m.
Hello all,
I recently picked up an NEC PowerMate SX Plus from eBay. Have been
looking
for one for years, so I jumped at the opportunity. The machine has no
hard
drive at all, and 5.25" (1.2MB) and 3.5" (1.44MB) floppy drives,
configured
as drives A and B, respectively, connected to an ISA FDC that also
includes
an IDE controller. Bought an IDE-to-SD board and a 256MB SD card to use
as a
hard drive.
The difficulty is that this is one of those wonky beasts from the very
late
1980s that requires a DOS-based utility in order to access the BIOS
settings,
which I must do in order to configure the cylinders/heads/sectors for
the SD
card. I have downloaded all of the PowerMate utilities from NEC's FTP
site,
per this thread:
http://www.vintage-computer.com/vcforum/showthread.php?26016-NEC-Powermate-…,
but this machine can only boot from the 5.25" drive. I have plenty of
DSHD
5.25" media (brand new) upon which to write an MS-DOS boot floppy, but
the only other
machine I have whose BIOS claims to support 5.25" drives will neither
read
nor write 5.25" media in any of the three drives I've tried, claiming
that
track 0 is bad, or giving me a general failure error. Swapping the
5.25" and
3.5" drives in the NEC is out, since I would again need to get to the
BIOS
settings in order to make it all work.
Not having the budget at the moment in order to buy more machines, I'm
wondering if any of the people on this list have any suggestions, or
would
perhaps be willing to write such a boot floppy for me, if compensated
for
shipping and cost of media.
Thanks in advance,
JPW
1 Feb
1 Feb
12:28 p.m.
On 02/01/2014 12:03 PM, John P. Willis wrote:
but this machine can only boot from the 5.25"
drive. I have plenty of
DSHD 5.25" media (brand new) upon which to write an MS-DOS boot
floppy, but the only other machine I have whose BIOS claims to
support 5.25" drives will neither read nor write 5.25" media in any
of the three drives I've tried, claiming that track 0 is bad, or
giving me a general failure error. Swapping the 5.25" and 3.5" drives
in the NEC is out, since I would again need to get to the BIOS
settings in order to make it all work.
Have you tried DSDD ("360K") media? Unlike its 3.5" siblings, there is
quite a bit of difference magnetically speaking between the DD and HD
media. That is, you can't reliably (if at all) format one as the other.
--Chuck
12:44 p.m.
On Sat, 1 Feb 2014, Chuck Guzis wrote:
Have you tried DSDD ("360K") media? Unlike
its 3.5" siblings, there is
quite a bit of difference magnetically speaking between the DD and HD
media. That is, you can't reliably (if at all) format one as the other.
Years ago, I encountered an amusing oddity, . . .
trying to use "HD" media as "DD" (due to a purchasing agent sleeping
with
a supplier, and giving us Roytype [presumably HD] media, instead of the
Verbatin Datalife DD that we ordered), would sometimes seem to work, but
within minutes/hours/days, the recorded content (including formatting, of
course) was GONE.
1:25 p.m.
On 02/01/2014 12:44 PM, Fred Cisin wrote:
Years ago, I encountered an amusing oddity, . . .
trying to use "HD" media as "DD" (due to a purchasing agent sleeping
with
a supplier, and giving us Roytype [presumably HD] media, instead of the
Verbatin Datalife DD that we ordered), would sometimes seem to work, but
within minutes/hours/days, the recorded content (including formatting, of
course) was GONE.
Several years ago, I had the task of retrieving content from a few
hundred Kaypro 10 floppies. Things went swimmingly until I ran into a
stretch of 3M DSHD floppies. My heart sank as I inserted the first one
and tried to read it--and succeeded. The remainder of the "stretch" of
HD floppies all read fine--they hadn't been touched for at least 10 years.
Some days, you get lucky.
--Chuck
2:46 p.m.
Have you tried DSDD ("360K") media? Unlike
its 3.5" siblings, there
is quite a bit of difference magnetically speaking between the DD and
HD media. That is, you can't reliably (if at all) format one as the
other.
--Chuck
I have not tried any DSDD media. I don't have any at the moment, and
all
my drives are DSHD... not sure if the NEC utilities would even fit on a
boot floppy of that size anyway.
IIRC, there were differences in track spacing--or something to that
effect--
rendering writes to 360K media in 1.2M drives (or was it vice versa?)
problematic.
4:06 p.m.
On 02/01/2014 02:46 PM, John P. Willis wrote:
I have not tried any DSDD media. I don't have any
at the moment, and
all my drives are DSHD... not sure if the NEC utilities would even
fit on a boot floppy of that size anyway.
IIRC, there were differences in track spacing--or
something to that
effect-- rendering writes to 360K media in 1.2M drives (or was it
vice versa?) problematic.
"1.2M" drives use track spacing at 96 tracks per inch. "360K"
double-sided drives use a 48 track/inch spacing. So, to read and write
DD media, IBM adopted the convention of writing or reading every other
track when in "360K" mode. This works fine if you stay on a "1.2M"
drive, but creates havoc with "360K" drives picking up garbage on the
wider track. This can be avoided if the disk is thoroughly degaussed
(such as by using a videotape bulk eraser) before formatting in a 96 tpi
drive.
But to your problem. The normal configuration for a "1.2M" floppy drive
is to use pin 2 (REDWC) as a density indicator, a high level = low
density; a low level is high density. If the input is NC, or high,
you'll crash and burn on DSHD media.
--Chuck
2 Feb
2 Feb
6:42 p.m.
On 2/02/2014 9:03 a.m., John P. Willis wrote:
Swapping the 5.25" and 3.5" drives in the
NEC is out, since I would
again need to get to the BIOS
settings in order to make it all work.
Switch the drives anyway. It should still boot off the 1.44 even if the
BIOS setting is wrong.
7:22 p.m.
On 2014-02-02 19:42, Jonathan Chote wrote:
On 2/02/2014 9:03 a.m., John P. Willis wrote:
Will try it and post updates to the list.
Swapping the 5.25" and 3.5" drives in
the NEC is out, since I would
again need to get to the BIOS
settings in order to make it all work.
Switch the drives anyway. It should still boot off the 1.44 even if
the BIOS setting is wrong.
3979
days inactive
3981
days old
7 comments
4 participants
participants (4)
-
cclist＠sydex.com -
cisin＠xenosoft.com -
jonathan.chote＠gmail.com -
jpw＠coherent-logic.com