30 Dec
2010
30 Dec
'10
7:50 p.m.
Although the HP Portable+ Technical Reference doesn't contain anything on
the physical disk formats, there's a table in the usner manual for the
FORMAT comamnd (I've changed the headings a bit, but the data is the
same) :
Specifier #sides Secotr size Capacity Files in root dir
/w 1 256 264192 128
/x 2 256 618496 304
/y 2 512 700416 176
/z 2 1024 780288 96
none 2 512 700416 176
The default seems to be the same as other HP MS-DOS double-sided disks.
I wonder if Chuck (I think) got a disk formatted wit hthe /z option from
a Portable+ and sassumed it was the defualt?
-tony
30 Dec
30 Dec
8:06 p.m.
On 30 Dec 2010 at 19:50, Tony Duell wrote:
I wonder if Chuck (I think) got a disk formatted wit
hthe /z option
from a Portable+ and sassumed it was the defualt?
Perhaps--I do rely on samples sent by customers. If the customer
gets the product and it works just fine for them, I consider the case
closed.
The fact that someone identified the sample with any accuracy at all
was remarkable. I've had samples given as being from a Hazeltine
computer (the customer not realizing that the terminal was made by
Hazeltine, not the computer itself) or, lately and more common--
"here's a box of floppies; I don't remember what they came from."
That can be a real adventure, seeing word-processor disks mixed in
with old 400K Mac disks mixed in with various flavors of MS-DOS and
CP/M disks.
--Chuck
9:07 p.m.
On 30 Dec 2010 at 19:50, Tony Duell wrote:
Sure. And the Portable+ most certainly can format a disk with 1024 byte
sectors, etc, as standard
However, it does appear that by default the HP MS-DOS machines of the
time did have a common disk format which makes a lot more sense.
-tony
I wonder if Chuck (I think) got a disk formatted
wit hthe /z option
from a Portable+ and sassumed it was the defualt?
Perhaps--I do rely on samples sent by customers. If the customer
gets the product and it works just fine for them, I consider the case
closed. 
10:44 p.m.
On Thu, 30 Dec 2010, Chuck Guzis wrote:
The fact that someone identified the sample with any
accuracy at all
was remarkable. I've had samples given as being from a Hazeltine
computer (the customer not realizing that the terminal was made by
Hazeltine, not the computer itself) or, lately and more common--
"here's a box of floppies; I don't remember what they came from."
That can be a real adventure, seeing word-processor disks mixed in
with old 400K Mac disks mixed in with various flavors of MS-DOS and
CP/M disks.
. . . and also, disks that were used on one system and then reused on a
different one. The first side has a different format than the second
side, nine sectors per track with 8 used for a different file system than
the ninth, or a bogus MS-DOS directory left behind on track 0 and a CP/M
directory on track 2.
. . . or calling 3.5" diskettes "hard-sector"
. . . or calling 40 cylinder DSDD "Quad", and calling 80 cylinder DSDD
"SD"! (Superbrain)
--
Grumpy Ol' Fred cisin at xenosoft.com
10:49 p.m.
On 30 Dec 2010 at 14:44, Fred Cisin wrote:
. . . and also, disks that were used on one system and
then reused on
a different one. The first side has a different format than the
second side, nine sectors per track with 8 used for a different file
system than the ninth, or a bogus MS-DOS directory left behind on
track 0 and a CP/M directory on track 2.
. . . or calling 3.5" diskettes "hard-sector"
. . . or calling 40 cylinder DSDD "Quad", and calling 80 cylinder
DSDD "SD"! (Superbrain)
Or including ZIP disks in the mix (it's happened to me) as
"floppies". Fortunately, I haven't yet gotten any SuperDisks in the
mix.
--Chuck
31 Dec
31 Dec
7:33 p.m.
. . . and also, disks that were used on one system and
then reused on a
different one. The first side has a different format than the second
side, nine sectors per track with 8 used for a different file system than
the ninth, or a bogus MS-DOS directory left behind on track 0 and a CP/M
directory on track 2.
Disks that have been used on a double-head drive (or have been
factory-formatted for such a drive) which are then reformetted and used
on a single-head drive can have some odd remnants on side 1.
The other odd one is to have a machine that formats, say, 8 sectors per
track, nd use a pre-formatted disk with 9 sectors per track (otheriwse
identical format) in it. Most of the time it works fine (the machine will
only loo kf or the first 8 sector headers). But if you come to analyse
such a disk, you see this odd extra sector that is there for no good reason.
. . . or calling 3.5" diskettes
"hard-sector"
Sinc ethe index signal in a 35." drive comes from a sensor in the motor
(not from any kind of hole in the disk), I believe hard-sectored 3.5"
disks are impossible., at least using the normal definiton of 'hard
sectored'. Hard sectored 3" disks would be possible (there is an index
hole in rthe disk and a normal LED + phototransistor sensor), but AFAIK
no such disks were ever made. I don;t know about 3.25", etc.
. . . or calling 40 cylinder DSDD "Quad",
and calling 80 cylinder DSDD
"SD"! (Superbrain)
ARGH!
What about disks with 2 different filesystems on the same side of the
same disk?
-tony
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