5 Nov
2020
5 Nov
'20
8:28 a.m.
I have a bankers box worth of dec ultrix 32 reference manuals in grey dec
binders. Im looking to sell the box of books for a few $ plus the cost of
shipping.
Hoping to find these books a good home.
--Devin D.
5 Nov
5 Nov
9:01 a.m.
On 2020-11-05 11:28 a.m., devin davison via cctalk wrote:
I have a bankers box worth of dec ultrix 32 reference
manuals in grey dec
binders. Im looking to sell the box of books for a few $ plus the cost of
shipping.
Hoping to find these books a good home.
--Devin D.
Please indicate location.
--Toby
11:04 a.m.
New subject: Floppy disk: one drive per face
We are trying to read some floppy disk used on a 1981 Italian Z80 machine
with CP / M.
The problem is that the firmware selects face A of the floppy as DRIVE A and
face B of the same floppy as Drive B.
We saved an image with IMD and we know that the geometry of face A is IBM
3740 26x128x77 tracks.
By inserting this data into the 22DISK definition file we can successfully
extract the CP / M files from A side.
How should we configure 22disk to be able to do the same thing on the B side
of the same floppy disk?
Inserting Side 2 in the definition table is not enough ....
Thanks Enrico - Pisa- Italy
11:31 a.m.
New subject: Floppy disk: one drive per face
On 11/5/2020 12:04 PM, Enrico email.it via cctalk wrote:
We are trying to read some floppy disk used on a 1981 Italian Z80 machine
with CP / M.
The problem is that the firmware selects face A of the floppy as DRIVE A and
face B of the same floppy as Drive B.
We saved an image with IMD and we know that the geometry of face A is IBM
3740 26x128x77 tracks.
By inserting this data into the 22DISK definition file we can successfully
extract the CP / M files from A side.
How should we configure 22disk to be able to do the same thing on the B side
of the same floppy disk?
Inserting Side 2 in the definition table is not enough ....
Thanks Enrico - Pisa- Italy
This local guy might know.
http://www.ummr.altervista.org/
A good view of computer history, from the land of pasta.
Ben.
12:10 p.m.
New subject: Floppy disk: one drive per face
On 11/5/20 11:31 AM, ben via cctalk wrote:
Don't know who that guy is, but I'm very well acquainted with the bozo
who wrote 22Disk.
On first blush, I'd declare the organization as ORDER EAGLE and use an
offset of 40 tracks+whatever is reserved on the other side.
See the SCH2 definition for example.
But that's just the shot-in-the dark opinion of this bozo.
--Chuck
Inserting Side
2 in the definition table is not enough ....
Thanks Enrico - Pisa- Italy
This local guy might know.
http://www.ummr.altervista.org/
A good view of computer history, from the land of pasta.
Ben. 
12:54 p.m.
New subject: Floppy disk: one drive per face
On 11/5/20 2:31 PM, ben via cctalk wrote:
On 11/5/2020 12:04 PM, Enrico email.it via cctalk
wrote:
I am not familiar with 22Disk. Can you image each side as a separate
image? That should make it possible to read both of them.
bill
We are trying to read some floppy disk used on a 1981 Italian Z80 machine
with CP / M.
The problem is that the firmware selects face A of the floppy as DRIVE
A and
face B of the same floppy as Drive B.
We saved an image with IMD and we know that the geometry of face A is IBM
3740 26x128x77 tracks.
By inserting this data into the 22DISK definition file we can
successfully
extract the CP / M files from A side.
How should we configure 22disk to be able to do the same thing on the
B side
of the same floppy disk?
Inserting Side 2 in the definition table is not enough ....
Thanks Enrico - Pisa- Italy
This local guy might know.
http://www.ummr.altervista.org/
A good view of computer history, from the land of pasta.
Ben.
1 Dec
1 Dec
7:05 a.m.
New subject: Intermec 8625
Hi All,
It might sound a bit strange, but I am looking for the manual for the
Intermec 8625 barcode printer. I need it for a museum project in the
danish Home Guard, but it seems to be just as rare a a hens teeth. I
would be very grateful if I could borrow the user manual for copying the
relevant parts.
Thanks in advance
Nico, OZ 1 BMC
5 Nov
5 Nov
1:50 p.m.
New subject: Floppy disk: one drive per face
On Thu, 5 Nov 2020, Enrico email.it via cctalk wrote:
We are trying to read some floppy disk used on a 1981
Italian Z80 machine
with CP / M.
The problem is that the firmware selects face A of the floppy as DRIVE A and
face B of the same floppy as Drive B.
We saved an image with IMD and we know that the geometry of face A is IBM
3740 26x128x77 tracks.
By inserting this data into the 22DISK definition file we can successfully
extract the CP / M files from A side.
How should we configure 22disk to be able to do the same thing on the B side
of the same floppy disk?
Inserting Side 2 in the definition table is not enough ....
An irrelevant data point, . . .
when double sided floppy drives came out for the PC/5150, there were some
patches informally distributed (ISTR mimeograpahed), for doing that with
PC-DOS 1.00! But, very soon thereafter, PC-DOS 1.10/MS-DOS 1.25 came out
that supported a full double sided format.
Is this an 8" disk? SSSD? (128 x 26 x 77)
(As you are presumably already aware, many PC FDCs have problems with FM
and/or 128 bytes per sector)
A really stupid HARDWARE way to do it would be to swap the wires for the
heads on the drive! Many drives have convenient plugs that would make
that easy.
Another stupid hardware way to do it would be to jumper side select, to
falsely select second side.
Chuck has provided a straight-forward solution. There were several
different ways that disk formats were expanded to double sided.
Some went up side A, and then DOWN side B
Some made use of the faster head switching than track stepping, and did a
track on one side, then a track on the other side. (which is the "modern"
standard, for MS-DOS, etc.)
SOME went up side A, and then went back to track 0 and then up side B.
With one of those formats, you could simply tell it that the "reserved
tracks" occupied the entire first side. (77 reserved tracks from your
description)
XenoCopy does not have such a format supported. I am not going to be
adding it at this time.
Uniform does not support it.
22Disk apparently has easily modified parameter tables, so should work
just fine. Thank Chuck!
--
Grumpy Ol' Fred cisin at xenosoft.com
XenoSoft http://www.xenosoft.com
2:42 p.m.
New subject: R: Floppy disk: one drive per face
About 5,25" diskettes it seems that its geometry could be based on 128byte
for sector so using FM recording way and 40 tracks for side it could have 18
sectors for track. If I try to format in this way a disk with 22disk program
I instead get 16 sectors for track. Having doubt on this we gone back to
look better on 8" diskettes to look deep about the way on which the b side
could be read. We can image that on 1980 they written before a way to record
just on one side of the diskettes and then they added double face diskettes
handling them as two separate drives (leaving the same sel 0 pin but
changing the side select pin to 1), so: why would have they rewrite all
instead of to replicate the same what already way made well on the first
side diskettes?
Enrico
-----Messaggio originale-----
Da: cctalk [mailto:cctalk-bounces at classiccmp.org] Per conto di Fred Cisin
via cctalk
Inviato: gioved? 5 novembre 2020 22:50
A: General Discussion: On-Topic and Off-Topic Posts
Oggetto: Re: Floppy disk: one drive per face
On Thu, 5 Nov 2020, Enrico email.it via cctalk wrote:
We are trying to read some floppy disk used on a 1981
Italian Z80 machine
with CP / M.
The problem is that the firmware selects face A of the floppy as DRIVE A
and
face B of the same floppy as Drive B.
We saved an image with IMD and we know that the geometry of face A is IBM
3740 26x128x77 tracks.
By inserting this data into the 22DISK definition file we can successfully
extract the CP / M files from A side.
How should we configure 22disk to be able to do the same thing on the B
side
of the same floppy disk?
Inserting Side 2 in the definition table is not enough ....
An irrelevant data point, . . .
when double sided floppy drives came out for the PC/5150, there were some
patches informally distributed (ISTR mimeograpahed), for doing that with
PC-DOS 1.00! But, very soon thereafter, PC-DOS 1.10/MS-DOS 1.25 came out
that supported a full double sided format.
Is this an 8" disk? SSSD? (128 x 26 x 77)
(As you are presumably already aware, many PC FDCs have problems with FM
and/or 128 bytes per sector)
A really stupid HARDWARE way to do it would be to swap the wires for the
heads on the drive! Many drives have convenient plugs that would make
that easy.
Another stupid hardware way to do it would be to jumper side select, to
falsely select second side.
Chuck has provided a straight-forward solution. There were several
different ways that disk formats were expanded to double sided.
Some went up side A, and then DOWN side B
Some made use of the faster head switching than track stepping, and did a
track on one side, then a track on the other side. (which is the "modern"
standard, for MS-DOS, etc.)
SOME went up side A, and then went back to track 0 and then up side B.
With one of those formats, you could simply tell it that the "reserved
tracks" occupied the entire first side. (77 reserved tracks from your
description)
XenoCopy does not have such a format supported. I am not going to be
adding it at this time.
Uniform does not support it.
22Disk apparently has easily modified parameter tables, so should work
just fine. Thank Chuck!
--
Grumpy Ol' Fred cisin at xenosoft.com
XenoSoft http://www.xenosoft.com
6 Nov
6 Nov
12:13 a.m.
New subject: R: Floppy disk: one drive per face
To elaborate on what I said earlier, consider the following set of
definitions for the CPC-6128 as marketed by Schneider:
BEGIN SCH1 Schneider CPC 6128 Side 1 - DSDD 5.25"
DENSITY MFM, LOW CYLINDERS 40 SIDES 1 SECTORS 9,512
SIDE1 0 193,194,195,196,197,198,199,200,201
BSH 3 BLM 7 EXM 0 DSM 180 DRM 63 AL0 0C0H AL1 0 OFS 0
END
BEGIN SCH2 Schneider CPC 6128 Side 2 - DSDD 5.25"
DENSITY MFM, LOW CYLINDERS 40 SIDES 2 SECTORS 9,512
SIDE1 0 193,194,195,196,197,198,199,200,201
SIDE2 0 193,194,195,196,197,198,199,200,201
BSH 3 BLM 7 EXM 0 DSM 180 DRM 63 AL0 0C0H AL1 0 OFS 40
ORDER EAGLE SKIP
END
Why the "SKIP" in the second definition? Well, if you wanted to format
the second side, you don't want CFMT to write all over the first side.
"SKIP" avoids this. Strictly speaking, SIDE1 in definition has no
significance, but 22Disk syntax requires it. You need the eggs with
your ham and eggs, even if you don't like them.
You have to figure that in a product that dates from 1987 that we've
pretty much seen it all.
--Chuck
12:19 a.m.
New subject: Floppy disk: one drive per face
On Thu, 5 Nov 2020, "Enrico email.it" wrote:
How should we configure 22disk to be able to do the
same thing on the B side
of the same floppy disk?
Inserting Side 2 in the definition table is not enough ....
Actually, it is almost that ;-)
I have a similar system, the fl100 floppy drive system, part of the
Grundig ptc100 (i.e. Mupid 2)
A: is side 0, and B: is side 1. Here's my 22disk definition for this.
Please note, the trick is to define a two-sided format for the second side
and first describe side 2 ! The definition of side 1 will be ignored
because the CP/M directory won't specify any block beyond the first side.
And of course, the track order is by cylinder, not by side.
BEGIN MUP1 Mupid Seite 1 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 1
SECTORS 10,256
SIDE1 0 0,2,4,6,8,1,3,5,7,9
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
BEGIN MUP2 Mupid Seite 2 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,256
SIDE2 0 0,2,4,6,8,1,3,5,7,9
SIDE1 0 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
Christian
8:35 a.m.
New subject: R: Floppy disk: one drive per face
So this for to read 1st face A:
BEGIN MUP1 Mupid Seite 1 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 1
SECTORS 10,256
SIDE1 0 0,2,4,6,8,1,3,5,7,9
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
And this for to read the other side B:
BEGIN MUP2 Mupid Seite 2 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,256
SIDE2 0 0,2,4,6,8,1,3,5,7,9
SIDE1 0 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
Right?
Enrico
-----Messaggio originale-----
Da: cctalk [mailto:cctalk-bounces at classiccmp.org] Per conto di Christian
Corti via cctalk
Inviato: venerd? 6 novembre 2020 09:20
A: General Discussion: On-Topic and Off-Topic Posts
Oggetto: Re: Floppy disk: one drive per face
On Thu, 5 Nov 2020, "Enrico email.it" wrote:
How should we configure 22disk to be able to do the
same thing on the B
side
of the same floppy disk?
Inserting Side 2 in the definition table is not enough ....
Actually, it is almost that ;-)
I have a similar system, the fl100 floppy drive system, part of the
Grundig ptc100 (i.e. Mupid 2)
A: is side 0, and B: is side 1. Here's my 22disk definition for this.
Please note, the trick is to define a two-sided format for the second side
and first describe side 2 ! The definition of side 1 will be ignored
because the CP/M directory won't specify any block beyond the first side.
And of course, the track order is by cylinder, not by side.
BEGIN MUP1 Mupid Seite 1 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 1
SECTORS 10,256
SIDE1 0 0,2,4,6,8,1,3,5,7,9
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
BEGIN MUP2 Mupid Seite 2 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,256
SIDE2 0 0,2,4,6,8,1,3,5,7,9
SIDE1 0 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
Christian
11:41 a.m.
New subject: R: Floppy disk: one drive per face
On Fri, 6 Nov 2020, Enrico email.it via cctalk wrote:
We are trying to read some floppy disk used on a 1981
Italian Z80
machine with CP / M.
We saved an image with IMD and we know that the geometry of face A is
IBM 3740 26x128x77 tracks.
By inserting this data into the 22DISK definition file we can
successfully extract the CP / M files from A side.
So this for to read 1st face A:
BEGIN MUP1 Mupid Seite 1 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 1
SECTORS 10,256
SIDE1 0 0,2,4,6,8,1,3,5,7,9
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
And this for to read the other side B:
BEGIN MUP2 Mupid Seite 2 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,256
SIDE2 0 0,2,4,6,8,1,3,5,7,9
SIDE1 0 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
Right?
WRITE PROTECT ALL OF THOSE DISKS, BEFORE YOU START!
Can you tell us the NAME of the machine?
(Unless the NAME is "1981 Italian Z80")
WHAT SIZE disk is it?
Is it 26 128 byte sectors, or
is it 10 256 byte sectors?
35, 40, 70, 77, or 80 cylinders/tracks?
What kind of drive?
3"? 3.25"? 3.5"?
((8" 26 * 128 * 77) is not the same as (5.25" 10 * 256 * 80))
Yes, a 5.25" SSSD disk CAN hold 18 128 byte sector per track, but you
might have to squeeze the [inter-sector] gaps a little, so 16 may be a
more conservative choice.
In the sector headers, . . .
On the second side, is the "HEAD NUMBER" field, in the C/H/R/N sector
headers, 0? or 1?
If 0, then you really should try unplugging the heads of the drive and
swapping them. That will put "side A/0" on the second/B side of the
disk.
If the "HEAD NUMBER" field, in the C/H/R/N sector headers, is 1
Then you are best off doing as Chuck suggested, and LYING to the transfer
program to tell it that it is a format that goes UP the first side, then
retracts to track 0 and then goes UP the second side, (there were
numerous formats that did that) but that you want the transfer program to
IGNORE the first half of each disk ("side A"). Ignoring the first half in
that case can be done on a CP/M disk by saying that the number of
"RESERVED TRACKS" (system tracks to be ignored for data transfer) includes
the entire first side, and the first few of the second side.
If you can image the disk with a DOCUMENTED image structure, then
consider writing some trivial code to split the image, to give you
separate images of the two sides, and then try to read the files from
each of those, as if they were two single sided drives.
Or, write a disk copy program to read the second side, and copy it to the
first side of a scratch disk.
BTW, the "each side is a separate drive" patches for PC-DOS 1.00 were 8
512 byte sectors on each side, with 40 tracks, so those would not help.
Yes, we're all bozos on this bus. ("Firesign Theater" fourth album)
But, when it comes to disk formats,
none of the rest of us bozos can compare to Chuck.
This is the greatest "don't try to teach your
grandmother how to steal
sheep" moment I've seen all year. \o/
BTW, in cultures that frown on
stealing sheep, that is sometimes
expressed as "teaching grandma to suck eggs".
--
Grumpy Ol' Fred Cisin cisin at xenosoft.com
XenoSoft http://www.xenosoft.com
12:27 p.m.
New subject: R: Floppy disk: one drive per face
On 11/6/20 11:41 AM, Fred Cisin via cctalk wrote:
Yes, we're all bozos on this bus.? ("Firesign
Theater" fourth album)
But, when it comes to disk formats,
none of the rest of us bozos can compare to Chuck.
I can claim size 13 feet, so I'm pretty much on the way to being a real
Bozo. Perhaps my mistake with 22Disk was not putting a line in that
said "Me fecit Carolus Guzis Anno MCMLXXXVII" or some such.
BTW, in cultures that frown on stealing sheep, that is
sometimes
expressed as "teaching grandma to suck eggs".
That's the way I've always heard the expression, but I never asked
either of my grandmothers if they could suck eggs. Never occurred to me
to do so.
--Chuck
1:19 p.m.
New subject: R: R: Floppy disk: one drive per face
First of all I would like to thank you all for every suggestion that comes
from so much experience. I only know my Ferguson
bigboard 1 pretty well
The z80 based machine was called GENERAL PROCESSOR Model T year 1981.
You can see it here: https://www.vintagesbc.it/?page_id=877 and the cards it
was equipped with here: https://www.vintagesbc.it/?page_id=879 even if it is
old information because I, together with a competent hardware technician and
another enthusiast who has already written an emulator HERE:
https://nippur72.github.io/gpmodelt-emu/ (you have to press CR to start then
BD and enter ...)
and the emulator video here:
https://www.youtube.com/watch?v=cRmmUYkaDxs&feature=youtu.be we are
proceeding to derive electrical schematics, save firmware, software, and try
to reconstruct and document everything.
You have to think that they used a WD1791 which has an inverted data bus and
in the firmware they use CPL instruction to invert it again so on the disk
the CP / M (CCP + BDOS + bios) is written all INVERTed.
Based on the firmware on eprom configuration it could manage:
- 2 drives 8 "(128x26x77) or 5" (128x18 (maybe 16) x40) all in FM and seen
as A, b, c, d
- 1 8 "DSDD single B unit and 1 HD 10MB Winchester drive (divided into 2
halves A and C)
At the beginning the engineers made ibm 3740 in side A. Only after they
passed to make a drive double face so we think they didn't change things
also because it seems to be possible to boot from both side A and side B and
we expect the side B of drive A it would in IBM 3740 format.
We noticed that the sectors always start from ZERO and not from 1 so it is
interesting what you say: ?you really should try unplugging the heads of the
drive and swapping them. That will put "side A / 0" on the second / B side
of the disk.! "
Enrico
-----Messaggio originale-----
Da: cctalk [mailto:cctalk-bounces at classiccmp.org] Per conto di Fred Cisin
via cctalk
Inviato: venerd? 6 novembre 2020 20:41
A: General Discussion: On-Topic and Off-Topic Posts
Oggetto: Re: R: Floppy disk: one drive per face
On Fri, 6 Nov 2020, Enrico email.it via cctalk wrote:
We are trying to read some floppy disk used on a 1981
Italian Z80
machine with CP / M.
We saved an image with IMD and we know that the geometry of face A is
IBM 3740 26x128x77 tracks.
By inserting this data into the 22DISK definition file we can
successfully extract the CP / M files from A side.
So this for to read 1st face A:
BEGIN MUP1 Mupid Seite 1 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 1
SECTORS 10,256
SIDE1 0 0,2,4,6,8,1,3,5,7,9
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
And this for to read the other side B:
BEGIN MUP2 Mupid Seite 2 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,256
SIDE2 0 0,2,4,6,8,1,3,5,7,9
SIDE1 0 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
Right?
WRITE PROTECT ALL OF THOSE DISKS, BEFORE YOU START!
Can you tell us the NAME of the machine?
(Unless the NAME is "1981 Italian Z80")
WHAT SIZE disk is it?
Is it 26 128 byte sectors, or
is it 10 256 byte sectors?
35, 40, 70, 77, or 80 cylinders/tracks?
What kind of drive?
3"? 3.25"? 3.5"?
((8" 26 * 128 * 77) is not the same as (5.25" 10 * 256 * 80))
Yes, a 5.25" SSSD disk CAN hold 18 128 byte sector per track, but you
might have to squeeze the [inter-sector] gaps a little, so 16 may be a
more conservative choice.
In the sector headers, . . .
On the second side, is the "HEAD NUMBER" field, in the C/H/R/N sector
headers, 0? or 1?
If 0, then you really should try unplugging the heads of the drive and
swapping them. That will put "side A/0" on the second/B side of the
disk.
If the "HEAD NUMBER" field, in the C/H/R/N sector headers, is 1
Then you are best off doing as Chuck suggested, and LYING to the transfer
program to tell it that it is a format that goes UP the first side, then
retracts to track 0 and then goes UP the second side, (there were
numerous formats that did that) but that you want the transfer program to
IGNORE the first half of each disk ("side A"). Ignoring the first half in
that case can be done on a CP/M disk by saying that the number of
"RESERVED TRACKS" (system tracks to be ignored for data transfer) includes
the entire first side, and the first few of the second side.
If you can image the disk with a DOCUMENTED image structure, then
consider writing some trivial code to split the image, to give you
separate images of the two sides, and then try to read the files from
each of those, as if they were two single sided drives.
Or, write a disk copy program to read the second side, and copy it to the
first side of a scratch disk.
BTW, the "each side is a separate drive" patches for PC-DOS 1.00 were 8
512 byte sectors on each side, with 40 tracks, so those would not help.
Yes, we're all bozos on this bus. ("Firesign Theater" fourth album)
But, when it comes to disk formats,
none of the rest of us bozos can compare to Chuck.
This is the greatest "don't try to teach your
grandmother how to steal
sheep" moment I've seen all year. \o/
BTW, in cultures that frown on
stealing sheep, that is sometimes
expressed as "teaching grandma to suck eggs".
--
Grumpy Ol' Fred Cisin cisin at xenosoft.com
XenoSoft http://www.xenosoft.com
2:15 p.m.
New subject: R: R: Floppy disk: one drive per face
On Fri, 6 Nov 2020, Enrico email.it via cctalk wrote:
First of all I would like to thank you all for every
suggestion that comes
from so much experience. I only know my Ferguson bigboard 1 pretty well
The z80 based machine was called GENERAL PROCESSOR Model T year 1981.
You can see it here: https://www.vintagesbc.it/?page_id=877 and the cards it
was equipped with here: https://www.vintagesbc.it/?page_id=879 even if it is
old information because I, together with a competent hardware technician and
another enthusiast who has already written an emulator HERE:
https://nippur72.github.io/gpmodelt-emu/ (you have to press CR to start then
BD and enter ...)
and the emulator video here:
https://www.youtube.com/watch?v=cRmmUYkaDxs&feature=youtu.be we are
proceeding to derive electrical schematics, save firmware, software, and try
to reconstruct and document everything.
You have to think that they used a WD1791 which has an inverted data bus and
in the firmware they use CPL instruction to invert it again so on the disk
the CP / M (CCP + BDOS + bios) is written all INVERTed.
Based on the firmware on eprom configuration it could manage:
- 2 drives 8 "(128x26x77) or 5" (128x18 (maybe 16) x40) all in FM and seen
as A, b, c, d
- 1 8 "DSDD single B unit and 1 HD 10MB Winchester drive (divided into 2
halves A and C)
At the beginning the engineers made ibm 3740 in side A. Only after they
passed to make a drive double face so we think they didn't change things
also because it seems to be possible to boot from both side A and side B and
we expect the side B of drive A it would in IBM 3740 format.
We noticed that the sectors always start from ZERO and not from 1 so it is
interesting what you say: ?you really should try unplugging the heads of the
drive and swapping them. That will put "side A / 0" on the second / B side
of the disk.! "
You did an excellent job of answering the questions!
The NAME probably doesn't matter, but it's always good to include, in case
anybody here might possibly have previously dealt with it.
With a WD179x, it is a little surprising that they didn't use MFM ("double
density").
On the other hand, 8" SSSD is "THE STANDARD", so must be supported, and/or
if earlier models had used the WD1771 FDC, this could be a legacy format.
The extreme standardization of CP/M 8" SSSD is another reason to justify
the replication onto second side, instead of changing the format. I once
pleaded with Gary Kildall to officially declare a 5.25" secondary disk
format standard. His reply was, "THE STANDARD is 8 inch Single Sided
Sigle Density."; it was understandable that he would not tolerate creation
of a "secondary standard". Although, we ended up with about 2500
different microcomputer disk formats, due to the lack of standards for 8"
DSSD, 8" SSDD, 8" DSDD, 5.25" SSSD, 5.25" DSSD, 5.25" SSDD,
5.25" DSDD.
(MOST of which could have been prevented with an official proclamation
from DRI.)
Swapping the head cables might be a simple way around it, IFF the second
side is formatted exactly the same as the first. One obvious possible
difference is the head number field in the sector headers. If EXACTLY the
same, then both would have 0 in that field. BUT, it could have 1 on the
second side (which will make it easier to read with an NEC chip). And,
the WD179x controllers didn't really care much about that field, so it
could be ANYTHING, including wildly wrong numbers. In most cases, the WD
chip wouldn't even notice if that field had the wrong value, but the NEC
chip needs to know what value to expect and look for.
If the imaging that included the second side was done successfully with
IMD, then that implies a 1 in the head number field on the second side.
Not insurmountable, but it means that just swapping the heads will still
require some special software.
If the imaging that included the second side was done successfully with
IMD, then consider the possibility of either doing the file transfers from
those images, or writing some minor software to split those images into
two separate single sided images.
The inverted data isn't a serious problem, although it is inconvenient
when looking at the data to see whether it is successful. But, it is easy
to work around.
Another possible complication, if you are trying to do the transfer on a
PC is that the WD179x controllers could start the beginning of a track
sooner after the index pulse than the PC NEC765 controllers can handle.
That is usually not too hard to work around, but is something to watch
for, particularly if you get failures to read the first sector of each
track.
Not all NEC floppy controllers can do FM and/or 128 byte sectors. Dave
Dunfield has created some test routines for checking that.
--
Grumpy Ol' Fred cisin at xenosoft.com
8 Nov
8 Nov
11:41 p.m.
New subject: R: Floppy disk: one drive per face
On Fri, 6 Nov 2020, "Enrico email.it" wrote:
So this for to read 1st face A:
BEGIN MUP1 Mupid Seite 1 - SSSD 96 tpi 5.25"
[...]
And this for to read the other side B:
BEGIN MUP2 Mupid Seite 2 - SSSD 96 tpi 5.25"
[...]
Absolutely correct :-)
Christian
6 Nov
6 Nov
9:07 a.m.
New subject: Floppy disk: one drive per face
On 11/6/20 12:19 AM, Christian Corti via cctalk wrote:
BEGIN MUP1? Mupid Seite 1 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 1
SECTORS 10,256
SIDE1 0 0,2,4,6,8,1,3,5,7,9
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
BEGIN MUP2? Mupid Seite 2 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,256
SIDE2 0 0,2,4,6,8,1,3,5,7,9
SIDE1 0 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
I prefer my solution. If you opt to format the second side, you'll end
up clobbering the first side in the process. But then, what does this
bozo know?
--Chuck
9:21 a.m.
New subject: Floppy disk: one drive per face
On Fri, 6 Nov 2020, Chuck Guzis via cctalk wrote:
On 11/6/20 12:19 AM, Christian Corti via cctalk
wrote:
FYI Christian, in case you weren't aware the "bozo" above /wrote/ 22disk.
:D
This is the greatest "don't try to teach your grandmother how to steal
sheep" moment I've seen all year. \o/
g.
--
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.
http://www.diy-cockpits.org/coll - Go Collimated or Go Home.
Some people collect things for a hobby. Geeks collect hobbies.
ScarletDME - The red hot Data Management Environment
A Multi-Value database for the masses, not the classes.
http://scarlet.deltasoft.com - Get it _today_!
BEGIN MUP1? Mupid Seite 1 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 1
SECTORS 10,256
SIDE1 0 0,2,4,6,8,1,3,5,7,9
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
BEGIN MUP2? Mupid Seite 2 - SSSD 96 tpi 5.25"
DENSITY FM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,256
SIDE2 0 0,2,4,6,8,1,3,5,7,9
SIDE1 0 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
BSH 4 BLM 15 EXM 1 DSM 96 DRM 127 AL0 0C0H AL1 0 OFS 3
END
I prefer my solution. If you opt to format the second side, you'll end
up clobbering the first side in the process. But then, what does this
bozo know?
8 Nov
8 Nov
11:50 p.m.
New subject: Floppy disk: one drive per face
On Fri, 6 Nov 2020, geneb wrote:
I know that *g*
But I haven't read Chuck's solution before sending my post. And BTW my
22disk entries are quite old (I think 15 years or so) and the
documentation[1] does not mention the keyword "EAGLE". So how could I know
about it??
Christian
[1]
File 22DISK.DOC from the 22DISK V1.44 package
"[...]
22DISK
A CP/M-to-DOS Diskette Interchange Utility
Version 1.40, September, 1993
Copyright 1988-1993, Sydex, Inc.
[...]
"
The README
" 22DISK Version 1.44
Distribution Information
October, 1996
[...]
"
On Fri, 6 Nov 2020, Chuck Guzis via cctalk wrote:
[...]
I prefer my
solution. If you opt to format the second side, you'll end
up clobbering the first side in the process. But then, what does this
bozo know?
FYI Christian, in case you weren't aware the "bozo" above
/wrote/ 22disk. :D
9 Nov
9 Nov
8:42 a.m.
New subject: Floppy disk: one drive per face
On 11/8/20 11:50 PM, Christian Corti via cctalk wrote:
On Fri, 6 Nov 2020, geneb wrote:
I know that *g*
But I haven't read Chuck's solution before sending my post. And BTW my
22disk entries are quite old (I think 15 years or so) and the
documentation[1] does not mention the keyword "EAGLE". So how could I
know about it??
Did you register your copy 15 years ago? If so, you're entitled to free
updates. Just saying...
--Chuck
On Fri, 6 Nov 2020, Chuck Guzis via cctalk wrote:
[...]
I prefer
my solution.? If you opt to format the second side, you'll end
up clobbering the first side in the process.?? But then, what does this
bozo know?
FYI Christian, in case you weren't aware the "bozo" above
/wrote/
22disk. :D 
9:19 a.m.
New subject: Floppy disk: one drive per face
On Mon, 9 Nov 2020, Chuck Guzis via cctalk wrote:
On 11/8/20 11:50 PM, Christian Corti via cctalk
wrote:
Can it still be registered?
g.
--
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.
http://www.diy-cockpits.org/coll - Go Collimated or Go Home.
Some people collect things for a hobby. Geeks collect hobbies.
ScarletDME - The red hot Data Management Environment
A Multi-Value database for the masses, not the classes.
http://scarlet.deltasoft.com - Get it _today_!
On Fri, 6 Nov 2020, geneb wrote:
I know that *g*
But I haven't read Chuck's solution before sending my post. And BTW my
22disk entries are quite old (I think 15 years or so) and the
documentation[1] does not mention the keyword "EAGLE". So how could I
know about it??
Did you register your copy 15 years ago? If so, you're entitled to free
updates. Just saying... On Fri, 6 Nov 2020, Chuck Guzis via cctalk wrote:
[...]
I prefer
my solution.? If you opt to format the second side, you'll end
up clobbering the first side in the process.?? But then, what does this
bozo know?
FYI Christian, in case you weren't aware the "bozo" above
/wrote/
22disk. :D
12:41 p.m.
New subject: Floppy disk: one drive per face
On 11/9/2020 10:19 AM, geneb via cctalk wrote:
Can it still be registered?
Is the Author find able? Do he still have 8" floppies?
*** Will it NOT be lost in the mail with COVID 19 ***
Software today is the big if. The S-100 people are still
making new cards for old hardware.
http://www.s100computers.com/index.html Even a PDP11 for the S100 bus.
Ben.
2:10 p.m.
New subject: Floppy disk: one drive per face
On 11/9/20 12:41 PM, ben via cctalk wrote:
On 11/9/2020 10:19 AM, geneb via cctalk wrote:
What, is this a question akin to ????? ???????? ?????? ???????? I don't
think it would take a Delphic oracle to do that.
Hell, I still have 3.25" floppies.
--Chuck
Can it still be registered?
Is the Author find able? Do he still have 8" floppies?
2:21 p.m.
New subject: Floppy disk: one drive per face
On 11/9/2020 3:10 PM, Chuck Guzis via cctalk wrote:
On 11/9/20 12:41 PM, ben via cctalk wrote:
Oracles are even harder to find, than 8" floppies.
They know you are coming. :)
Ben.
On 11/9/2020 10:19 AM, geneb via cctalk wrote:
What, is this a question akin to ????? ???????? ?????? ???????? I don't
think it would take a Delphic oracle to do that.
Hell, I still have 3.25" floppies.
--Chuck
Can it still be registered?
Is the Author find able? Do he still have 8" floppies? 
10 Nov
10 Nov
9:20 a.m.
New subject: Floppy disk: one drive per face
On Mon, Nov 9, 2020 at 5:11 PM Chuck Guzis via cctalk
<cctalk at classiccmp.org> wrote:
What, is this a question akin to ????? ???????? ??????
???????? I don't
think it would take a Delphic oracle to do that.
Loving the classical references.
-ethan
9 Nov
9 Nov
3:03 p.m.
New subject: Floppy disk: one drive per face
> Can it still be registered?
On Mon, 9 Nov 2020, ben via cctalk wrote:
Is the Author find able? Do he still have 8"
floppies?
That can rapidly turn into "Does he WANT to be found?"
When he did a project, even a major one, it was with an implicit promise
of a REASONABLE period of support. Not a commitment to a lifetime
sentence of support without further compensation.
Make it worth his while. Provide him with an interesting sample disk.
Or an good tuba (Meinl-Weston or Alexander, not Cerveny).
Or a REALLY good meatball sandwich.
yes, he still has 8" floppies. Hard and soft-sectored.
(I had to ask my sister what were good tubas. She blows the last french
horn that Lawson personally made.)
--
Grumpy Ol' Fred
3:12 p.m.
New subject: Floppy disk: one drive per face
On Mon, 9 Nov 2020 at 21:41, ben via cctalk <cctalk at classiccmp.org> wrote:
Is the Author find able? Do he still have 8" floppies?
Dude. Really. Pay attention. The author has been posting in this thread.
--
Liam Proven ? Profile: https://about.me/liamproven
Email: lproven at cix.co.uk ? gMail/gTalk/gHangouts: lproven at gmail.com
Twitter/Facebook/LinkedIn/Flickr: lproven ? Skype: liamproven
UK: +44 7939-087884 ? ?R (+ WhatsApp/Telegram/Signal): +420 702 829 053
1239
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1265
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29 comments
13 participants
participants (13)
-
bfranchuk＠jetnet.ab.ca -
bill.gunshannon＠hotmail.com -
cc＠informatik.uni-stuttgart.de -
cclist＠sydex.com -
cctalk＠ibm51xx.net -
cisin＠xenosoft.com -
enrico.lazzerini＠email.it -
ethan.dicks＠gmail.com -
geneb＠deltasoft.com -
lproven＠gmail.com -
lyokoboy0＠gmail.com -
nico＠farumdata.dk -
toby＠telegraphics.com.au