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Need some help with 8 inch floppy drive...
- Thread starter Adventurer
- Start date
Adventurer
Experienced Member
Looks promising, only third line from bottom makes me unsureGive it a try
Did it. Tried. Mess on my desk becomes bigger and bigger.
The results:
I can write images to floppy and back, both in SD and DAD formats, and now with 500K rate even for SD images, no errors. However, Displaywriter fails to recognise any of them.
Now I can copy Textpack floppy to 18-th sector, then it appears there is no data. However, Displaywriter is not unable to read my image, and I believe the floppy is not fully copied...
I did an experiment - formatted a floppy on a Displaywriter, then wrote the DS/DD image of Textpack. It did not work, but Displaywriter was still able to read old label "DOC", so it is clear the data are missing.
Maybe interleave, Format, Read/Write gaps should be set manually. Would be good to hear something from someone, who had been able to restore Displaywriter images back to floppy disk...
Al Kossow
Documentation Wizard
try setting imagedisk to do an analysis on every track
a double-sided double-density Imagewriter disk should look like this
Cyl:0 Hd:0 500K FM 26 sectors size 128
Cyl 00 Hd 0 128 .CCC.C..dddddddddddddddddd 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:0 Hd:1 500K MFM 26 sectors size 256
Cyl 00 Hd 1 256 dddddddddddddddddddddddddd 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:1 Hd:0 500K MFM 26 sectors size 256
Cyl 01 Hd 0 256 ..........C............... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:1 Hd:1 500K MFM 26 sectors size 256
Cyl 01 Hd 1 256 .......................... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:2 Hd:0 500K MFM 26 sectors size 256
Cyl 02 Hd 0 256 .......................... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:2 Hd:1 500K MFM 26 sectors size 256
Cyl 02 Hd 1 256 .......................... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
a double-sided double-density Imagewriter disk should look like this
Cyl:0 Hd:0 500K FM 26 sectors size 128
Cyl 00 Hd 0 128 .CCC.C..dddddddddddddddddd 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:0 Hd:1 500K MFM 26 sectors size 256
Cyl 00 Hd 1 256 dddddddddddddddddddddddddd 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:1 Hd:0 500K MFM 26 sectors size 256
Cyl 01 Hd 0 256 ..........C............... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:1 Hd:1 500K MFM 26 sectors size 256
Cyl 01 Hd 1 256 .......................... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:2 Hd:0 500K MFM 26 sectors size 256
Cyl 02 Hd 0 256 .......................... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Cyl:2 Hd:1 500K MFM 26 sectors size 256
Cyl 02 Hd 1 256 .......................... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Chuck(G)
25k Member
I believe that Al might have something--the DW, IIRC, does use Deleted Data Marks on the early cylinders. IMD should be able to copy them.
Adventurer
Experienced Member
Already did that - without full analysis ImageDisk is unable to make an image to hard drive.
Now there are some good news after all - all day trying, but finally I managed to make a copy of the damaged Textpack 4 floppy on a Displaywriter itself. Now it boots in about 20 seconds instead of 6-7 minutes before. I now have 3 master floppies + the original damaged one, which can be read only in a Displaywriter.
Now I was able to make an image of the copied floppy with no read errors, however, some problems still remain.
First - it seems that floppy for the Textpack should be completely blank - if not, Displaywriter shows previous floppy label, and treats it as damaged document disk.
Second - even with blank floppy it is not a complete success - for the first time Displaywriter starts to read it, but few seconds later shows *02*.
I have a feeling that now I am very close to success, but something seems to be missing - could there be data on a floppy, which are not read by ImageDisk? Besides, judging from the file size (170K), it appears to be an image of SS/SD floppy, duplicated to DS/DD, rather than native DS/DD image.
Next task - will try the same with Teledisk...
Now there are some good news after all - all day trying, but finally I managed to make a copy of the damaged Textpack 4 floppy on a Displaywriter itself. Now it boots in about 20 seconds instead of 6-7 minutes before. I now have 3 master floppies + the original damaged one, which can be read only in a Displaywriter.
Now I was able to make an image of the copied floppy with no read errors, however, some problems still remain.
First - it seems that floppy for the Textpack should be completely blank - if not, Displaywriter shows previous floppy label, and treats it as damaged document disk.
Second - even with blank floppy it is not a complete success - for the first time Displaywriter starts to read it, but few seconds later shows *02*.
I have a feeling that now I am very close to success, but something seems to be missing - could there be data on a floppy, which are not read by ImageDisk? Besides, judging from the file size (170K), it appears to be an image of SS/SD floppy, duplicated to DS/DD, rather than native DS/DD image.
Next task - will try the same with Teledisk...
Chuck(G)
25k Member
IMD compresses its images, so size can be misleading. Use the "IMDU /B" utilitiy to extract an uncompressed image.
Adventurer
Experienced Member
No luck so far...
ImageDisk settings:
Interleave 1:1 (tried best guess)
Double stepping: off
Sides: As read (tried double as well)
Tracks: 77
Full analysis: on
Increased step rate from 8 to 15 - the same, just writes slower
Run align/diagnostics - high pitched noise on all tracks, data read/write fine.
One more thing puzzles me - I took Displaywriter system floppy (it's named NEGKKE), opened in ImageDisk, and choosed "Erase".
Expected: When put in a Displaywriter, it would display it as a blank floppy: "*******"
Real result: Displaywriter still was able to read the disk name "NEGKKE". The question is - from where?
ImageDisk settings:
Interleave 1:1 (tried best guess)
Double stepping: off
Sides: As read (tried double as well)
Tracks: 77
Full analysis: on
Increased step rate from 8 to 15 - the same, just writes slower
Run align/diagnostics - high pitched noise on all tracks, data read/write fine.
One more thing puzzles me - I took Displaywriter system floppy (it's named NEGKKE), opened in ImageDisk, and choosed "Erase".
Expected: When put in a Displaywriter, it would display it as a blank floppy: "*******"
Real result: Displaywriter still was able to read the disk name "NEGKKE". The question is - from where?
Chuck(G)
25k Member
If you create an image file, how many sectors does it say it copied? It should say 2002.
If you scan an "erased" floppy with IMD, do you get any reports of data?
If you scan an "erased" floppy with IMD, do you get any reports of data?
Adventurer
Experienced Member
According to ImageDisk, it has 2548 sectors:
Meanwhile I think I have found the problem - instead of real writing/formatting/erasing, it was only pretending to write. Textpack 4 floppy, erased and formatted, was still readable on IBM Displaywriter, although it had some trouble reading data from it.
I think it has to do something with unterminated input lines, strange, but with previous PC the drive was also the last one, but was able to read/write, although not in the formats I needed.
I tried to terminate them with 150 Ohm resistors, but floppy controller showed failure on boot - will try tomorrow with 1K resistors again. The drive write head is OK, since it was writing on another machine.
Still, the written images look OK in HEX editor - there is data, and the format is very similar to the ones uploaded in Bitsavers, so at least there is hope, that at least read function is working correctly.
Al Kossow
Documentation Wizard
have you been able to read any of the copies you've made on the imagewriter that can boot?
it is very strange that track 0 side 0 is double-density. In the images I've made t0 s0 is always single density.
it is very strange that track 0 side 0 is double-density. In the images I've made t0 s0 is always single density.
Adventurer
Experienced Member
I do not know if the images will work - I need to fix the drive first, as it is currently in a "read only" mode. I will report the results of testing as soon as the drive problems have been sorted out. If you are interested, I can mail you a copy of this particular Textpack 4 floppy (tested).
Adventurer
Experienced Member
This looks like a dead end for experimenting - even with input lines terminated (both - 150 Ohms and 1000 Ohms), both computers still manage to recognise two drives instead of one. I strongly suspect the write signal goes to the wrong lines because of it.
286 PC with ISA floppy controller:
Intel Celeron 2,6 Ghz with onboard floppy controller:
Input lines have been terminated:
Still, the PC with Celeron and best testfdc results (only unable to write SD in 128K - but completely fails when 8 inch drive is connected) seems suitable for my tasks, but ImageDisk fails to write/erase anything, but it looks like it is writing normally - heads move, FDADAP adapter shows correct track numbers etc. The only program which can format the disk is FDFORMAT, I can read/write in DOS after that, but it does not helps with Displaywriter data in any way. Whats even worse - it appears the reading is worse after terminating input lines, since it shows completely wrong data:
286 PC is in fact able to erase the disk with ImageDisk, but it fails in reading/writing, and BIOS recognises two 360K floppy drives.
Can anyone suggest what might be wrong? Tried different floppy cables, etc - still the same - two drives instead of one in the BIOS. I'm not sure if getting Adaptec SCSI card will solve the problem with data signals. I have no more ideas left...
286 PC with ISA floppy controller:
Intel Celeron 2,6 Ghz with onboard floppy controller:
Input lines have been terminated:
Still, the PC with Celeron and best testfdc results (only unable to write SD in 128K - but completely fails when 8 inch drive is connected) seems suitable for my tasks, but ImageDisk fails to write/erase anything, but it looks like it is writing normally - heads move, FDADAP adapter shows correct track numbers etc. The only program which can format the disk is FDFORMAT, I can read/write in DOS after that, but it does not helps with Displaywriter data in any way. Whats even worse - it appears the reading is worse after terminating input lines, since it shows completely wrong data:
286 PC is in fact able to erase the disk with ImageDisk, but it fails in reading/writing, and BIOS recognises two 360K floppy drives.
Can anyone suggest what might be wrong? Tried different floppy cables, etc - still the same - two drives instead of one in the BIOS. I'm not sure if getting Adaptec SCSI card will solve the problem with data signals. I have no more ideas left...
Chuck(G)
25k Member
I'm going to be lazy, but (a) what 8" drive are you using and (b) how is it jumpered (all jumpers, not just the ones that you think are important). I'm willing to go through the OEM specs and figure out how things should be.
8" drives on a PC are no big deal, really.
8" drives on a PC are no big deal, really.
Adventurer
Experienced Member
The drive is Shugart SA-851. Seek was not working until I added jumpers to DS and C. Drive select set to 1, but tried all other positions. By mistake I removed write protect feature - cut WP and soldered NP joints. What else - some pins are bent/broken due to shipping, but there were no jumpers in the package. I can solder the joints if needed. I used Shugart SA 850 OEM manual for troubleshooting, but it appears I'm out of ideas for now.
I hope the photo is clear enough to see? I can upload a larger version somewhere, if needed.
Chuck(G)
25k Member
Good enough--I'll get back later today on what I see.
Adventurer
Experienced Member
Attachments
Adventurer
Experienced Member
Made adjustments according to this picture:
PC-286
Now there is finally a single floppy drive in BIOS, stepper engages without DS and C connected. However, when i try to access the disk, stepper moves, but then a message appears "No interrupt from FDC controller". A jumper missing somewhere?
Strange, but drive is displayed as B: on Drive select1, and A: on drive select 2
PC-Celeron - shows error 601 on switching on - floppy controller failure, with the same configuration. Drive select change has no effect.
PC-286
Now there is finally a single floppy drive in BIOS, stepper engages without DS and C connected. However, when i try to access the disk, stepper moves, but then a message appears "No interrupt from FDC controller". A jumper missing somewhere?
Strange, but drive is displayed as B: on Drive select1, and A: on drive select 2
PC-Celeron - shows error 601 on switching on - floppy controller failure, with the same configuration. Drive select change has no effect.
Last edited:
Chuck(G)
25k Member
A PC doesn't use the "polled" feature of the FDC--and most controllers have it disabled. In general, a PC assumes the DS is active when a drive is being stepped.
No "no interrupt" is because the FDC doesn't see an index pulse, so something's still wrong.
Note that Shugart numbers their drive select from 1, not 0 (as do other makers), so you want DS2 in this case.
You don't want the drive select to function as a side select, so 1B..4B should be open.
In fact, but for DS2, the factory (in black) defaults should be the ones to use, if I'm reading them right.
No "no interrupt" is because the FDC doesn't see an index pulse, so something's still wrong.
Note that Shugart numbers their drive select from 1, not 0 (as do other makers), so you want DS2 in this case.
You don't want the drive select to function as a side select, so 1B..4B should be open.
In fact, but for DS2, the factory (in black) defaults should be the ones to use, if I'm reading them right.
Adventurer
Experienced Member
Well, the driveToday I connected the drive back to 286 PC - and suddenly it appears no longer working there - the BIOS recognised a single drive, but no seek and no access light anymore.
Even worse, after a while I have no access light /solenoid working without controller connected. I suspect 5V electronics have failed. Time to get a new(old drive)? I can remove all jumpers again and start debugging, but it appears something has gone completely wrong, since drive access light should light and solenoid should make a click when applying power without controller connected.
Even worse, after a while I have no access light /solenoid working without controller connected. I suspect 5V electronics have failed. Time to get a new(old drive)? I can remove all jumpers again and start debugging, but it appears something has gone completely wrong, since drive access light should light and solenoid should make a click when applying power without controller connected.
Chuck(G)
25k Member
If you apply power and ground the appropriate drive select, you should get the LED. Otherwise, nothing should happen, assuming that you have the correct pullups installed.