My experiments dumping pc 5 1/4 360K floppies

[anormal]

hi everyone,

after some initial testing here i started dumping many originals i have in my collection, i'll write here my results and notes, maybe it's useful for anyone, it was (and still it's very confusing at the beggining, many things (fluxes, stream files, mfm conversion, etc, etc...) and terms must be considered

i also feel there is not enough support for PC people as for c64/Amiga

NOTE: i only note commandline for first disk (timequest are 10 disks for example), as the rest is the same but changing disk number

NOTE: img file ok, to my understanding, it's when dtc generated a 368640 bytes img file, that i can load in dosbox with imgmount command (imgmount a filename.img -t floppy)

NOTE: disk protected means that the disk is write protected, so it has not been modified, NIB = new in box (i opened this box)

My drive stats:
Epson sd-600, 83 tracks calculated with -c2, ~359.6rpm checked with -c1

- Murder in the Atlantic (NIB and protected),
using gui, preservation and mfm, img file created ok

- Starcontrol NIB (some testing here with command line, as you can see -k2 position is critical, read the manual!)
DTC -fsc1 -i0 -fsc1.img -i4 = img file created bad with size 737280
DTC -fsc1 -i0 -fsc1.img -i4 -k2 = img file created bad with size 737280
DTC -fsc1 -i0 -k2 -fsc1.img -i4 = img file created ok with size 368640

- Empire 2.05 (disk protected but not NIB)
DTC -fempire -i0 -k2 -fempire.img -i4 = img file ok

- Dragon wars (disk protected but not NIB)
DTC -fdragon_wars_d1_ -i0 -k2 -fdwd1.img -i4 = img file ok

- Transylvania NIB (not been able to generate a valid img file)
DTC -ftransylvania -i0 -k2 -ftransyl.img -i4 = img file size 655360 (many errors)
use gui preservation only = ok
use gui mfm image = img size 655360 (bad)
DTC -k1 -ftransyl.img -i4 = img file size 1310720 (many errors)

- Oo-topos NIB
DTC -footopos -i0 -k2 -footopos.img -i4 = = img file size 655360 (bad)

- Battletech crescent hawk’s inception
DTC -fbtchi_d1_ -i0 -k2 -fbtchid1.img -i4 = img file ok

- Altered Destiny (disk protected but not NIB)
DTC -faltdest_d1_ -i0 -k2 -faltdest_d1.img -i4 = img file ok

- Timequest (disk protected but not NIB)
DTC -ftimequest_d1_ -i0 -k2 -ftimequest_d1.img -i4 = img file ok

- Simcity (disk protected but not NIB)
DTC -fsimcity_d1_ -i0 -k2 -fsimcity_d1.img -i4 = img file ok

- Third courier (NIB and protected)
DTC -fthirdc_d1_ -i0 -k2 -fthirdc_d1.img -i4 = img file ok
=============

i'll keep dumping disks and writing notes here, if admins consider i am doing something wrong just pm me

any ideas or tips about this, please please please share it!!

[mr.vince]

Just some quick thoughts... if you dump without a guide format, preservation (=stream, =raw data) will always be fine as flux itself is just a series of magnetic pulse changes... impossible to verify.

You can actually load your stream files right away in PCE: viewtopic.php?f=3&t=765

[anormal]

hi vince,

i tried to understand and use guide format, but i don't know exactly what it does, i can redump if necessary
for now, what i am doing is opening the img files with a img editor (as winimage) or mount it in dosbox and check the files

regardless of what other format i use (-i command) if i use -i0 and generate the raws, later all this could be processed and generate/check other formats?

that is, -i0 is all the important stuff? , if not? what commandline do you recommend?

also could you (or anyone here) explain me this? : afaik this drive unit is the old style, only 360kb can be used (it's from my first pc), so how HD can be readed? and if it's not HD, the rpms must be 300rpm instead of 360rpm ??

sorry if i can't explain better, english is not my mother language

thanks

[Feltzkrone]

HD cannot be read using that drive because it is 48 tpi while HD disks are written with 96 tpi (twice the number of tracks = twice the track density / half the track distance). You should really try to get a working HD drive for dumping disks. Please run DTC -c2 to figure out how many tracks your drive really can access. If maxtrack is something below 42 the drive is definitely not HD (and is 48 tpi), if maxtrack is something over 79 your drive is most probably HD (and 96 tpi) but you just didn't know yet.

Anything from -i3 to -i25 makes DTC try to decode the data delivered by the drive and retry reading tracks when an error occurs in the data, e.g. the checksum stored on disk does not match the data it is calculated from. You may or may not choose to store the decoded data in a sector image file by prepending a -fFilename.img option before the corresponding -i<type> option (in your case -i4). The same applies to many other options offered by DTC.

As the exact logical format of MFM formatted disks (and capabilities of the drives) has changed a bit over time and are also different across the many target platforms that use MFM, setting one or more of the following options before -i4 might come in handy, especially when a copy protection is present on disk which might fool DTC e.g. by using unusual sector numbers:

-g<side> (side mode)
-n<scnt> (sector count)
-k<step> (track distance)
-v<rpm> (target system RPM)

Please pay attention to the "IBM PC compatibles" section of the table of logical disk formats here: http://en.wikipedia.org/wiki/List_of_fl ... al_formats

These can be 1:1 translated to DTC options (assuming that you use a HD drive, if you keep using a DD drive the variants making use of -k1 do not work for you at all and instead of -k2 you'll have to use -k1), for example:

Sectors/track: 9, Tracks/side: 40, Sides: 2, RPM: 300
-z9 (9 sectors per track)
-k2 (40 tracks per side)
-v300 (target platform assumes 300 RPM, can be omitted as it's the default for -i4)

Sectors/track: 8, Tracks/side: 40, Sides: 1, RPM: 300
-z8 (8 sectors per track)
-k2 (40 tracks per side)
-g0 (single sided, side 0)
-v300 (target platform assumes 300 RPM, can be omitted as it's the default for -i4)

Sectors/track: 15, Tracks/side: 80, Sides: 2, RPM: 360
-z15 (15 sectors per track)
-k1 (80 tracks per side, could also be omitted because it's the default)
-v360 (target platform assumes 360 RPM)

At the end of the DTC command line (after all -i options) you might want to add -e<trk> where <trk> is the maximum track that your drive can access (as shown when using DTC -c2).

Please take a closer look at the included manual, it explains all of these options very well. And please to also take a look at DTC's output / logs. If you see *T, *S or *N warnings these are a hint that you're using a wrong disk format parameters (-z, -k, -g options). If you see many "unformatted" notes for even tracks the target RPM might be wrong, just use -v360 or leave out -v360 in that case.

As soon as you stumble upon a problematic disk that can not be handled correctly using this info please provide us with DTC's logs and/or upload stream files (-i0) of the first few tracks for both sides (in case that there's no sensitive data on the disk) so we can take a look and give you info what might be going wrong there.

[anormal]

thanks you very much for so much info,

this is my drive:
Epson sd-600, 83 tracks calculated with -c2, ~359.6rpm checked with -c1

I was confused about this, i remember this drive unit is very old, so no HD (if i remember ok), but as you see i got 83 tracks with -c2, and 360rpm
So, must i conclude this unit is able to read HD?

Could anyone with Epson SD-600 confirm something?

thanks for the rest of tips!

once i finnish dumping all my 5 1/4 pc material i'll upload to SPS

[Feltzkrone]

Google reveals that there are many sites stating that it is a 1.2M drive = HD. I would just try with a HD disk and look at the result.

[anormal]

hi,
thanks, resumed part of the article you linked here for further reference
most usual are marked with *

== 5 ¼ ================================
size = density, bytes/sector, sectors/track, tracks, sides, rpm
160KB = DD,512,8,40,1,300
320KB= DD,512,8,40,2,300
180KB= DD,512,9,40,1,300
360KB(*)= DD,512,9,40,2,300
1200KB(*) = HD,512,15,80,2,360

== 3 ½ ================================
size = density, bytes/sector, sectors/track, tracks, sides, rpm
320KB=DD,512,8,80,1,300
360KB=DD,512,9,80,1,300
640KB=DD,512,8,80,2,300
720KB(*)=DD,512,9,80,2,300
1440KB(*)=HD,512,18,80,2,300
1680KB=HD,512,21,80,2,300
1720KB=HD,512,21,82,2,300

[anormal]

hi!

is there a way i can test if my drive unit got de-calibrated? or something is going bad with it?

today i've been dumping, Worlds of Ultima 1 and 2 (Savage Empire and Martian Dreams) and Ultima 6 and i got tons of errors

if i upload some streams, looking at them anyone could tell me if my drive unit broke?

i am a bit depressed i was getting some fun dumping old floppies and then i got this...

[brightcaster]

I got the same results at my first attempts, till I found a lot of lttle spots (probable mold) on the disks surface! After cleaning everything went fine...

[Feltzkrone]

Feel free to upload some stream files. It should be rather easy to figure out the possible reasons for the errors. A few adjacent tracks per disk should be sufficient.

You can consider contributing your dumps of original disks later: http://www.softpres.org/contact - By contributing you not only help building a digital archive and preserving computer games but you also have a few people who can take a look at your dumps and point you at possible problems.