5.25 double density
#1
What's the proper setting for PC 5.25" double density disks? I have two of the Test Drive II scenery disks (California Challenge and European Challenge). I'm not positive they're DD, but I imaged them with the 1.44MB option (80 tracks, 2 heads) and in the analyzer every odd track looks like half-tracks do on C64 images, so that's why I'm guessing DD.
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#2
I use the 360K setting.
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#3
just look at a histogram of the data, fairly easy to see then what the right setting is, just look at a known DD and HD disk, the difference is obvious. (i am assuming the software can do this, as its one of the most basic analyzer options)
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#4
The problem isn't determining the format, it's what disk type to select from a menu that doesn't seem to have the correct option.

The 360K option reads in 80 tracks and 2 heads, but it should be 40 tracks with 2 heads. So what you get is essentially a 360K disk with "half-tracks". The other closest option is the C64/128 type, but that won't give you the data from the other head.
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#5
I'm gonna jump in the conversation with a newbie question, my apologies. I also have 5.25 PC floppies and I want to know how to identify a 5.25 floppy if it's dd or hd or the capacity 360k,1.2mb or whatever?
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#6
(01-15-2014, 05:24 PM)LordCrass Wrote: The problem isn't determining the format, it's what disk type to select from a menu that doesn't seem to have the correct option.The 360K option reads in 80 tracks and 2 heads, but it should be 40 tracks with 2 heads. So what you get is essentially a 360K disk with "half-tracks".
ah ok, not quite what you'd expect i guess.... not that it makes a big difference for the flux dump, what matters is that your flux-to-plain conversion handles it correctly Smile
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#7
(01-15-2014, 05:34 PM)longbow75 Wrote: I'm gonna jump in the conversation with a newbie question, my apologies. I also have 5.25 PC floppies and I want to know how to identify a 5.25 floppy if it's dd or hd or the capacity 360k,1.2mb or whatever?
There's 4 different 5.25" formats that I've heard of, although the most common are the 360K double-sided double-density (DSDD) and the 1.2MB double-sided high-density (HD).

The others are 8 and 9 sector single-sided single-density (160K/180K respectively).

If you look at a few tracks in the analyzer, you can tell pretty quickly between HD and DSDD. If you look at a few of the odd tracks and they look pretty clean, good chance it's an HD disk. If the data on there looks like it exploded, then it's probably a DSDD disk.

For the single-sided disks, looking at head 1 should show noise assuming the back of the disk wasn't used. I haven't personally seen the single sided PC disks in the analyzer, but you would probably be able to see the individual sectors in the pattern, and could then see if there are 8 or 9 of them. You can definitely see 9 sectors on the DSDD disks.

A quick google shows all kinds of other PC formats.. 320KB/400KB/720KB/1440KB, 8 sector double sided, 10 sector, etc..
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#8
You can change the TPI to adjust the stepping if needed. You can use C64/128 and 1/2 tracks to copy a 1.2MB disk too.

PC's use the index to start their tracks, so they copy easily.
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#9
(01-15-2014, 06:12 PM)LordCrass Wrote: There's 4 different 5.25" formats that I've heard of, although the most common are the 360K double-sided double-density (DSDD) and the 1.2MB double-sided high-density (HD).

The others are 8 and 9 sector single-sided single-density (160K/180K respectively).

[...]

A quick google shows all kinds of other PC formats.. 320KB/400KB/720KB/1440KB, 8 sector double sided, 10 sector, etc..

You have to differentiate between usual and rarer used formats.
1.2MB (80Trk/2S/15Sec/512BpS) and also 1.44MB (80 Trk/2S/18Sec/512BpS) for AT compatibles or better, named "HD", these are the most used formats.
360KB (40Trk/2S/9Sec/512BpS) is also used often for IBM PC XT and Compatibles, named "DD".
All other formats are officially used, but more rare:
720KB (80Trk/2S/9Sec/512BpS), also "DD" but was only used for some PS/2 and early laptops/notebooks.
160KB/180KB (40Trk/1S/8 or 9Sec/512BpS) - "DD" - only used for early PC (XT) and some bootable games.
320KB (40Trk/2S/8 Sec/512BpS) - "DD" - uncommon but also used in the beginning.
(800KB (80Trk/2S/10 Sec/512BpS) - "DD" - only used with additional formatter programs, is supported by higher DOS versions and DRIVER.SYS or DRIVPARM=... )

Note: "HD" was used with 360rpm rotation speed floppy drives, "DD" with 300rpm. Some HD drives can be configured as DD, see http://www.oldskool.org/disk2fdi/525HDMOD.htm ...

There were some DOS TSR programs which extends the BIOS, so all possible combinations can be used, also more than 80 Tracks, but this was not officially supported by Microsoft/IBM.
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#10
With SCP we don't care about format. The ONLY thing that matters is the head stepping... everything copies the same way.
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