how to use only lower track (head 0)
#1
I have need to just use lower track as the drives are single sided only, is there a setting in the configuration file to cause it to use head 0 only?

Also reading the same disk from a known good drive at the same location (TK0, HD0) does not seem to produce consistent results.the buffer is different each time.

Thanks

W1ARQ  Howard
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#2
SSDD disk? You will get good results with the "C64/128" setting if you use a 48 TPI drive, which I can assure you that you're using one right now. Note that you must have half tracks disabled. Make sure to set the TPI setting as well.
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#3
No, there is no way to use just the lower head. Both heads are stored per the .scp file specification, whether the head is used or not.

The buffer will be different every time you read it (if you are looking at the flux data) because the flux changes lengths during reads due to the drive hardware clocking, drive speed, etc.
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#4
(01-21-2018, 09:58 PM)Jackson Wrote: SSDD disk? You will get good results with the "C64/128" setting if you use a 48 TPI drive, which I can assure you that you're using one right now. Note that you must have half tracks disabled. Make sure to set the TPI setting as well.

Yes, but I want MFM, not GCR - these are for Kaypro SSDD 48tpi CP/M.

(01-21-2018, 11:01 PM)admin Wrote: The buffer will be different every time you read it (if you are looking at the flux data) because the flux changes lengths during reads due to the drive hardware clocking, drive speed, etc.
I'm primarily interested in the data only, not the gap or post amble or other envelope information. Just the information as the HOST would see it. The HOST is usually not privy to info way down to the flux changes. Turning off the sync, headers, and invalid data did not produce repeatable results, of course I could be interpreting the concept all wrong here......

Thanks

W1ARQ Howard
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#5
"Yes, but I want MFM, not GCR - these are for Kaypro SSDD 48tpi CP/M."
The file is completely flux transitions. Disk types are minor details for emulators and file readers to use. You can archive these as C64 disks and get along with your day. HxC has autodetection where it can tell the encoding directly from the flux, so MFM streams will get decoded correctly regardless of disk type. However, HxC will not read the tracks correctly nor export them correctly to raw sector images because archived C64 SCP files tracks store twice the amount of tracks and have byte 0x0A (head count) set to zero to account for both heads, which are stored regardless of whether one head is used or not.

HxC's implementation parses this in a broken manner where 80 tracks, 40 of which are duplicates, are all stored on one head. You might be better off trying to dump these as IBM PC 360k disks, but I'm not sure how that fares when importing and exporting them that way in HxC either.

For my SSDD DOS 1.x/2.x disks, reading the raw sector export correctly from a C64 image requires making a new file which has every odd numbered 4096 byte chunk from the original. I have written a small tool to aid me in this situation: https://pastebin.com/zTp7yj3U

You can adjust the HUNK_SIZE define as well if the pattern of repeated bytes is bigger or smaller, i.e. 1024 bytes.
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#6
SuperCard Pro dumps flux data only. It does not decode to the MFM or sector level. There are many different tools that support the SCP hardware and .scp image file format.

HxC works just fine for any MFM formatted disk. You just need to make sure you are *not* using the C64 mode for dumping the data.
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#7
Well I apologize to you all as I obviously misunderstood what I was getting into here. I didn't realize that this little bugger does NOT distinguish between any format higher than flux changes.
While (I think !!) I understand this level of interfacing, is this useful for restoring and building old skool 8 bit operating system disks, or is this a better tool to service floppy drives with?

Thanks...W1ARQ Howard
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#8
(01-22-2018, 11:12 AM)admin Wrote: HxC works just fine for any MFM formatted disk. You just need to make sure you are *not* using the C64 mode for dumping the data.

This is somewhat what I've said earlier; HxC's SCP implementation was not tested on diskettes dumped with single sided double density settings. It is possible to extract, but the work is tedious.
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#9
Yes, HxC was tested with single sided disks. The upper head data is just ignored.
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