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Re: TA ScreenTyper 5.25 in. floppies

Posted: Wed Mar 15, 2017 7:36 pm
by brightcaster
Congrats! I also got some files of the disk. But they still look some kind of weird to my eyes and there are a lot of unreadable directory entries with the same name (00ch.wp) on the first disk.

I used this diskdefs with cpmtools:

# BEGIN screent TA/alphatronic screentyper - DSDD 48 tpi 5.25
diskdef screent
seclen 512
tracks 80
sectrk 10
blocksize 2048
maxdir 128
skew 0
boottrk 4
os 2.2
end

Do yours look similar?

David

Re: TA ScreenTyper 5.25 in. floppies

Posted: Wed Mar 15, 2017 10:47 pm
by ZrX
diskdef tast
seclen 512
tracks 80
sectrk 10
blocksize 2048
maxdir 64
skew 0
boottrk 2
os 2.2
end

I also had to manually hexedit the directory to remove spaces from the names or the files aren't found by cpmcp.

Re: TA ScreenTyper 5.25 in. floppies

Posted: Fri Mar 17, 2017 9:04 pm
by adamsabi
If anyone has success with extracting these files, please let send me a download link. Thanks again for your help here!

Re: TA ScreenTyper 5.25 in. floppies

Posted: Sat Mar 18, 2017 11:31 am
by brightcaster
Unfortunately, the files I get are not okay. There seems to be something wrong with the order in which the sectors are read. Looks for me as if an obscure skew or interleave has been used. It's a time consuming trial and error now...

I even thougt of writing your stream-images back to a disk and feed them to scopy or alien on my old DOS machine (just to see what the files have to look like and getting the correct sector order that way). But as you created the images with a 80 track drive I can,t simply write them to a 40 track using DTC!

It should also be possible on linux to format a disk with:

superformat dev/fd0 cyl=40 head=2 sect=10 ssize=512 dtr=2 tpi=48 dd

and write the mfm-decoded 400k images to it (simply using dd), but there is lack of hardware on my side (no more real floppy interface on my linux machine) ....


David

Re: TA ScreenTyper 5.25 in. floppies

Posted: Wed Mar 22, 2017 4:37 pm
by adamsabi
I was able to determine that MFM sector images can be opened on a contemporary Mac OS X and files can be copied over to the a file folder or storage device from there.