Hello Ethan, * On Wed, Nov 15, 2017 at 03:46:32PM -0500 Ethan Dicks wrote: > On Wed, Nov 15, 2017 at 3:33 PM, <silverdr@wfmh.org.pl> wrote: [...] > The DOS 1.0 format (with the extra block in one zone) is the "2040" > format. DOS 2.0 and DOS 2.6 use the same on-disk format in terms of > sectors-per-track and are fully compatible. What might be different > is *I think* when you format a disk on DOS 2.0 (4040), the data bytes > are $00 and on DOS 2.6 (1541) the data bytes are $4b/$01... because of > an INX bug in DOS 2.6 (as documented in "Inside Commodore DOS", IIRC) The 4040 uses a different inter-sector gap than the 2031 and the 1540 on the one hand, and the 1541 and 1571 on the other hand. Note, however, that early ROMs of the 1541 (-01, -02) also used the inter-sector-gap of the 2031 and 1540. Thus, the later 1541 (starting with -03 ROM) should be fully read and write compatible with the earlier 1541, 1540, 2031 and 4040 disk. Thus is not true for 4040 disks and 2031, 1540 and (early) 1541 disks. > The primary problem is taking a DOS 1.0-formatted disk and wanting to > write to that on a newer drive. But it is nothing crucial that could not be handled by software. That is the part that I wanted to know. Regards, Spiro. -- Spiro R. Trikaliotis http://www.trikaliotis.net/ Message was sent through the cbm-hackers mailing listReceived on 2017-11-15 21:05:28
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