miker@porkface2.WV.TEK.COM (06/01/90)
I acquired a Blue Chip 128 disk drive with no manual. The power-up message says CBM dos V3.0 1571. On a C128 it formats double sided and shows 13XX blocks free. When I stick the same drive and previously formatted 128 diskette on the C64, it reads the usual 664 blocks free. It seems to accept files normally. This is all confusing. If it's formatted 1328blocks, the Directory should be bigger and I should show fewer than 664 blocks free?? If the recording method is different, why does it even read in the wrong mode? Is there a way to get the full capacity on the C64? The eratta sheet with the 1571 manual gives an incantation something like open 1,8,15,"UO>M1" to lock the drive into 1571 mode. On the blue chip using the C64 it just locks up the drive. Is the Blue Chip 128 different? Ideas? I don't own a real 1571 or C128 to experiment on. Thanks, miker
jgreco@archimedes.math.uwm.edu (Joe Greco) (06/01/90)
In comp.sys.cbm article <7298@orca.wv.tek.com>, miker@porkface2.WV.TEK.COM () wrote: :I acquired a Blue Chip 128 disk drive with no manual. The power-up :message says CBM dos V3.0 1571. On a C128 it formats double sided and :shows 13XX blocks free. When I stick the same drive and previously :formatted 128 diskette on :the C64, it reads the usual 664 blocks free. It seems to accept files :normally. This is all confusing. If it's formatted 1328blocks, the :Directory should be bigger and I should show fewer than 664 blocks :free?? If the recording method is different, why does it even read in :the wrong mode? because Commodore didn't really do anything to the 1541 mode, to retain compatibility. The 1541 mode is not capable of recognizing more than 664 blocks; and it simply ignores the info on the disk that says that the disk is doublesided. There really ARE 664 free blocks. The fact that there are more on the other side is just something DOS 2.6 can't recognize. And the modes are basically identical, so the concept of "wrong mode" is very hazy. :Is there a way to get the full capacity on the C64? Of course. :-) :The eratta sheet with the 1571 manual gives an incantation something :like open 1,8,15,"UO>M1" to lock the drive into 1571 mode. On the blue :chip using the C64 it just locks up the drive. If really desperate, you can always power up the drive in 128 mode, unplug it, and plug it into the 64 (you have to give it at least one command in 128 mode). However, the correct user mode command will work just as nicely.. OPEN 15,8,15,"U0>M1" <= user command-there is no such thing as "UO" Your incantation might lock up a 1571 too. ;-) ... Joe