coop@image.rochester.edu (Optics Group co-op student) (02/17/89)
I have interfaced a 1.2Meg 5.25 floppy disk to my amiga 500. The problem I am having is that I can't format beyound 40 (0-39) tracks. When I mount the drive with 96 (0-95) tracks and try to format it, all the programs I use stop at track 40 and return an error. If I mount the drive as 40 track drive it works fine. Only the first 40 tracks on the disk are used. I have concluded that the problem must be in the trackdisk.device driver. All the manuals I could get my hands on indicate that the trackdisk.device driver is hardcoded for a maximum of 80 tracks for 3.5" drives and 40 tracks for 5.25" drives. What I need to know is ?? 1) Is it possible to alter the current driver's maximum track in some not too clugy (sp) way. 2) Can there be two trackdisk.device drivers in the system? Of course they would have different names but they would be manipulating the same disk control registers. 3) If it is possible to have more than one trackdisk driver I would appreciate some help writing the new driver. I have looked at several example drivers, but none of them would be easy to modify to be a floppy controller. 4) Any info on the AMIGA floppy hardware would be great. What I need to know is it possible to increase the number of sectors per track. On an IBM AT I think the 1.2 Meg floppy is formatted with 15 sectors per track. This would mean that 15K per track vs 10K with 11 sectors. Thats 1.5 MByte per disk. 5) Why doesn't the Fast File System work with floppies? The format works fine but files are always corrupt and there are no error messages. Any info would help. My name is Ray Stewart and I can be reached at HOME (716)334-2305 WORK (716)275-4425
dak@ut-emx.UUCP (Donald A Kassebaum) (02/17/89)
96 track per inch drives are 80 track devices. Many of these drives will work at 720k or 1.2m. They get 720k when run at 300 rpm and the standard 250k bit rate. They will get 1.2m when run at 360 rpm and a 500k bit rate. The amiga can only handle the 250k bit rate and would get 880k when run at 300 rpm. The amiga would not hold as much data if run at 360 rpm. Try playing around with the mount list to get 80 tracks. I have built a 5.25 floppy drive with autoconfig and diskchange. The amiga can't tell the difference. I have been working on an article, but haven't found an universal way to do diskchange. Any ideas? If anyone is interested, send me mail. Enough interested may get a usenet post. Dak
andy@cbmvax.UUCP (Andy Finkel) (02/21/89)
In article <876@ur-cc.UUCP> coop@image.rochester.edu (Optics Group co-op student) writes: > >I have interfaced a 1.2Meg 5.25 floppy disk to my amiga 500. >The problem I am having is that I can't format beyound 40 (0-39) tracks. > >I have concluded that the problem must be in the trackdisk.device >driver. All the manuals I could get my hands on indicate that the >trackdisk.device driver is hardcoded for a maximum of 80 tracks for 3.5" >drives and 40 tracks for 5.25" drives. if you just connected a standard 1.2 meg IBM PC style floppy to your Amiga disk connecter, I think you'll be running into some limits on speed that Paula can read raw bits from the disk. >5) Why doesn't the Fast File System work with floppies? The format >works fine but files are always corrupt and there are no error >messages. For floppies, all buffers must be in chip memory. -- andy finkel {uunet|rutgers|amiga}!cbmvax!andy Commodore-Amiga, Inc. "Possibly this is a new usage of the word 'compatible' with which I was previously unfamiliar" Any expressed opinions are mine; but feel free to share. I disclaim all responsibilities, all shapes, all sizes, all colors.