lai@vedge.UUCP (David Lai) (08/02/88)
I originally posted a message re: using the Kodak 6.6M floppy disk drive in comp.sys.amiga. I now have new information on it, and seeing it is getting a little more technical, I've moved it to .tech. The drive looks like it'll work with the amiga except for 1 thing, the motor speed is 600 RPM (about twice the speed of the amiga's 3.5"). The data timing I beleive is the same (500 ns. per bit, MFM), however the index pulses now arrive at 100ms intervals. The question is: can the Amiga's internal disk controller (part of a custom chip), be able to handle reading and writing tracks at 600rpm ... or is too much hardware/software dependant on the slower speed (360 rpm, 166ms) drives.? Is the index pulse used at all? If so, will the electronics sync up to 100ms index pulse intervals? Can any hardware types at C-A comment? Kodak does sell an IBM-PC controller for their drive, but the last thing I want to resort to is using the PC bus of the 2000 (and kludging something to interface the amiga bus to the PC bus). -- "What is a DJ if he can't scratch?" - Uncle Jamms Army The views expressed are those of the author, and not of Visual Edge, nor Usenet. David Lai (vedge!lai@larry.mcrcim.mcgill.edu || ...watmath!onfcanim!vedge!lai)
grr@cbmvax.UUCP (George Robbins) (08/04/88)
In article <423@vedge.UUCP> lai@vedge.UUCP (David Lai) writes: > I originally posted a message re: using the Kodak 6.6M floppy disk > drive in comp.sys.amiga. I now have new information on it, and seeing > it is getting a little more technical, I've moved it to .tech. > > The drive looks like it'll work with the amiga except for 1 thing, the > motor speed is 600 RPM (about twice the speed of the amiga's 3.5"). The > data timing I beleive is the same (500 ns. per bit, MFM), however the index > pulses now arrive at 100ms intervals. The question is: can the Amiga's > internal disk controller (part of a custom chip), be able to handle > reading and writing tracks at 600rpm ... or is too > much hardware/software dependant on the slower speed (360 rpm, 166ms) drives.? > Is the index pulse used at all? If so, will the electronics sync up > to 100ms index pulse intervals? The built-in disk controller function in the Amiga chipset is limited to the standard 3.5" floppy data rate. Anything faster has to either have a SCSI interface, or you either have to go thru the PC bus or design your own controller card. -- George Robbins - now working for, uucp: {uunet|ihnp4|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@uunet.uu.net Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
bryce@cbmvax.UUCP (Bryce Nesbitt) (08/05/88)
In article <423@vedge.UUCP> lai@vedge.UUCP (David Lai) writes: >The drive looks like it'll work with the amiga except for 1 thing, the >motor speed is 600 RPM (about twice the speed of the amiga's 3.5"). The data rate is the important factor. >The data timing I beleive is the same (500 ns. per bit, MFM)... That number looks suspicious. If the Kodak is the same data rate (250K BPS, 250ns pulses, 4 microseconds between pulses) then you are in business. In this case the Amiga would see it as a 90mm (3.5") drive with lots of tracks. >however the index pulses now arrive at 100ms intervals. >Is the index pulse used at all? No. Not for what you want. >How much hardware/software dependant on the slower speed (360 rpm, 166ms) >drives.? That's 300 rpm, 200ms drives. >Can any hardware types at C-A comment? Ooops! I'm a software type, take that all back :-) >David Lai (vedge!lai@larry.mcrcim.mcgill.edu || ...watmath!onfcanim!vedge!lai)