| Subject: RE: Atari boot disks, how do you make them?? |
Author: Zaphod Breeblebrox (c1263766-a.casper1.wy.home.com)
Date: 08-29-2001 13:51
Okay, there is only one way to make an Atari boot-disk on a PC (2 if you want to get technical). Both require the cable for the emulators to hook the PC to an Atari Disk unit.
One is to actually run the emulator and do a format, then use the option to write DOS.SYS and DUP.SYS to the disk unit from DOS. Delete DUP.SYS (DUP=Disk Utilities Package) if you don't need DOS accessible from the DOS command in BASIC.
Okay, that out of the way, You absolutely cannot (sorry) write an Atari 8-bit SD or ED, (but have heard you can write an Atari DD, probably MFM) with a 5.25 IBM clone disk unit.
The Atari Single and Enhanced Density formats used the modulation scheme of pure FM (Frequency Modulation, quite like a 300 baud modem signal), which was very wasteful of disk surface (but cheap) and incompatible with IBM's MFM (Multiphasic Frequency Modulation, quite akin to a 1200 baud modem) modulation scheme.
Believe it or not, no disk unit actually writes bits to a disk (even 100 gig monster IDEs), it first has to put them in a modulation scheme. Then they are recorded on the flat tape of the disk drive.
Yes, even audio cassettes use a modulated scheme.
Data must be mixed in a modulator for any magnetic media to hold it. Unmodulated pulses are quite like the hiss you hear, not fitting any logical format.
Note, I did say magnetic media. CDROM usually is not magnetic (flopticals are still a mystery to me), and they use discrete bits that fit a data octet frame.
Hope it helps...
Zaphod
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