Path: utzoo!utgpu!water!watmath!clyde!att!ucbvax!XEROX.COM!"Robert_L._White.ESXC15"
From: "Robert_L._White.ESXC15"@XEROX.COM
Newsgroups: comp.sys.atari.st
Subject: 5.25 help
Message-ID: <880721-140208-4503@Xerox>
Date: 21 Jul 88 20:50:04 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 27

Hi, I just FTP'ed the schematic for the step doubler.
Program 40_80_tr.pi3
I have some questions though.
	1) what exactly does this do? i.e. does it double the step pulse from
		one pulse to two pulses, or lenghten the step pulse.

	2) must you use a hi density 5.25 (1.2 meg) to use the 80 track 		feature?  I
didnt think the standard 5.25 that an IBM uses 		would do 80 tracks.


I currently have a 5.25 hooked up, but have several problems. I have changed the
memory locations required to make the step pulse 6ms but still I have problems.

The problems are:
		1) I cannot format the 5.25 under pc-ditto 40 track, it fails.
			The drive seems to do a lot of stepping.
		2) I have written a "c" program to format for 40 tracks, and 			that works
with no problems (no errors returned), 			except that I get allot of disk errors
when reading or 			writing. i.e. data on disk may be damaged, cancel,retry.
Sometimes a retry will work, but not allways.
		3) The really strange thing is, when I format a 5.25 on a PC, I 			have no
problems reading or writing to that disk on my 
			5.25 drive on my ST. Wierd!

Any help would be nice
Thanks
Bob White, Xerox corp.