Re: apple disks in linux with fdutils

[david@uow.edu.au (David Wilson)]

justinhaynes@my-deja.com writes:
>1) What are the specifications for the floppy disk format used with the
>apple IIGS on these old 3.5" drives

800KB, 8-12 512 byte sectors per track (16 tracks per zone), 2 sides.

>2) are there any real physical differences in the way these disk drives
>deal with disks compared to drives you would find elsewhere, and where
>can I read about these differences

GCR vs MFM recording. Read Inside Apple DOS or Inside Apple ProDOS
for info on GCR (as used on Apple 140KB 35 track 5.25" disks),
any decent book on disk drives for info on MFM.

>3) Does anyone know where I can find these kinds of standards
>generally?  I tried IEEE, but couldn't find anything.

Data sheets for the early FDC chips (1790 etc from WD I think)
had much info on FM & MFM formats.

Here is my list of floppy disk formats:

disk	speed		data rate	trk	sector	trk/hd
size	rpm	s/rev	kb/s	scheme	kb	cnt*sz	count	KB
--------------------------------------------------------------------------------
8"	360	0.167	500	FM	41.67	26*128	77/1	260	SSSD (8)
8"	360	0.167	500	FM	41.67	26*128	77/2	520	DSSD (8)

8"	360	0.167	500	MFM	83.33	26*256	77/1	520	SSDD (9)
8"	360	0.167	500	MFM	83.33	26*256	77/2	1040	DSDD (9)

5.25"	300	0.200	250	FM	25.00	8*256	40/1	80	SSSD
5.25"	300	0.200	250	FM	25.00	8*256	40/2	160	DSSD

5.25"	300	0.200	245	GCR	49.00	16*256	35/1	140	SSDD (1)
5.25"	300	0.200	250	MFM	50.00	8*512	40/1	160	SSDD (3)
5.25"	300	0.200	250	MFM	50.00	9*512	40/1	180	SSDD (3)
5.25"	300	0.200	250	MFM	50.00	8*512	40/2	320	DSDD (3)
5.25"	300	0.200	250	MFM	50.00	9*512	40/2	360	DSDD (3)
5.25"	300	0.200	250	MFM	50.00	9*512	80/2	720	DSDD

5.25"	360	0.167	300	MFM	50.00	9*512	40/2	360	DSDD (4)
5.25"	360	0.167	300	MFM	50.00	9*512	80/2	720	DSDD

5.25"	360	0.167	500	MFM	83.33	15*512	80/2	1200	DSHD (4)

3.5"	300	0.200	250	MFM	50.00	9*512	80/2	720	DSDD (5)
3.5"	300	0.200	250	MFM	50.00	5*1024	80/2	800	DSDD (2)
3.5"	var	var	var	GCR	var	var*512	80/2	800	DSDD (7)
3.5"	300	0.200	250?	MFM?	50.00?	11*512	80/2	880	DSDD (B)

3.5"	300	0.200	500	MFM	100.00	18*512	80/2	1440	DSHD (6)
3.5"	var	var	var	GCR	var	var*512	80/2	1600	DSHD (A)
3.5"	300	0.200	500?	MFM?	100.00?	22*512	80/2	1760	DSHD (C)

3.5"	300	0.200	1000	MFM	200.00	36*512	80/2	2880	DSED

(1)	Apple ][
(2)	Applix
(3)	IBM PC
(4)	IBM PC/AT
(5)	IBM PS/2 25,30
(6)	IBM PS/2 > 30
(7)	Macintosh & Apple //
(8)	IBM 3740
(9)	IBM System 34
(A)	AE 1.6MB drive on Apple //
(B)	Amiga DD
(C)	Amiga HD

IBM System 34 format 256 byte sectors

	12 * 00
	3 * F5
	1 * FE
	1 * Track#
	1 * Side#
	1 * Sector#
	1 * SecLen
	2 * CRC
	22 * 4E
	12 * 00
	3 * F5
	1 * FB
	256 * data
	2 * CRC
	54 * 4E
	------
	372 bytes = 2976 bits
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia