From matz@kawo2.rwth-aachen.de Sun Feb 02 02:58:00 1997
Newsgroups: comp.sys.atari.8bit
Subject: SIO-Protocol/Comands
From: Matthias Belitz <matz@kawo2.rwth-aachen.de>
Date: Sun, 02 Feb 1997 02:58:00 +0100

Hallo !


Whole development-time of our IDE-Controller I had to deal with the 
possible SIO-Commands diskdrives would accept. Now I have the idea to 
collect all the possible commands and figure out, which drives will 
support it - so I want to designe a list of it.

This is what I figured out at this time, please send your remarks:

-------------------------schnip----------------------------------
$52	R	Read sector
$50	P	Write sector
$57	W	Write sector with verify
$53	S	get controller status, returns 4 bytes
	byte 0	drive status
		bit 0 - Command frame error
		bit 1 - Checksum error
		bit 2 - Operation error
		bit 3 - Write protect
		bit 4 - Motor on
		bit 5 - double density
		bit 6 - unused
		bit 7 - Dual (medium) density
	byte 1	controller status, returnd values are inverted
		bit 0 - busy
		bit 1 - drq
		bit 2 - lost data
		bit 3 - crc error
		bit 4 - record not found
		bit 5 - record type
		bit 6 - write protect
		bit 7 - not ready
	byte 2 time-out (format); $e0
	byte 3 unused; always 0
$21	!	format disk (single for 810 and stock 1050)
		as defined by CMD $4f for upgraded 1050 and XF 551
		(heard, that they will give back 128/256 bytes?)
$22	"	format enhanced (medium, dual) density (1050)

This was the standard command set of 1050 (810) drives

$4e	N	read drive configuration; returns 12 bytes
	byte 0	number of tracks [1 for harddisks)
	byte 1	step rate
	byte 2	sectors/track high (total number for harddisks)
	byte 3	sectors/track low 
	byte 4	number of heads decreased by one
	byte 5	format (0=FM; 4=MFM)
	byte 6	bytes/sector high
	byte 7	bytes/sector low
	byte 8	drive activated
	bytes 9-11 unused
$4f	O	write drive configuration; see above
$3f	?	get high-speed-index
		Happy, US-Doubler, HDI (Germany) return $0a
		Speedy (Germany) returns $09
These are supported by all double density drives.

Special Speedy (Germany) commands:
$20		format automatically, acts like $21, but computer has 
not to wait till drive is ready
$51		stop write command, writes all data from internal buffer 
to disk, stop motor then
$44		configure drive/track display
$4b		configure slow/fast
$4c		direct jump command for internal processor of 1050
		jumps to location stored in DAUX,$30a
$4d		jump, as above, but drive sends a "COMPLETE" bevore 
jumping
$41		add/remove command to/from internal command table
$68		get length of internal high-speed-SIO-subroutine
$69		send high-speed-SIO-routine to computer
$60		write track, writes complete track
$62		read track

US-Doubler:
$66		format disk with special sector-skew	
-------------------------schnap----------------------------------

Thanx, Matt
-- 
         | | |                 __________________________________
         | | |                /                                 /
         | | |               /                                 /
        /  |  \             /email: matz@kawo2.rwth-aachen.de /
       /   |   \           /  belitz@genesis.rwth-aachen.de  /
      Atari 8-bit         /                                 /
power without the price  /_________________________________/

    http://www.kawo2.rwth-aachen.de/~matz/atari/index.html