Format of SCSI Request Block (64 bytes):
Offset	Size	Description	)
 00h	BYTE	request number (see #01453)
 01h	BYTE	request status (see #01455)
 02h	BYTE	host adapter ID
 03h	BYTE	request flags (see #01456)
 04h	DWORD	reserved (0)
---request 00h---
 08h	BYTE	(ret) number of host adapters
 09h	BYTE	(ret) target adapter ID
 0Ah 16 BYTEs	(ret) SCSI manager ID
 1Ah 16 BYTEs	(ret) host adapter ID
 2Ah 16 BYTEs	(ret) host adapter-unique parameters (see #90010,#90011)
---extended request 00h---
 04h  2 BYTEs	(call) extended request signature 55h AAh
		(ret) if extended request supported, reply AAh 55h
 06h	WORD	(call) length of extended buffer at offset 3Ah
		(ret) number of bytes returned in extended buffer
 08h	BYTE	(ret) number of host adapters
 09h	BYTE	(ret) target adapter ID
 0Ah 16 BYTEs	(ret) SCSI manager ID
 1Ah 16 BYTEs	(ret) host adapter ID
 2Ah 16 BYTEs	(ret) host adapter-unique parameters
 3Ah  N BYTEs	extended buffer
		3Ah	WORD	features (see #01457)
		3Ch	WORD	maximum scatter/gather list length
		3Eh	DWORD	maximum SCIS data transfer size (0 = unlimited)
---request 01h---
 08h	BYTE	target ID
 09h	BYTE	logical unit number
 0Ah	BYTE	(ret) device type (see #01460)
---request 02h---
 08h	BYTE	target ID
 09h	BYTE	logical unit number
 0Ah	DWORD	data allocation length
		(ret) residual byte length (if supported and requested)
 0Eh	BYTE	sense allocation length
 0Fh	DWORD	data buffer pointer
 13h	DWORD	next request pointer (for linking)
 17h	BYTE	CDB length
 18h	BYTE	(ret) host adapter status (see #01454)
 19h	BYTE	(ret) target status (see #01459)
 1Ah	DWORD	post routine address (see #01466)
 1Eh	WORD	real mode Post DS
 20h	DWORD	SRB pointer
 24h	WORD	reserved
 26h	DWORD	SRB physical address
 2Ah 22 BYTEs	SCSIMGR$ workspace
 40h  N BYTEs	CCB, including sense data (20-24 bytes)
---request 03h---
 08h	DWORD	address of SRB to abort
---request 04h---
 08h	BYTE	target ID
 09h	BYTE	logical unit number
 0Ah 14 BYTEs	reserved
 18h	BYTE	(ret) host adapter status (see #01458)
 19h	BYTE	(ret) target status (see #01459)
 1Ah	DWORD	post routine address
 1Eh 34 BYTEs	workspace
---request 05h---
 08h 16 BYTEs	host adapter-unique parameters
---request 06h---
 08h	BYTE	target ID
 09h	BYTE	logical unit number
 0Ah	BYTE	disk drive flags (see #01461)
 0Bh	BYTE	INT 13h drive number
 0Ch	BYTE	preferred head number translation
 0Dh	BYTE	preferred sector size translation
 0Eh 10 BYTEs	reserved
---request 7Fh---
 08h	WORD	base I/O port address
 0Ah	BYTE	number of I/O ports used
 0Bh	BYTE	??? (01h returned for AHA-152x)
 0Ch	BYTE	interrupt level
 0Dh	BYTE	DMA channel
 0Eh	BYTE	(ASPI7DOS.SYS) EISA slot  number
		(ASPI8DOS.SYS) PCI device number
 0Fh	BYTE	bits 7-1: reserved (0)
		bit 0: (AHA-152x) ???
 10h	DWORD	ASPI entry point address
 14h	DWORD	previous ASPI entry point address
 18h	WORD	offset to "ASPI request dispatcher" procedure
 1Ah	WORD	offset to "interrupt handler" procedure
 1Ch	WORD	offset to some procedure
 1Eh	WORD	offset to some procedure
 20h	WORD	offset to host adapter data
 22h	BYTE	??? (apparently always 02h)
 23h	BYTE	reserved??? (0)
 24h	BYTE	(ASPI8DOS.SYS) PCI bus number?
 25h  11 BYTEs	reserved??? (0)
SeeAlso: #01462