HP Vectra Technical Reference Manual page 447

This is a generic put data buffer or put data block function. Either a string write or a disc block
write could use this function.
On Entry: AH
=
F_PUT_BUFFER (OAH)
CX
=
Data byte count or block count
ES:DI
=
Pointer to data buffer
BP
=
Driver's vector address
On Exit: AH
=
Return Status Code
Writes a fixed block of data to a block device.
On Entry: AH
=
F_PUT_BLOCK (OAH)
DH
=
Major number
DL
=
Minor number
ES:DI
=
Command Block
Word 0,1: Data transfer address
Word 2: Block count
Word 3: Block address LSW
Word 4: Block address MSW (for some devices this word is ignored).
BP
=
Driver's vector address
On Exit: AH
=
Return Status Code
BX
=
Operation status
This is a generic get buffer or get block function. Either string reads or disc block reads could use
this function.
On Entry: AH
=
F_GET_BUFFER (OCH)
CX
=
Byte count or block count
DS:SI
=
Pointer to data buffer
BP
=
Driver's vector address
On Exit: AH
=
Return Status Code
438 Driver Writer's Guide