F_Io_Control; Sf_Unlock ()4; F_Put_Byte - HP Vectra Technical Reference Manual

SF_UNLOCK (AX = 0402H)
Releases the indicated address from exclusive access.
On Entry: AH
=
F_IO_CONTROL (04H)
AL
=
SF_UNLOCK (02H)
DH,DL
=
Major and minor address (optional)
BP
=
Driver's vector address
On Exit: AH
=
Return Status Code
This is a generic put data byte function.
On Entry: AH
=
F_PUT_BYTE (06H)
AL
=
Data byte
BP
=
Driver's vector address
On Exit: AH
=.
Return Status Code
This is a generic get data byte function.
On Entry: AH
=
F_G ET_BYTE (08H)
BP
=
Driver's vector address
On Exit: AH
=
Return Status Code
AL
=
Data byte
Puts a number of bytes to a device. The difference between a buffer device and a block device is
that a buffer device accepts variable length records, while a block device accepts fixed length
records. Thus, a printer is a data buffer device and a disc is a block device. Usually, a block device
requires more parameters than a data buffer device, consequently there is a different format for
parameter passing.
Driver Writer's Guide 437