HP Vectra Technical Reference Manual page 258

On Exit: AH
=
return status
Registers Altered: AH
,... F13_RD_LSTATUS (AH = 01 H)
The status of the last disc operation performed is preserved until the next operation occurs. This
function will return the value stored as the status of the last operation.
On Entry: AH
=
F13_RD_LSTATUS (01 H)
DL
=
device number
if DL
<
80H then return flexible disc status
if DL
~
80H return hard disc status
On Exit: AH
=
Status from the last disc operation
Registers Altered: AX
Based on the supplied parameters one or more sectors are transferred from the disc into system
memory. It is the programmer's responsibility to insure that the data area provided is large
enough to contain the requested data. For the hard disc, the maximum data request is 128
sectors (at 512 bytes per sector) or 64KB of data. For the system to transfer the maximum
amount of data the programmer must supply a buffer address that is paragraph aligned (address
mod 16
=
0) otherwise the DMA Boundary error will be returned. For data requests that are less
than the maximum there are no addressing restrictions.
For the flexible disc the maximum sector request is the total number of sectors per track. This
number varies depending on the drive and media type being used (see the table in the parameter
section). Data can only be read from one track at a time. To read data from another track,
another read command must be issued with the appropriate parameters.
At least three retries of a flexible disc driver command should be made before an error is
indicated. Each retry should be preceded by a reset command, i.e., F13_RESET_DISC.
Disc 249