Radio Shack TRS-80 Model II Reference Manual page 187

Technical Information
See "Handling Programmed Interrupts" for programming information.
Entry Conditions
HL
=
Address of key processing program. When
IS
pressed, control transfers to this address.
If HL
=
0, then address of previous processing program is
removed.
A 3
Exit Conditions
NZ Error
A Error Code
(HL)
=
Address of deleted
ffi~:J
key processing program, if HL
=
0 on
entry
DISKID
(function code 15)
This routine reads the diskette ID from any or all of drives 0 through 3. (The
diskette ID is assigned by the
FORMAT
and
BACKUP
utilities.) This
routine is useful when the program needs to ensure that the Operator has
inserted the proper diskette.
Entry Conditions
B Drive Select Code. If B
=
0, read from drive 0, etc.
B must be one of the following: 0, 1,2,3, or 255. If B
=
255, then
routine reads from all four drives.
(HL)
=
Buffer to hold the diskette ID(s).
HB
=
0, 1,2 or 3, then buffer must be 8-bytes long. IfB
=
255, then
buffer must be 32 bytes long. Drive
°
10
will be placed in first 8
bytes, then drive 1, etc.
A
15
Exit Conditions
The Diskette ID(s) are placed in the buffers pointed to by register-pair HL. If
a drive is not ready, blanks are placed into the buffer.
NZ Error.
A Error Code.
223