@ -1324,17 +1324,20 @@ Note that not all sounds chips implement 256 volume levels. The
driver will scale the volume to the closest possible level the
chip provides.
### Function 0x52 -- Sound Pitch (SNDPIT )
### Function 0x52 -- Sound Period (SNDPRD )
| _Entry Parameters_
| B: 0x52
| C: Audio Device Unit ID
| HL: Pitch (0000=lowest note, FFFF=highest note)
| HL: Period (0000=lowest note, FFFF=highest note)
This function sets the sound chip pitch parameter. The pitch will
| _Returned Values_
| A: Status (0=OK, else error)
This function sets the sound chip period parameter. The period will
be applied when the next SNDPLAY function is invoked.
The pitch value is a driver specific value. To play standardized
The period value is a driver specific value. To play standardized
notes, use the SNDNOTE function.
### Function 0x53 -- Sound Note (SNDNOTE)
@ -1344,14 +1347,17 @@ notes, use the SNDNOTE function.
| C: Audio Device Unit ID
| L: Note (0 to 255 quarter notes)
This function sets the sound chip pitch parameter according to
| _Returned Values_
| A: Status (0=OK, else error)
This function sets the sound chip period parameter according to
standardized notes.
The value corresponds to standard musical notes. The value allows
for selection of a quarter of a semitone by giving a value between 0
The value corresponds to standard musical notes. The value allows
for selection of a quarter of a semitone by giving a value between 0
and up to the drivers maximum supported value. The lowest note is (0).
For the SN76490 chip, 0 corresponds to note A1# and the value 249 is
For the SN76490 chip, 0 corresponds to note A1# and the value 249 is
the maximum supported value, and it corresponds to note C7.
### Function 0x54 -- Sound Play (SNDPLAY)
@ -1359,9 +1365,12 @@ the maximum supported value, and it corresponds to note C7.
| _Entry Parameters_
| B: 0x54
| C: Audio Device Unit ID
| D : Channel
| E : Channel
This function applies the previously specified volume and pitch by
| _Returned Values_
| A: Status (0=OK, else error)
This function applies the previously specified volume and period by
programming the sound chip with the appropriate values. The values
are applied to the specified channel of the chip.
@ -1374,6 +1383,81 @@ HBIOS B=53 C=00 L=69 ; Select Middle C (C4) assuming SN76489
HBIOS B=54 C=00 D=01 ; Play note on Channel 1
```
### Function 0x55 -- Sound Query (SNDQUERY)
| _Entry Parameters_
| B: 0x54
| C: Audio Device Unit ID
| E: Subfunction
| _Returned Values_
| A: Status (0=OK, else error)
This function will return the status of the current pending command or
key aspects of the specific Audio Device.
#### SNDQUERY Subfunction 0x01 -- Get count of audio channels supported (SNDQ_CHCNT)
| _Entry Parameters_
| B: 0x54
| E: 0x01
| _Returned Values_
| A: Status (0=OK, else error)
| B: Count of standard tone channels
| C: Count of noise tone channels
#### SNDQUERY Subfunction 0x01 -- Get current volume setting (SNDQ_VOL)
| _Entry Parameters_
| B: 0x54
| E: 0x02
| _Returned Values_
| A: Status (0=OK, else error)
| H: 0
| L: Current volume setting
#### SNDQUERY Subfunction 0x03 -- Get current period setting (SNDQ_PERIOD)
| _Entry Parameters_
| B: 0x54
| E: 0x03
| _Returned Values_
| A: Status (0=OK, else error)
| HL: Current period setting
#### SNDQUERY Subfunction 0x04 -- Get device details (SNDQ_DEV)
| _Entry Parameters_
| B: 0x54
| E: 0x04
| _Returned Values_
| A: Status (0=OK, else error)
| B: Driver identity
| HL: Driver specific port settings
| DE: Driver specific port settings
Reports information about the audio device unit specified.
At this stage, only one driver type is supported (SN76489), but is
envisaged that more will be added in the future.
Register B reports the audio device type (see below).
Registers HL and DE contain relevant port addresses for the hardware
specific to each device type.
The currently defined audio device types are:
AUDIO ID | Value | Device | Returned registers
-------------- | ----- | ---------- | --------------------------------------------
SND_SN76489 | 0x01 | SN76489 | E: Left channel port, L: Right channel port
SND_SNAY38910 | 0x02 | AY-3-8910 | D: Address port, E: Data port
`\clearpage` {=latex}
System (SYS)
Chris Odorjan
6 years ago