Specifications

A-6 Sound Blaster I/O Address Maps
SBPRO I/O Address Map
Sound Blaster Pro uses base I/O address 220h or 240h. These are jumper selectable.
Base Address I/O Addresses Used
220h 220h to 233h
240h 240h to 253h
Table A-9: SBPRO I/O Ports
There are two versions of Sound Blaster Pro. The difference is in the FM chip used.
The earlier version uses a two-operator FM (OPL2) chip, while the later version uses
a four-operator FM (OPL3) chip.
The following table lists the functions of the I/O ports on the Sound Blaster Pro that
uses the OPL2 chip:
I/O Address Description Access
Base + 0h Left FM Music Status Port Read
Base + 0h Left FM Music Register Address Port Write
Base + 1h Left FM Music Data Port Write Only
Base + 2h Right FM Music Status Port Read
Base + 2h Right FM Music Register Address Port Write
Base + 3h Right FM Music Data Port Write Only
Base + 4h Mixer chip Register Address Port Write Only
Base + 5h Mixer chip Data Port Read/Write
Base + 6h DSP Reset Write Only
Base + 8h FM Music Status Port Read
Base + 8h FM Music Register Port Write
Base + 9h FM Music Data Port Write Only
Base + Ah DSP Read Data Port Read Only
Base + Ch DSP Write Command/Data Write
Base + Ch DSP Write-Buffer Status (Bit 7) Read
Base + Eh DSP Read-Buffer Status (Bit 7) Read Only
Base + 10h CD-ROM Command or Data Register Read/Write
Base + 11h CD-ROM Status Register Read Only
Base + 12h CD-ROM Reset Register Write Only
Base + 13h CD-ROM Enable Register Write Only
Table A-10: SBPRO with OPL2 I/O Port Functions