Specifications

Sound Blaster I/O Address Maps A-7
The following table lists the functions of the I/O ports on the Sound Blaster Pro that uses
the OPL3 chip:
I/O Address Description Access
Base + 0h FM Music Status Port Read
Base + 0h FM Music Register Address Port Write
Base + 1h FM Music Data Port Write Only
Base + 2h Advanced FM Music Status Port Read
Base + 2h Advanced FM Music Register Address Port Write
Base + 3h Advanced 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-11: SBPRO with OPL3 I/O Port Functions
FM music can also be accessed through I/O addresses 388h and 389h.
I/O addresses from 38Ah to 39Fh are reserved for future expansion.