PC Sound System Plus  (250-1701)      I/O and DMA      Faxback Doc. # 2661

Your sound card uses I/O port addresses 22xH and 24xH for data transfers,
where x has values from O to F (default is 220H).  The base address is
selectable by jumper J1 (see Page 4).

This table shows the I/O port addresses uses by the sound board.
Note that FM Music can also be accessed through I/O addresses 388H
and 89H.

ADDRESS                   DESCRIPTION                     OPERATION

200H-207H                 Game Port                        write/read
Base + 6H                 DSP Reset                        write only
Base + 8H*                FM Music (Data/Status Port)      write/read
Base + 9H*                FM Music (Register Port)         write only
Base + OAH                DSP Read Data                    read only
Base + OCH                DSP Write Data or Command        write only
Base + OCH                DSP Write Buffer Status          write only
Base + OCH                DSP Write Buffer Status(bit 7)   read only
Base + OEH                DSP Data Available Status(bit 7) read only

INTERRUPT CHANNELS:

Your sound board supports four different interrupt channels (IRQ2, IRQ3,
IRQ5, OR IRQ7) for DMA transfers.  If the interrupt channel conflicts
with other adapter cards, you can easily change the default interrupt
channel (IRQ7) on the sound board to another setting.  IRQ channels
on the sound board are selectable by jumper block JP1.

INTERRUPT                   AT MACHINE:
NUMBER

IRQ0                       Used By System Timer
IRQ1                       Used by Keyboard
IRQ2                       Free For Use
IRQ3                       Free For Use (or COM Port 2)                                  
IRQ4                       Used By COM Port 1
IRQ5                       Free For Use
IRQ6                       Used By Diskette Controller
IRQ7                       Default Used by SOUND POWER 2.0

DMA CHANNELS:

The DMA channel on your sound board is not selectable (default is DMA
channel 1).  Therefore if a channel conflict with other adapter cards
arises, you should change the DMA channels on the other cards to
another setting (DMA channel 0-3).

(jlc-10/12/93)