Topic       : The ATARI Compendium
Author      : Scott Sanders / JAY Software
Version     : 1.25 (20/6/2003)
Subject     : Documentation
Nodes       : 1117
Index Size  : 32614
HCP-Version : 6
Compiled on : Atari
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View Ref-FileGiaccess()
Ongibit()
Offgibit()                                                            XBIOS

Syntax

VOID Offgibit( mask )
WORD mask;

Function      Offgibit() clears individual bits of the sound chip's Port A.

Opcode        29 (0x1D)

Availability  All TOS versions.

Parameters    mask is a bit mask arranged as shown below. For each of the
              lower eight bits in mask set to 0, that bit will be reset.
              Other bits (set as 1) will remain unchanged.

              Name           Mask   Meaning

              GI_FLOPPYSIDE  0x01   Floppy side select

              GI_FLOPPYA     0x02   Floppy A select

              GI_FLOPPYB     0x04   Floppy B select

              GI_RTS         0x08   RS-232 Request To Send

              GI_DTR         0x10   RS-232 Data Terminal Ready

              GI_STROBE      0x20   Centronics strobe

              GI_GPO         0x40   General purpose output (On
                                    a Falcon030, this bit controls the
                                    state of the internal speaker)

              GI_SCCPORT     0x80   On a Mega STe or TT030, calling
                                    Ongibit( 0x80 ) will cause SCC
                                    channel A to control the Serial 2
                                    port rather than the LANLocal Area Network
. To select
                                    the LANLocal Area Network
, use Offgibit( 0x7F ).

Binding       move.w   mask,-(sp)
              move.w   #$1D,-(sp)
              trap     #14
              addq.l   #4,sp

See Also      Giaccess(), Ongibit()