Additional Commands for R: Devices

In addition to the Atari 850 command set for R:, there are a few additional commands that have been added to the R: (0x50-0x53) devices.

$4C - Listen

Listen for TCP connections on the desired TCP port specified by aux1/aux2 (1-65535), If a port is already bound, it will be closed, and the new port specified will be bound for listening.

Value	Description
DDEVIC	$50
DUNIT	$01 (Typically $01 for R1:)
DCOMND	$4C
DSTATS	$00 (no payload)
DBUF	NULL (no buffer, because no payload)
DTIMLO	$0F
DBYT	$00 (no bytes, because no payload)
DAUX1	$LL (The low byte of the 16-bit TCP port number)
DAUX2	$HH (The high byte of the 16-bit TCP port number)

Return

If the port is opened successfully, a COMPLETE will be returned, otherwise an ERROR will result.

$4D - Unlisten

Shut down the listening socket enabled by the above LISTEN command. This will also stop any current client connection.

Value	Description
DDEVIC	$50
DUNIT	$01 (Typically $01 for R1:)
DCOMND	$4D
DSTATS	$00 (no payload)
DBUF	NULL (no buffer, because no payload)
DTIMLO	$0F
DBYT	$00 (no bytes, because no payload)
DAUX1	$00
DAUX2	$00

Return

This command will always return a COMPLETE.

$4E - Lock Baud Rate

Used after a CONFIGURE command to toggle whether to react to baud rate changes. If DAUX1=1 then any baud rate changes received via the CONFIGURE command are ignored, with a COMPLETE sent. Setting DAUX1=0 will resume normal behavior. This can be used to prevent the Atari from changing baud rate, beneficial for BBS use.

Value	Description
DDEVIC	$50
DUNIT	$01 (Typically $01 for R1:)
DCOMND	$4E
DSTATS	$00 (no payload)
DBUF	NULL (no buffer, because no payload)
DTIMLO	$0F
DBYT	$00 (no bytes, because no payload)
DAUX1	$TT ($01 = lock baud rate to prevent further changes)
DAUX2	$00

Return

This command will always return a COMPLETE.