SIO Command Status ($53) ['S']

This is a command for Devices $71-$78 - The N: Device (see SIO-Commands-for-Device-IDs-$71-to-$78).

Description

For Atari, Return the status of the currently opened protocol channel, in the following format:

Offset	Description
0	LO Byte of # of bytes waiting
1	HI Byte of # of bytes waiting
2	0=Disconnected, 1=Connected
3	Extended Error code

It is expected that the buffer point to the DVSTAT location in the OS ($02EA)

Parameters

DCB	Value
DDEVIC	$71
DUNIT	$01 - $04
DCOMND	$53 'S'
DSTATS	$40
DBUF	DVSTAT
DTIMLO	$0F
DBYT	4
DAUX1	N: Status DAUX1 Values
DAUX2	N: Status DAUX2 Values

Coleco Adam Implementation

AdamNet has a specific STATUS command (which can be retrieved using the EOS REQUEST STATUS and EOS GET STATUS BYTE commands), this is used to return a bit field

bit #	Description
0	Client has data available
1	Client is connected
2	Client has an error
3	Server connection available (client is waiting)
4	Server error
5	NOT USED
6	NOT USED
7	NOT USED

Examples

Atari BASIC

REM Request Status (CMD 83 'S')
XIO 13,#1,0,0,"N:"

REM Read DVSTAT results from OS variables 746-749 ($02EA)
BW = PEEK(746) + PEEK(747)*256
CONNECTED = PEEK(748)
ERROR = PEEK(749)

PRINT "BYTES WAITING: ";BW
PRINT "CONNECTED: ";CONNECTED

ATARI

CC65

  // Get # of bytes waiting
  OS.dcb.ddevic=0x71;
  OS.dcb.dunit=1;
  OS.dcb.dcomnd='S';
  OS.dcb.dstats=0x40;
  OS.dcb.dbuf=&status;
  OS.dcb.dtimlo=0x0f;
  OS.dcb.dbyt=4;
  OS.dcb.daux=0;
  siov();

  bw=(status[1]<<8)+status[0];
  connected=status[2];

ADAM

Z88DK C

/* THIS USES EOSLIB: http://github.com/tschak909/eoslib */

#define NET 0x09
#define ACK 0x80
#define CONNECTED 2 /* second bit */

bool connected(void)
{
  DCB *dcb;
  while (eos_request_device_status(NET,dcb) < ACK);
  return eos_get_device_status(NET) & CONNECTED;
}