Function 43

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dooright

Joined: 08 Dec 2004
Posts: 1

dooright 10 Dec 2004, 04:41

I am trying to learn how the Menuet program communicates over RS-232 by studying the source code to ppp.asm and terminal.asm. Unfortunately, the part I want to understand has an undocumented system call, #43.

Is there some reason this call is not included in the API docs? If it were to be included, how would it be defined?

10 Dec 2004, 04:41

spideros1

Joined: 17 Jan 2004
Posts: 77
Location: Poland

spideros1 10 Dec 2004, 07:23

it's sys_outport system call. someone has probably forgotten to add it to documentation.

10 Dec 2004, 07:23

Madis731

Joined: 25 Sep 2003
Posts: 2139
Location: Estonia

Madis731 10 Dec 2004, 10:07

Anyone looking this thread - knowing how to call 43 - please post us some documentation.

Maybe one with enough power could update manuetos.org with this document. Smile

10 Dec 2004, 10:07

spideros1

Joined: 17 Jan 2004
Posts: 77
Location: Poland

spideros1 10 Dec 2004, 10:43

43 = SEND DATA TO DEVICE
bx=port
cl=data
return:
eax = 0 if OK
otherwise error

10 Dec 2004, 10:43

mike.dld

Joined: 03 Oct 2003
Posts: 235
Location: Belarus, Minsk

mike.dld 10 Dec 2004, 10:49

Code:

43 = SEND/READ DATA TO/FROM DEVICE

     OUTPUT:

     bx  : port #
     cl  : data

     result : eax = 0 if OK, error code otherwise

     INPUT:

     ecx : port # (31st bit must be set)

     result : eax = 0 if OK, error code otherwise
               bl = data

Before any I/O operations, port (or group of ports) must be reserved (and freed when no longer needed):

Code:

46 = RESERVE/FREE PORT AREA

     ebx  0 reserve
          1 free
     ecx  port area start
     edx  port area end

     result: eax = 0 if OK,
                   1 if error.

_________________
http://ostin.googlecode.com/

10 Dec 2004, 10:49

profkid13

Joined: 21 Aug 2003
Posts: 111

profkid13 23 Dec 2004, 08:31

spideros1 wrote:

43 = SEND DATA TO DEVICE
bx=port
cl=data
return:
eax = 0 if OK
otherwise error

how comes not all the functs are in sysfuncs.txt?

and shouldnt it be cx = port and bl = data ?:p

23 Dec 2004, 08:31

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