Assembly..

I think you'll find it is "in" and "out".

From memory, the DX register is used to pass the address of the port and AX
used for data. (you can retrive 8-bit data from AL register). I think it
goes something like.

DX = $3f8 (your port address)
AX = in(DX)
Data = AL

and..

DX = $3f8
AL = Data
out(DX)

In C it is like...

a = (inportb(STATUS) & 0xF0);

check out http://www.beyondlogic.org/spp/parallel.htm

I can check up on this later today if you have not got the info you need by
then

Regards

David Huisman

-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Andy N1YEW
Sent: Tuesday, 28 August 2001 4:05
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [PIC]: BIOS call to read from bidirectional parallel port?


Is this in assembler or c?

x=inb(port);
outb(port,x);

dont hold me to the inb and outb syntax... check it yourself...

that should work..
----- Original Message -----
From: "Harold M Hallikainen" <haroldhallikainen@JUNO.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Monday, August 27, 2001 1:58 PM
Subject: [PIC]: BIOS call to read from bidirectional parallel port?


>         I'm using PSP mode on a PIC to interface to a PC parallel port. In
the
> PC application, I'm using BIOS interrupt 0x17 to send stuff to the PIC
> thru the parallel port. My BIOS book is real old (1991) and make no
> mention of bidirectional parallel ports. Is there a STANDARD BIOS call to
> read from a parallel port?
>
> Harold
>
>
> FCC Rules Online at http://hallikainen.com/FccRules
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>
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