🚀 go-pugleaf

n.margetic@ucl.ac.uk (Nino Margetic) writes:

>Hi,

>I am trying to write a driver for a device which accepts commands thru
>the parallel port. I have used INT17 for that, and the thing works.
>The way I've done it is simple - I am checking bit 7 after getting a
>status info of the LPT port via INT17. When bit 7 is NOT_BUSY I send a
>new character down the line.

>I know that there is also a way to access the LPT port directly thru the
>in/out commands and its 3 I/O registers. Are there any advantages (in
>terms of speed) in using interrupt driven parralel I/O, as compared to
>INT17 BIOS service as I have used it - if there is, how much, and is
>it doable in C?? I can just about read assembler, but that's about it.

>The speed of the application is crucial - I need to send as many bytes
>thru the LPT port as possible (order of 1e6). N.B. does anyone know the
>approximate number of bytes per second that can be sent thru the LPT port
>via INT17 and/or interrupt driven parallel I/O??

>Any suggestions, pointers, code snippets, anything, will be of immense value.
>Thanx in advance.

>--Nino

>--
>Janet: n.margetic@uk.ac.ucl                \     Nino Margetic         
>Earn/Bitnet/Internet: n.margetic@ucl.ac.uk  \    University College London, UK
>Bang: ...!mcvax!uknet!ucl!n.margetic         \   +44 71 387 9300 /x 53 13

I recall a byte article on this exact topic few years back. I think it
was about 5 or so. I also recal that the max baud rate you can get
is 4500. That is 4.5 KB/sec. 
--
Joseph (Yossi) Gil                 {alberta,uw-beaver,uunet}!ubc-cs!yogi
Dept. of Computer Science          yogi@cs.ubc.ca (cs.ubc.ca=137.82.8.5)
6356 Agricultural Road., Univ. of B.C.,             Tel: +1-604-822-8175
Vancouver, British Columbia, V6T 1Z2, Canada.       Fax: +1-604-822-5485