Post by thread:Re: [OT] need info about PC LPT port

> hi all, > > Please inform me about PC LPT port, I want to build IC programmers & > tester from PC LPT. I want to know how I can program it through PC > LPT port, in/out addresses, how to initialize, LPT mode (standard, ECP, EPP, > bidirectional), and any information about it. > > Thank You, > > Un Tung Try: http://www.lvr.com/parport.htm ---------------extract---------------------------------------- Parallel Port Central A collection of files and links to material about the PC's parallel port, including ECP, EPP, bidirectional, and IEEE-1284 modes. brought to you by Jan Axelson Basics | ECP & EPP | Chips | Cables | Programming | Other Links ------------------------------------------------------------------- Regards Cassie

part 0 363 bytes content-type:application/octet-stream; name="beyobox.zip" by Alejo Centurion, a friend of mine... :-) --------------------------------------------------------------- Content-Type: application/octet-stream; name="beyobox.zip" Content-Description: beyobox.zip (WinZip File) Content-Disposition: attachment; filename="beyobox.zip" Attachment converted: wonderland:beyobox.zip (pZIP/pZIP) (00009C7A)

Lauw Lim Un Tung wrote: > > hi all, > > Please inform me about PC LPT port, I want to build IC programmers & > tester from PC LPT. I want to know how I can program it through PC > LPT port, in/out addresses, how to initialize, LPT mode (standard, ECP, EPP, > bidirectional), and any information about it. > > Thank You, > > Un Tung Try http://www.lvr.com Miguel.

I have just looked at the LPT ports on an old PC and a newer one. Looks like the old PC used the 74LS TTL interface which means it can't source much current. A 10K load brought the 4.92V noload down to 2.52V. I can sink much more current. When the output was set at a "0" then a 1.2K from 5.0V changed the output from a 0.15V to a 0.25V. Doing the same thing with a newer computer. 3.8V --> 3.42V and 0.001V --> 0.19V. Conclusion: Don't expect to source much current on the parallel port on an older computer maybe 0.3 ma. Also the BUSY pin (PIN 11) must be forced to logical "0" to output anything. Here is the pin definition that are used by the AN589 PIC in-ckt programmers I have looked at on the internet. Pin 1 Strobe -- Not used Normally high Pin 2 D0 -- RB7(DATA to PIC) Pin 3 D1 -- RB6(CLK to PIC) Pin 4 D2 -- D0 enable not(Disables RB7) Pin 5 D3 -- PROG(Makes MCLR 12 to 13V) Pin 6 D4 -- MCLR(Brings MCLR pin low"0") Pin 7 D5 -- D1 enable not(Disables RB6) Pin 8 D6 -- Not used Pin 9 D7 -- Not used Pin 10 ACK -- RB7(DATA from PIC) Pin 11 BUSY -- ALWAYS GROUNDED Pin 13 Printer Select -- Probably needs GND Pins 18-25 GND I am making an PC LPT AN589 inckt programmer for the 16F84 PIC. I've written a program to output a one in sequence on D0 thru D7 starting with all zeros. If any of you would like it I'd be glad to share. >Date: Tue,21 Oct 1997 11:27:57 >From: Lauw Lim Un Tung <spam_OUTtungTakeThisOuTPETER.PETRA.AC.ID> >Subject: [OT] need info about PC LPT port >hi all, >Please inform me about PC LPT port, I want to build IC programmers >& tester