Hi Wade,

I have done a project that sounds very similar to what you are doing. I used
EPP to a 16F877. Connected via a FIFO.

There are a lot of traps to fall into. To make it worse a lot of literature
I found was misleading.

firstly I found that the EPP port doesn't like TTL so I would try the CMOS
equivalent of the inverter.

Looks like people have given you the best links so I won't repeat them.

What platform is your host running on and what sort of data transfer are you
doing?

One thing I wish I had done earlier in my project is find out more about the
particular EPP port I was using (eg chipset,mode). This can catch you out.

Good luck, keep us posted

Darren

Darren Twiss
B.Sc.
Electronics Engineer
Hamilton
New Zealand


----- Original Message -----
From: Wade Carpenter <wade@HOME.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Wednesday, August 01, 2001 1:18 PM
Subject: [EE]: PC Parallel Port -- Issues and Inquiry


> Hello,
>
> -- Warning --
> -- Stupid question following below =)
>
> Looking for someone with good knowledge of the PC's parallel port, new and
> old computers.
>
> I am trying to interface to the parallel port, and I am having no luck -
> absolutely none.
>
> Here is what I am starting with for knowledge (assumptions?):
>
> 1) Outputs are open collector type.
> 2) Pin configuration of the port.
>
> Now some places (I.e. a certain parallel port FAQ at
> http://www.lvr.com/files/ibmlpt.txt) will tell me that the outputs are
TTL.
>
> Here's where I noticed that I'm not able to get it to work properly.  I
> tried to connect the port to a 74LS05 (Inverter) and the output and inputs
> to this chip are something like 1.3V. Total garbage.  Regardless of the
> port's state.  I do believe that the software I'm using to toggle all of
the
> outputs on the port is correct.
>
> Any ideas???
>
> Thanks,
>
> Wade
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>
>

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics