🚀 go-pugleaf

In article <gate.4ZT6TB1w165w@toz.buffalo.ny.us>, cyberman@toz.buffalo.ny.us (Cyberman) writes:
> 
>     Pascal Roobrouck Sh53 entitled a message as 'Par pc-port bidirectional',
>    on the 11-10-92  14:05 to All.
>  PRS> I have a development kit for MCU's with a programmer that plugs into
>  PRS> the Centronics port of a PC. In the manual they say you need an AT.
>  PRS> However at home I have still an XT. The programmer software always
>  PRS> hangs on my XT when he tries to READ something from the Parallel port.
>  PRS> (a blank check..) On an AT at my office, it works fine ...
> 
>     If I remember the XT's port is implemented with some discret
>     TTL parts and the AT utilizes an 8255.  BIG difference.

The standard PC/XT parallel port is write-only, its just intended for 
driving a printer. ATs usually have bidirectional ports.
> 
>  PRS> Here my question : is there a difference in hardware between the
>  PRS> centronics port implementation in the XT and the AT PCs or is it only
>  PRS> the manufacturers 'fault'. Maybe I could buy an extra parallel port
>  PRS> for my XT that works well ??

Probably, but make sure it is a read/write port.

steve

-- 
Steve McKinty
SUN Microsystems ICNC
38240 Meylan, France
email: smckinty@france.sun.com	   BIX: smckinty