Diacom plus on Pentium laptops

[TBK]

The C3 uses either the CE lamp (12V) or Serial 160 output 5V. P4 8192 is 5V.
The Diacom cable buffers the signal, so output voltage is not the reason
they use the parallel port. It is the best way to simulate a software uart,
control the DIAG line modes and talk to three different hardware systems:

C3 CE lamp
C3 Serial 160
P4 Serial 160
P4 8192

Rinda crammed all of that into the circuit board in the cable.

-----Original Message-----
From: Ken Kelly <kenkelly at lucent.com>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Tuesday, July 28, 1998 1:15 PM
Subject: Re: Diacom plus on Pentium laptops


>The Diacom software runs on the Parallel port so it doesn't
>use a Uart. They use the Parallel port because the ALDL port
>does not have RS-232 voltages. You must use a level
>converter to convert the 0 to 5 volt signal to +/- 10 volts.
>Diacom uses the serial data link in the Parallel port
>because it has 0-5 volt levels. They do there own timing
>control.
>
> Ken
>
>mrvette wrote:
>>
>> Am I illiterate here on the latest and greatest?  I somehow thought that
UART's
>> solved that problem long ago....?    GENE
>>
>> TWong29770 at aol.com wrote:
>> >
>> > I so far found that I can communicate with earlier ECM's.  However I
still
>> > cannot talk to a 94 GM truck PCM, or my 95 OBD1 PCM in my Corvette.  I
can
>> > talk to both PCM's while using a 486 slower computer.  Rinda tells me
it's the
>> > clock speed of the CPU's conflicting with the communication rate of the
>> > ECM/PCM's.
>> >
>> > Weird....
>> >
>> > Tom
>