The "hardware", IIRC, that you'd need is if you needed the /SS (Slave
Select) signal provide my most SPI I/Fs, although I've simulated the /SS
signal without additional hardware. (Note: You might, however, want to trhow
in a couple of buffer chips to isolate the PC's parallel port from damage;
once you pop the usually buiilt-in parallel port circuitry, repairing your
motherboard or laytop might be difficult!)

Douglas Wood
Software Engineer
dbwood@kc.rr.com
ICQ#: 143841506

Home of the EPICIS Development System for the PIC
http://epicis.piclist.com

----- Original Message -----
From: "Spehro Pefhany" <speff@INTERLOG.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Thursday, February 06, 2003 6:15 PM
Subject: Re: [OT]: Re: SPI emulator software for PC?


> At 06:04 PM 2/6/2003 -0600, you wrote:
> >None that I've edver found. I have, however, written several applications
> >that "bit-bang" the parallel port to talk to SPI interfaces (this is how
> >many AVR processors are prograamed in-circuit using software like
PonyProg).
> >Be aware that this technique requires an additional "kernel-level driver"
in
> >the NT-series of Windows products (NT/2000/XP) do to the protected nature
of
> >I/O on those operating systems. Windows 3.1/9x/Me do not require this
> >software and you can fiddle with the parallel port pretty easily.
>
> I don't think SPI slave is possible without some extra hardware, but
> SPI master should be a simple matter of bit-banging to the port (through
> whatever driver is required by the OS).
>
> Note that *some* SPI devices don't allow you to indefinitely delay
> between bits, so even a master may be a problem in some situations.
>
> Best regards,
>
> Spehro Pefhany --"it's the network..."            "The Journey is the
reward"
> speff@interlog.com             Info for manufacturers:
http://www.trexon.com
> Embedded software/hardware/analog  Info for designers:
http://www.speff.com
>
> --
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