Re: PET with 8MHz :-)

From: Matthew Hudson <>
Date: Sun, 3 Jan 2010 11:10:02 -0600
Message-ID: <>
I have the HP-IB AMIGO command set mostly implemented on the PET. I still
need to complete the DSAVE and DLOAD routines. It looks as though the
Commodore drives get very unhappy when using the parallel poll though. I
know what I have so far needs deeper debugging but I am able to read/write
to 3.5" floppies and the 15MB HD in my HP-IB drive. I have a SS/80 drive and
the command set information. If I ever get around to finishing the AMIGO
command set I'll start working on it. ;)


On Sun, Jan 3, 2010 at 10:52 AM, "André Fachat" <> wrote:

> > Since IEEE-488 is dependent upon hand shaking it should work fine.
> >
> Yes, IEEE488 relies on handshaking and the VIA whose timer is used for
> timeout is still clocked at 1MHz.
> However, I had already experimented with a 2Mhz PET version (clocking my
> selfbuilt computer with a Fat40 ROM at 2MHz) but it did not work (even
> though I modified the timeout values).
> I have also implemented IEEE488 on a number of occasions, and with the
> commodore bus it never was that simple as it should have been.
> So yes, it will probably work - but without test I don't know.
> Now the three alternatives I have:
> 1) fix my lpt-ieee488 interface - a mess of wires on breadboard...
> 2) simply us a real 4040 or 8250 drive which would involve taking the
> drives down from the attic
> 3) build an ATMEL based lpt-ieee488 replacement, using USB instead of the
> printer port...
> André
> --
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Received on 2010-01-03 18:00:03

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