ard at p850ug1.demon.co.uk
Sun Feb 25 14:41:09 CST 2007
> Tony Duell wrote:
> > My guess, and it's only a guess, is that it works something like this :
> > At power-up, if the 9815-mode line is asseeted, the plotter goes into
> > listen mode (the HPIB talk/listen modes can be controlled from the
> ^^^^^^^^^^^ ^^^^
> > plotter's microcontroller, this is also used for self-tests on the HPIB
> > interface, as it is on the 7245...). The 9815 talks and sends it data.
> ^^^^^ ^^^^^ ^^^^
> > If the poltter gets a command that should output data (say a digitise
> > command), it goes into talk mode automatically and sends said data. The
> ^^^^ ^^^^ ^^^^^^^^^^^^^ ^^^^^ ^^^^
> > 9815 side of things knows it's just sent such a command and goes into
> > listen mode to recieve said data.
> ^^^^^^^^^^^ ^^^^^^^ ^^^^
> Good for you, you've finally got it.
Is this docuemtned anywhere? I can't see it in the 9872 operating/service
manual, but as I said I've not seen the 98130 (9815 plotter interface)
> As I said previously: un-addressed talk/listen HPIB-style data transfer.
HPIB-style, but not HPIB!. It may use the HPIB lavels, it may use the
same 3 wire handshake, but it's not HPIB if it changes direction like
that without any commands fromt he controller. That's what confused me.
You kept on insisting it was HPIB, I still claim that, strictly, it can't be.
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