On 17-May-99, Tony Duell wrote:
> Does the interface also specify how to communicate
with devices? I
No, unfortunately. All the specification describes is
how to transfer
bytes between the devices (well, and a lot more, but it's at that sort
of level). It doesn't describe what the devices are to do with those
Too bad. I guess I'll have to keep scavenging for genuine GRiD GPIB
devices, or find a machine that can hook up to the Compass and _not_
need to be the master, and figure out how to program it to do something
useful (not very easy).
Any ideas what the Grid is expecting?
Nope. Apparently GRiD did sell their own GPIB peripherals. Whether or
not they are compatible with HP's devices I have no idea. More likely
HP than CBM, though. :)
Doug (Yowza) Salot mentioned that he had an external GRiD GPIB 10MB hard
drive that he was trying to access, back in March 1998 (yes, I've combed
the ClassicCmp archives looking for GRiD info). Interestingly, the post
was called "GPIB + disk drives" and you (Tony) posted about the
GPIB/IEEE-488/HPIB standard. Seeing as the other Doug is more than a
year ahead of me in his search, I should probably contact him. :)
Also, John Higginbotham apparently had some of his Compass manuals on
the web at one point, but they've been removed. :/
It's funny how none of the GRiDdites read this list anymore.
> I don't have the cabling to do this,
unfortunately, else I would have
> already tried. I only have the PET-to-IEEE-488 cable (the PET uses
> an edge connector). The connector on the 2040, of course, is the
> same sex as the GPIB connector on the GRiD.
That's the standard GPIB connector (a 24 pin
Amphenol, a bit like a
cut-down Centronics port). The cables have a plug and socket at each
end so you can stack them to link up multiple devices.
Yup, I had noticed that. Quite handy. But I don't have the cables to
make use of this, I only have the single cable that connects to the PET.
> >There have been 'mailboxes' to go
between 2 separate GPIB systems,
> >but they're not that easy to find.
> Heh. Probably an understatement. :)
Look out at radio rallies. I did find a GPIB extended
device to allow a modem link to sit between 2 parts of a GPIB bus)
for \pounds 2.50 a couple of months back. 'Mailboxes' might well
Radio rallies == Hamfests are not easy to find themselves, and the only
one I've attended (some two hours away by bus) was very small and not
well populated with computer gear, unless packet-modemed VIC-20s,
TeleVideo terminals, and lunchbox '286 machines at three-times Salvation
Army prices are your thing.
I'm hoping to attend one of the big fleamarkets soon, to see what turns
> >But the Grid should be able to talk to CBM
disk drives and
> Without additional software?
No, alas. Well, the printer might work, but remember
that CBM printers
don't use ASCII, so you'll have to translate the characters.
Actually, I don't have an IEEE-488 printer (unfortunately). For a while
we had no printer, and then we got an Oki and PET-to-Centronics adapter
which did the translation (if needed).
In a moment (day?) of madness a few years back I
modified the ROMs in
a CBM 4023 to make it accept ascii to use it with my PERQ...
I don't think the gods will curse you for this mod. :)
And actually, you could buy ROMs for some printers to change their
character sets. The Oki we had, had the ROMs replaced so that it would
print using PETSCII. But that may have been in the C64 era.
I don't know where that printer is ATM. My brother must have it (it was
his printer, but he's got a PC with one of those Canon bubblejets now
and he probably wouldn't be USING the Oki).
I use my HP LaserJet 4L with my PET these days. :) Which reminds me,
I've been wanting to fix the program I use to print BASIC source
listings to work with upgrade ROMs...