Grid 1520

From: Dave Mabry <>
Date: Sun Dec 12 12:11:36 2004

Ok Brian. You are making good progress. Once again, this is from the
cobwebs, but that vintage of computer didn't usually have any built-in
CMOS-setting firmware. You had to run it from a boot floppy. Don't
know, but maybe some of the more generic BIOS-setting utilities would
work. What I mentioned was that the "F" key, not F1, would force a
floppy drive boot.

The ROMS would hold whatever file size that they are. How's that for
double-speak? If the ROM is a 27010 (1Mbit) it will hold roughly 128K
bytes of files. How many slots are there under the door? I have some
of the earlier GRiDcase, the 8086-based. They have four slots that are
under the door and four internal. So you could put up to 1MB of ROMS
into that version using 27010's. On some models of Gridcase there were
internal ROM slots as well. I didn't use the 286-based versions much,
so I don't remember. There might be internal ROM slots under the
plastic that covers around the keyboard. You have to remove the display
subsystem first and to do that you have to remove the cover behind the
display. There are two screws under plastic plugs on the back panel.
Then the back cover slides back about 1/4 inch and lifts up. The
display has to be closed to do that. Then the display can lift out. Be
careful of the place that the display pivots in. That part of the
casting is easily broken. Put some white lub in that when you
reassemble it, if you take it apart. Anyway, after the display is out,
then, and only then, can you take the bezel around the keyboard off. It
snaps straight up. No screws. Then you can get to the lithium battery
used for CMOS backup. Also, if there are internal ROM slots I think you
will find the just above the keyboard, or it might be a plugin card
under the back cover of the machine.

Anyway, good luck. It is a very unique and cool system.

Brian Mahoney wrote:

> Thanks Dave! I figured it out with your help. The PS won't work when
> in the battery slot, but it will when it's a brick hooked up with the
> second power cord, the one with the barrel connectors on each end.
> However there is a bad connection inside the PS and this only works
> with pressure on one side, even then it is sporadic so I have to test
> continuity in the cord or take the ps apart and look for something
> there.
> Anyway, it boots, thank goodness, not to a prompt but until it finds a
> hard drive error which means I have to configure it. F1 doesn't seem
> to work so maybe the cmos is blank and it can't see the keyboard,
> which isn't set out like a normal board.
> It has the basic 640K plus about 1400K ram . The 100 meg drive is
> unusual and I'm dying to see what's on it. The thing that astounds me
> is that this laptop is probably nearly 16 years old and it is far
> cleaner inside than anything I use day to day. It must have been in a
> lab or never taken out of its case. The keyboard is shiny new and the
> drive area is spotless, still with the colored stickers in place.
> Pristine, really.
> Thanks again and I will post an update once I get the PS problem worked out.
> Writing to the roms seemed very interesting, I am curious as to how
> much info they would be able to hold. Did they have the capacity of a
> floppy? There is a modem inside which would be able to take care of
> data tranfer as well as the ports on the back. Tandy used roms in some
> of their models, didn't they? I mean to store applications. Acorn too,
> I think.
> All the best,
> BM
Received on Sun Dec 12 2004 - 12:11:36 GMT

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