[rescue] little SCSI hard drives

[Mike Hebel]

MF> I saw through something the other day that the 500 series battery is a
MF> "smart" cell, with circuitry on flex strip; if you can open the battery
MF> without damaging the circuit then you can get a 9.6V RC car pack, nicd or
MF> nimh as the original batteries require, both are available; swap the
MF> polarity on the top two cells and install the thermistor between them and
MF> you're ready to go with something like a 1.5 hour battery.

My this sounds familiar... ;-)
*as mike looks through his sent items to the Powerbooks list*

Ni-Cad were never used in the 500 series batteries - they were all
NIMH.  Doing the above conversion you end up with a 1200mah battery
instead of the 1750mah but it seems to come out the same amount of run
time - about an hour per battery.  To get more you'd need to order
1800mah 1.5V cels from specialty outlets which will cost considerably
more than the RC pack.  For the record the original battery pack
contained 6 1.5V NIMH AA size cels and 2 1.4V AA size cels for 11.8V
total - _very_ odd.  Also be careful soldering the laminated circuit
as they're hard to repair.

MF> I have (loosely, it's on loan) a 520... watch carefully your top hinges,
MF> though they're repairable if you don't mind 4 screw heads poking through the
MF> back of the screen, as the plastic bosses crack away from the metal hinges
MF> they can be drilled out and cross-bolted.

True but make sure that the front microphone cover can still be
snapped back into place if you have it.  Totally flat headed (pan
head?) bolts would be best.  Also washers - the plastic is that
brittle.  If your's are in good condition make sure you remove the
"bullet" hinge covers and tighten the two screws regularly as these
being loose are the cause of the stress in the case cover which causes
the plastic to break.

MF> Great ittle machines, though AFAIK the flavors of linux and BSD do not work
MF> for them because of the lack of a coprocessor and some circuitry changes
MF> over a regular mac. YMMV. I ran OS 8.1 on mine and it was nice and speedy, I
MF> could even run a quicktime movie, looked terrible though, 4 bit greyscale.
MF> external SCSI works well with a $30 adapter and an ACTIVE terminator.

Actually Debian 68k works on it but does not support Ethernet yet
though there is a patch in the works.  NetBSD does support the onboard
Sonic ethernet though and seems to run ok but I'm not sure if it
supports sound.  Personally I run MacOS 7.6.1 on mine with booters for
NetBSD and Debian 68k to run on an external drive until I decide what
I really want to run.  Oddly enough there are notes out on the web
about getting OS X to run on this box even in 68k flavor.  YMMV -
heavily!

MF> last but not least, do some studying on the PCMCIA adaptor's revision or
MF> serial numbers, back when I was looking for one I found there are two
MF> revisions of those, one's quite flaky. This is information from roughly 14
MF> months ago, so again, your mileage may vary.....

You want the Rev C adapter if you ever want to be able to run the PPC
upgrade CPU in the machine.  The others should be fine for non-PPC
use.  None of them are supported under 'nix yet though.

Mike                         mailto:nimitz at owc.net

http://drone8of9.crosswinds.net/documents/Mike_Hebel_Current_3.html

http://drone8of9.crosswinds.net/documents/Mike_Hebel_Current_3.doc