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MiniSport Laptop Hacker 05
MiniSport Laptop Hacker - Vol 5, 3 Dec 1992
Yea! I've gotten a few more technical responses from the audience. I'm
never sure what people are most interested in. Usually a discontinued, but
useful computer attracts a cadre of hackers to support it. I initiated
this series in an effort to provide a single point resource point. Keep
sending the tech info!
On the flip side, I'll bet there are a lot of first-time MS-DOS users who have
purchased this machine because of its "out of production" cost. Let me know
what information you need to make this thing useful in your Amateur Radio
quests. Owning it is only half the battle. Be sure to *use* it to its full po-
tential.
>>>DISASSEMBLY INSTRUCTIONS Remove the battery. If you'll do more than
remove the back panel, I suggest removing the Li batteries, too. If you re-
move the main battery pack and the Li batteries, you'll loose all RamDisk info
and configuration info. Back it up first!
There are 12 phillips screws holding the back of the computer in place. Re-
move the 5 around the perimeter of the bottom. Notice that one rubber foot
has no screw. So as to not snap plastic, remove the 2 screws holding the
modem cover in place. Remove the modem cover. Loose the 4 scres holding
the handle of the computer. I leave these in place as the back panel is lifted
off. Lastly, don't forget the single screw on the back panel (not bottom). It
is the one farthest from the flip down access panel on the back.
Once all 12 screws have been loosened or removed, lift the back cover
straight up. The oval Li battery cover will remain in place. There's a plastic
insulating sheet attache to the inside of the bottom cover. Be sure not to
dislodge or crease it as you lay the back cover aside.
Another dozen screws allows the circuit board to come up. For reference, lay
the computer upside down with it's back toward you. Remove the 3 screws
across the top (the front edge as it lays). The two metal brackets on each
side are held down by two screws each. Remove these 4 screws, as you no-
tice the orientation of the metal brackets. Right in the center, there is a sin-
gle screw holding down a grouding tab. Remove the 1 screw, and the tab if
it appears to be loose. The next 3 screws are *inside* of the flip down ac-
cessory panel on the back. They're tiny. Don't loose them! The last screw
actually is one of four that mount the disk drive in place. It must be taken
out to loosen the silder and copper colored grounding straps that curl up
around the right side of the circuit board between the power switch and the
disk drive.
Disconnect the ribbon cable that overlays the copper colored foil you just
loosened. *Carefully* note how the power switch, the ribbon, cable, the fer-
rite choke (if present), and the disk drive are arranged. This is the most
difficult part to get alligned correctly during reassembly.
As you lift the lower right side, depress the power switch so you don't break
it off! The eject button of the disk drive also needs to be pressed in as it
passes past the thin plastic strip of the computer case blocking its path. The
power switch and disk eject button need to be caressed during reassembly,
too, simultaneous with holding the ribbon cable and ferrite choke on the cable
in place. Do you have three hands?!
While rotating the entire board a little clock-wise (to release the plastic clip
extending out from the battery enclosure), lift the left and front upward. The
circuit board and the keyboard will be free. The keyboard must be lifted out
at the same time or the green acetate ribbons curling around the left side of
the circuit board will be strained. *Although the keyboard and the circuit
board are not connected, they must be handled as one unit while the acetate
ribbon cables are connected*
As you lift out the keyboard/circuit board pair, you'll find they're still con-
nected to the rest of the computer on the back (bottom as you look at it). I
find it convenient to open them like a clamshell and set the computer on its
side. It stands up all by itself like a birthday card.
>>>POWER PINOUTS
More info on dissembly next time if folks are interested. For now, back up to
when you just pulled the back panel off.
Just below the center circuit board hold-down screw, there is a double row of
8 pins (bottom view of a 16pin mini Scotch flex connector header). Pin 1 is
toward the right and front of the computer. As you look at it:
15 13 11 9 7 5 3 1 1 2
16 14 12 10 8 6 4 2 or rotate CCW: 3 4
5 6
A working power supply provides the 7 8
following voltages: 9 10
11 12
1: 5.1 2: 5.1 13 14
3: 0.0 4: 5.1 15 16
5: 5.1 6:-22.1
7: 10.3 8:-10.4 When my system quit working, it consistently
9: 0.0 10: 6.6 failed with the following indications:
11: 0.0 12: 5.1 pin 5: 0.0
13: 0.0 14: 0.0 pin 6: 3.9
15: 5.1 16: 5.1 pin 10: 5.7
Well, I have gone way over my self-imposed one page length! Oh, by the way,
if you're looking for an excellent "cram it all onto paper" utility that lets you
document packet work, consider tcols, distributed with the shareware A86 as-
sembler. I'm currently evaluating version 3.21 (off of CDROM, available to you,
as indicated in MLH Vol4). Tcols appears to be a unix clone, accepting param-
eters of line width, length, number of columns, etc. I run my printer at 160
characters per line (12cpi condensed) and pack in 8 lines per inch. That's
how I archive all the good info you folks send me.
Next time, MINIMUM BOOT FILES, BOARD REVISIONS, and more DISASSEMBLY
and PINOUTS.
73, Brian, ka9snf@wb7nnf.#spokn.wa.usa or Internet ka9snf@jupiter.spk.wa
