Common Power
Models 35 / 56 / 76 Power (118W PSU)
Models 40 / 57 / 77 Power (197W PSU)
Front Panel Connector Pinout
Cases, Planars, and Riser Cards
Unit does not turn on (9556/57 9576/77)
PCMCIA Adapter Mounting
Front Panel Connector Pinout

|
Pin |
Description |
Pin |
Description |
1 |
PWR LED (-) |
5 |
PWR LED (+) |
2 |
HD LED (+) |
6 |
PWR Sense (+) |
3 |
HD LED (-) |
7 |
Audio (-) |
4 |
PWR Sense (-) |
8 |
Audio (+) |
|
Warning: The pin numbering may be incorrect (needs
verification)!
Note: The matching pin header may have
more pins than the plug in some cases. The later planars typically have 12-pin
header, but they are still compatible with the 8-pin plug. Both the header and
the plug are keyed to ensure correct installation.
Cases, Planars, and Riser Cards
You can upgrade any current PS/2 56/57 or 76/77 with
the later "Lacuna" Planar. You'll gain all the advantages of the new 76/77
i and s systems. Current 76/77 systems will perform up to 38% faster while
keeping everything else intact.
Note: Models 35 and 40 are ISA-based,
and can't be upgraded with a MCA planar (the chassis is slightly different).
There are two case sizes designed to accept the same planars:
3x3 case:
8556 → 9556 → 9576 → 9576i (IDE) & 9576s (IDE + SCSI)
5x5 case:
8557 → 9557 → 9577 → 9577i (IDE) & 9577s (IDE + SCSI)
The 855X had a planar based around the 80386SX or 80386SLC CPU.
The newer 955X system were 486SLC2/SLC3 based. The first 9576 and 9577 systems
used the same system board known as "Bermuda"
(built-in SCSI). The later 9576/9577 i/s systems used a different board - called
"Lacuna" (built-in IDE) and were
available in two different clock speeds - 25 and 33 MHz.
The 76s/77s systems were the same as the 76i/77i units but they
were equipped with a (modified) Future Domain SCSI card, to handle internal/external
SCSI devices.
These models used the following riser cards (largely non-interchangeable):
Type | # Slots | Part Description | FRU P/N |
8556 (386SX/SLC) | 3x 16-bit (1x AVE) | Bus adapter | 79F7210 |
Bus adapter/speaker support | 79F7213 |
8557 (386SX/SLC) | 5x 16-bit (1x AVE) | Bus adapter riser type 1 | 85F0056 |
Bus adapter riser type 2 | 41G3877 |
plus adapter support guide | 92F0042 |
9556 (486SLC2/3) | 3x 16-bit (1x AVE) | Bus adapter | 79F7210 |
plus bus adapter support | 96F7769 |
9557 (486SLC2/3) | 5x 16-bit (1x AVE) | Bus adapter riser card | 41G3877 |
plus adapter card guide | 96F7758 |
9576 ("Bermuda") | 3x 32-bit (1x AVE) (1x BVE) | Bus adapter | 87F4833 |
plus bus adapter support | 96F7777 |
plus card guide/speaker assembly | 92F0244 |
9577 ("Bermuda") | 5x 32-bit (1x AVE) (1x BVE) | Bus adapter riser card | 87F4836 |
plus adapter card guide | 92F0042 |
9576 i/s ("Lacuna") | 3x 32-bit (1x AVE) | Bus riser assembly | 68G2706 |
plus card guide | 92F0244 |
plus card guide assembly C2 | 92F0243 |
plus bus adapter support | 71G5711 |
9577 i/s ("Lacuna") | 5x 32-bit (1x AVE) | Bus riser assembly | 68G2709 |
plus card guide | 92F0042 |
plus card guide assembly C2 | 96F7758 |
Note: The CMOS battery (CR2032) is located on the
riser card for all listed systems.
So you see, it is important to know both the part number
and clock speed limitation of the Lacuna-type board, and to have the correct
bus riser card for the particular box/system board. In other words, you
cannot really upgrade a 76/77 to a 76/77 i/s without changing the riser card
as well as the system board!
Unit does not turn on (9556/57 9576/77)
Certain (Premium Line) models 9556, 9557, 9576 and 9577 have a security
switch and will not run with the cover removed or if there is some problem
with the switch.
The Security switch is built into the front of the base unit and interrupts
the power-supply. It's easy to find - it is blue and sits somewhere left from
the disk-drive bay.
It can be pushed with the finger gently upwards and to the inside -
and the machine *should* run fine even without the case cover.
No need to be afraid: both - the power-switch as well as the security switch -
operates at low voltage. They switch only a +5 V sense-line, not mains voltage.
But watch out: sometimes the security
switch flips back after some time or when you accidentally bump into the system.
Result: the machine switches off immediately again. This is pretty annoying,
especially when you have just 95 percent of some software installed
(or even worse, of your hard-drive formated)...
The same switch is sometimes defective, after rude, careless people violently
push the case over the machine - or stuff the machine into the cover
respectively. It breaks and the machine won't power on.
If you are experiencing a machine, which does not power on, inspect this
switch first, before you begin replacing parts like planar or power-supply.
PCMCIA Adapter mounting
I finally got around to installing the PCMCIA adapter in my
77s. The trick- mount the adapter on a 76/77 floppy tray. (Adapter MUST
be in the stamped metal bay PN 64F1270) Remove the rail guides on the dive
support structure in the 77. (Catches are on the inner end) swap the guides
to the other side and push them onto the mounting studs. Now turn the
tray/adapter upside down and push it into the rails. Note that the two card
ejection buttons are now on the left side of the adapter. Just happens to be
the exact height to perfectly fit the bezel.
|