Reference and Diagnostic Disks
Bermuda Planar (9576/77)
   Bermuda vs. Lacuna Risers
   Built-in SCSI
   Bermuda Overclock
Lacuna vs. Bermuda
   Upgrading Planars
   Devil's in the Details
77 Control Module Header Pinout
76/77 Power Supply
PCMCIA Adapter Mounting
76 Case Stand
   AVE Slot

Bermuda vs. Lacuna Riser Card
   If you think you can just drop a Lacuna into a Bermuda system, you are wrong. The riser cards have physically different edge contacts. Note the edge connectors. The 76i bus adapter support (individual FRU) is 61G2289. This FRU is for the bracket alone. 

Bermuda Riser FRU 87F4833

BT1 CR2032 
J1 Base Video Extension slot (For XGA/XGA-2) 
J2 32 bit slot 
J3 Auxiliary Video Extension slot 

   Note the "BVE" like connector at the left (rear) of the riser. As Bermudas do not have on-board video, the riser needs a BVE slot. This riser has the spring clips just like the Lacuna riser. 

Lacuna RiserFRU 68G2706 

BT1 CR2032 Battery 
J1 Auxiliary Video Extension slot 
J2, J3 32 bit  slots 
SC Spring Clip- presses up against bus adapter support 
     Note the lack of a "BVE" connector on the Lacuna riser edge. 

Upgrading planars
  You can upgrade any current PS/2 76/77 or PS/2 56/57 with the new PS/2 Planar Upgrade. 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. 

Devil's in the Details
From  Carlyle Smith

   There are two broad classes of box designs that led to the 9576 and 9577. 
Narrow box:
8556 --> 9556 --> 9576 --> 9576i (IDE) and 9576s (IDE plus SCSI) 

Taller box:
8557 --> 9557 --> 9577 --> 9577i (IDE) and 9577s (IDE plus SCSI) 

Of course, the 855X were 80386DX or 80386SLC, so they used a completely different system board. The 9576 and 9577 used the same system board (=Bermuda), one with SCSI built into the board (=Bermuda). The 9576i and 9577i (Lacuna system board) were made in  two different clock speeds -- 25MHz and 33MHz.  Their system board FRU part numbers were: 

    25MHz only:  95G9691 (not  streaming transfer capable) 
    25<-->33MHz switchable 96G1305 
    33MHz : 95G9692 

   A 957Xs is only a 957Xi with a modified Future Domain SCSI card added to one of the adapter slots on the bus riser card, to handle internal/external SCSI devices. 
   The models used the following riser cards (non-interchangeable, AFIK)(* means CMOS battery located on riser card): 

Parts Comparison:
    9576i/s  3-slot bus riser assembly    68G2706
             plus card guide              92F0244
             plus card guide ass'y C2     92F0243
             plus bus adapter support     71G5711

    9576     Bus adapter*                 87F4833
             plus bus adapter support     96F7777
             Plus card guide/spkr ass'y   92F0244

    9556     Bus adapter*                 79F7210
             plus bus adapter support     96F7769

    8556     Bus adapter*                 79F7210
             Bus adapter/spkr support     79F7213

    9577i/s  5-slot bus riser assembly    68G2709
             plus card guide              92F0042
             plus card guide ass'y C2     96F7758

    9577     Bus adapter riser card       87F4836
             plus adapter card guide      92F0042

    9557     Bus adapter riser card       41G3877
             plus adapter card guide      96F7758

    8557     Bus adapter riser type 1     85F0056
                            or type 2     41G3877
             plus adapter support guide   92F0042

   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 957X to a 957Xi/s without changing the riser card as well as the system board! 

   I do not know how to verify the riser and bracket stuff. If you know what bracket/riser will or won't work with a Lacuna, tell ME!

IBM 76 Security Cable Cover . Hmm, never seen one. 

77 Control Module Header Pinout
The pinout of the standard 9577 speaker/power switch module is 
PWR Sense +
Audio -
Audio +

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 stucture 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. 

9576 Case Stand
  This is for all you long suffering (and unfortunately cpu starved) 9576 owners. But cheer up, there is hope. I had a CPU stand from a PC350 laying around. I looked at my 76. Looked at the hook arrangement on the stand. Tried it a few ways. Click! Click! 
   Please note that the stand is attatched to the side of the system WITHOUT the power supply.

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