Devil's in the Details
77 Bermuda Riser
76/77 Model Codes
76/77 i/s Model Codes
9577 Multimedia Model Features
9577S Multimedia Model Features
77 5.25" Drive Bay Guides
Original 5.25" Drive Rail
5.25" 77 Drive Rail Hack
PCMCIA Adapter Mounting
76 Case Stand
SCSI Controller Sets HD as 6,1 Instead of 6,0
9577 Power Supply: 197W
9576 Power Supply: 118W
Lacuna vs. Bermuda
- Lacuna takes 4 x 16MB, Bermuda only 4 x 8MB RAM
- Lacuna has onboard IDE, Bermuda hasn't
- Lacuna has 486-Overdrive socket, Bermuda has standard-486 socket
- Lacuna has VRM (can run 3.45V cpu's), Bermuda is a straight +5V box
The easiest method to differ a Lacuna planar from any other is looking
at it from the rear (connector side). If there is a 15-pin triple-row video
connector in line with keyboard, mouse, serial and parallel - it is a "Lacuna"
planar. Bermuda Models have a 60-pin IBM RS/6000 style SCSI connector there.
9576 and 9577 Model Codes
Dxx=Choice of OS
9576 and 9577 i/s Model Codes
Thanks for showing the EASY way, Oloruin!
Axx=Lacuna, On-board IDE, built-in S3 video
All the multimedia models include the following features:
Ed. I found NO
MM 76 models.
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
There are two broad classes of box designs that led to
the 9576 and 9577.
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.
9576 Bus adapter*
9556 Bus adapter*
8556 Bus adapter*
9577i/s 5-slot bus riser assembly
9577 Bus adapter riser
9557 Bus adapter riser
8557 Bus adapter riser
type 1 85F0056
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!
The seperate riser card (riveted onto bracket) is FRU 87F4836. My HMM has the bracket/riser as FRU 87F4836. The bracket/riser is marked with a sticker as P/N 39G2063
9576i / 9577i Processor Upgrade
IBM 76 Security Cable Cover . Hmm, never seen one.
The pinout of the standard 9577 speaker/power switch module is
o IBM PS/2 8514 Display Adapter/A (#4054, 1887972)
o IBM PS/2 Micro Channel SCSI Adapter (#1005, 6451109)
o IBM PS/2 Micro Channel SCSI Adapter with Cache (#1018, 6451110)
o IBM Mwave WindSurfer-MCA Communication Adapter/A (#7058, 82G7058)
The IBM 1GB AT Hard Disk Drive (#2543, 70G8512) is supported with the following limitation: If you experience problems configuring this drive as the "master" with any other fixed disk drive in your system, reconfigure this drive as the "slave" drive.
Secured removable media via 2.88MB Electronic Eject Diskette Drive (optional)
77 5.25" Drive Bay Guides
Post- Notches on the reverse that fit into the drive bay walls.
Latch- Locks the guide onto the drive bay wall.
This was "fun". On this rail, the screw hole marked "R"
was the fixed hole, and it serves as the reference point for the important
surfaces. Note that the center-to-center distance is 3.115". Measured that
from a drive. One hole is usually slotted so there can be some variation
between mounting screw locations on drives.
5.25" 77 Drive Rail
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.
PS/2 - 76/77 S Model Configures SCSI HD As 6,1
The 9576 or 9577 system configures the harddisk with a SCSI ID of 6,1 instead of 6,0. A POST error of 1047000 107 may also occur.
Problem Isolation Aids: