Bermuda Planar

7677ref.exe Model 76/77 Reference Disk v3.10 (zipped image)
rf7677a.exe Model 76/77 Reference Disk v1.1 (zipped image)
7677diag.exe Model 76/77 Diagnostic Disk v3.11 (zipped image)
rd7677a.exe Model 76/77 Advanced Diagnostics v1.1 (zipped image)

192-223 PS/2 76/77, Ultimedia M77, and 486-33/66 Microprocessor Upgrade Option

486 Interposers and Upgrades

ECP Support
Direct Cable Connection under 95

Bermuda Planar (9576/77)
System Firmware
   ROM Images
Bermuda Versions
Bermuda Riser Cards
Built-in SCSI
Bermuda Overclock

Bermuda Planar

SX: FRU P/N 39G2668 [P] or 39G5698 [P] [P] | [P] [P] or 87F4839 [P]
DX2: FRU P/N 39G2669 or 39G6086 [P] [P] | [P]

J1 Mouse port
J2 Keyboard port
J3 Parallel port
J4 DE9 Serial port A
J5 DE9 Serial port B
J6 SCSI connector (mini-C60)
J7 Internal SCSI header (50-pin)
J8 Pads for 4-pin SCSI diag. header
J9 SIMM Socket 4
J10 SIMM Socket 3
J11 SIMM Socket 1
J12 SIMM Socket 2
J13 Riser Card Slot
J14 Pads for 3-pin header (Speed)
J15 Pads for 3-pin header (?)
J16 Floppy Connector (44-pin)
J17 Power Supply Connector (P1)
J18 Power Supply Connector (P2)
J19 Front Panel Connector
J20 Pads for 8-pin header (LogicLock?)
J21 JMP2 Pads for 3-pin header
J22 JMP1 Power-On Password
J23 EEPROM prog. pads (solder side)
OS1 25.0000 MHz osc (SCSI)
OS2 32.0000 MHz osc (SCSI 80C188)
OS3 22.1184 MHz osc (UART)
OS4 Pads for 50 MHz osc
OS5 66.0000 MHz osc (CPU Bus)
OS6 24.0000 MHz osc (FDC)
OS7 40.0000 MHz osc
OS8 14.3181 MHz osc (adapters)
R14 PTC fuse (KB/mouse?)
R31 PTC fuse (SCSI?)
ST1,2 Resistor Networks
U12 N80C188-16 MCU (SCSI busmaster)
U14 CXK5864BM-10LL 8Kx8 SRAM (NVRAM)
U15 Dallas DS1285 RTC/CMOS
U19 SRM20256LM-12 32Kx8 SRAM (SCSI MCU)
U20 ST M27C512 SCSI microcode 39G2066
U23 HM514280ALJ8 256Kx18 DRAM (SCSI cache)
U24 84F8324 SCSI bus controller
U28 Dallas DS1210S NVRAM controller
U31 33F6715 SCSI MCA iface/BM DMA controller
U32 15F6903 SCSI Cache/data flow controller
U42 10G4672 I/O controller
U48 QFP 486SX (SX) or pads only (DX2)
U49 Socket 1 for 486DX
U52 ST93C46A 1kbit Serial EEPROM
U60 64F8781 Memory Data Buffer
U65 ST M27C1001 (BIOS 39G3299)
U76 82077xx Floppy controller
U78 89F5724 Memory controller
U79 89F5415 MCA Buffer/Controller?
U84 63F7520(ESD) DMA controller
Y1 32.768 KHz xtal (RTC)

U76 This can be either a 82077AA, 82077SL, or NS PC8477AV-2 floppy controller. Planars with the 82077SL controller are rather rare and have the U65 System EPROM 39G3299 soldered directly to the planar (no PLCC socket).

Early versions of the board (39G2668 and possibly 39G2669) lack two additional 74xx ICs (U85 and U86) near the silver-capped IC (U84) and have a bunch of bodge wires.

J8 - SCSI Diagnostic Port

1RXD (U32 pin 45)
3N/C (key)
4TXD (U32 pin 93)

Not populated. The port can be used to access the Serial Console.

System Firmware (POST & BIOS)

Simplified firmware stored in EPROM. IML image required for the system to operate.

ROM Images

39G3299 - 03 Aug 1992, rev. 3, 1x 27C1001 PLCC32 (U65)

Bermuda Versions

There were several versions of the "Bermuda" board:

  • (39F2668) 486SX (25/33 MHz jumperable) with "Upgrade CPU" socket
  • (39G2669) 486DX (33 MHz only) with CPU in the "Upgrade socket"
  • (39G5698) 486SX-33 MHz
  • (39G6086) 486DX2-33/66 MHz
  • (39G6444) 486DX2-33/66 special bid for Pinnacle CD-ROM Bootable Systems

Bermuda Riser Cards

Bermuda 76 Riser FRU 87F4833

The 76i bus adapter support (individual FRU) is 61G2289. FRU 87F4833 is for the bracket alone.

BT1 CR2032
J1 32-bit MCA slot with Base Video Extension (BVE) (for XGA/XGA-2...)
J2 32-bit MCA slot
J3 32-bit MCA slot with Auxiliary Video Extension (AVE)

Bermuda 77 Riser FRU 87F4836 [P]

The separate 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

BT1 CR2032
J1 32-bit MCA slot with Base Video Extension (BVE) (for XGA/XGA-2...)
J2 32-bit MCA slot with Auxiliary Video Extension (AVE)
J3-5 32-bit MCA slots

Onboard SCSI

From Peter (edited):
   The onboard SCSI is functionally the same as the Spock Prime and from the most part uses the exact same components. The 512 KB cache is implemented using a single non-removable DRAM device. The SCSI BIOS is part of the machine BIOS stored in a single EPROM. The SCSI code also included in the IML image.

If you look closely at the 9577 planar you will find some SMD transistor "of the bigger kind" and some stuff that looks like auto-termination. In addition the onboard SCSI adapter is described as "SCSI-2 compliant"... which extends on the command set in the first place, the enhanced SCSI translation and on the electric interface as well I think. But not on the speed of course, which is 5 MB/s SCSI-1 standard.

From IBM:
   The SCSI controller is integrated in the planar so a slot is not required.
   Supports SCSI Common Command Set Version 4.B (SCSI-2 Compliant), Attachment of up to 7 SCSI physical devices (internal and external), Allows multiple SCSI initiators for device sharing, SCSI Data Transfer Rate - up to 5.0 MB/sec, Supports Synchronous and Asynchronous SCSI Data Transfers, Supports disconnect/reconnect of SCSI targets, Automatic external SCSI bus detection (disables internal planar terminator automatically), Slew rate controlled SCSI drivers and filtered SCSI receivers for high data integrity.

Bermuda Overclock

From Peter Wendt:
   I tried the oscillator swap (Ed. OS5 80.000 MHz) on a "Bermuda" - with less success so far. The system tries to come up but lands in a number of errors, from which the "trivial ones" (162/163/161) are logically a symptom of the board removal and a total loss of CMOS contents. But the machine comes up with a I9990021 - even with a proper ref-disk in A: it chokes on reading any other floppy. Guess it is the same problem as with the Mod. 90/95.

I tried running the machine with a DX4-33/100 in 2x mode (jumper on interposer), which is known to even work at 50MHz input clock. No go. The cursor in the phase before memory count seems to blink a bit faster... but then the machine hangs with I999-error after the count. Configuring it properly and *then* swapping the oscillator (which is a bit tricky) did not work either - ran into a solid I999 0022 (invalid IML). Restoring system partition from diskettes also failed.

Conclusion: overclocking isn't a good idea, at least not with this. Any other experiences?

CPU Upgrades

DX4100-ODPR works.
   I bought an Evergreen 586 CPU upgrade with an AMD P133 chip on it. It made my PS/2 77 (9577-0UF) go noticeably faster, perhaps 15 to 25 percent quicker. No incompatibility problems - but McAfee Office still rates my machine as a 486-33 (go figure!).


Bermuda BVE Slot

On the 9576, Slot #1 is the BVE Slot, Slot #3 is the AVE slot.

Bermuda Planar ADF

Serial Port One: Choices are Serial 1 through Serial 16, or disabled. Standard interrupt levels are IRQ 4 for serial 1 and IRQ 3 for any other serial level.

Serial Port Two: Choices are Serial 1 through Serial 16, or disabled. Standard interrupt levels are IRQ 4 for serial 1 and IRQ 3 for any other serial level.

Parallel Port: Choices are Parallel 1 through 4 or disabled.
Note: IBM used a different IO address for LPT1 of 03BC-03BF instead of the common 0378-037B. You may be better off to set your parallel port to PARALLEL 2.

PARALLEL 1 (03bc-03bf 1278-127b int 7), 2 (0378-037b int 7), 3 (0278-027b int 7), 4 (1378-137b int 7), Disabled

Parallel Port DMA Arbitration Levels:
   If the level is shared then other devices can use the same level. If the level is dedicated then only this device can be set to that level.
   Shared Level 7 - 0, Dedicated Level 7 - 0, and Disabled.

SCSI Address (ID): ID of the built-in SCSI controller. Choices are ID7 through ID0. Under normal circumstances, select <7>.

SCSI I/O Address: Select: I/O address of built-in SCSI controller.
   <3540h-3547h>, 3540-3547, 3548-354F, 3550-3557, 3558-355F, 3560-3567, 3568-356F, 3570-3577, 3578-357F

SCSI Fairness On/Off: Choices are On or Off. Bus Arbitration Fairness controls whether the adapter will release control of the bus when it has been using it exclusively. Under normal circumstances, select <On>.

SCSI DMA Arbitration Level: Choices are Level 1, 3, 5 through E. Selecting an arbitration level allows only this device to use the value.

ADP Fields (System determined)

Alternate Processor: Type of CPU installed in alternate processor socket on system board.

Current System Speed: Current speed of the system, 25MHz or 33MHz.

System Board: System board type

Content created and/or collected by:
Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

Ardent Tool of Capitalism is maintained by Tomáš Slavotínek.
Last update: 08 May 2024 - Changelog | About | Legal & Contact