Workgroup Server 8150

Essentially this is Power Mac 8100 with a few modifications. First of all, while almost all of 8100 Macs came with a 2MB video board in its PDS slot, this one has no video board, only a built-in circuitry is used. To make the system stable, a PDS terminator board should be put into PDS slot. The 110MHz (in earlier versions 80MHz) PowerPC 601 CPU was sufficient for powering services for a small Macs network in 1994 when it was released. The hard drives started from 500MB to 2GB. Built-in RAM was still 8MB, expandable by 8 72-pin SIMMs. The network could be built using AAUI and transceivers or a network board in NuBus slot. It came with System 7.5 line, probably with some server extensions.

Model No: M1688

Year: 1994
Discontinued: 1996
CPU: PowerPC 601 80MHz
later: 110MHz
RAM: 136MB (4x32 SIMM)
+8MB (onboard)
Max. RAM: 264MB?
RAM Type: 8x72-pin SIMM
Hard disk: 2GB SCSI, 3.5" SL
(originally 1GB)
Also delivered with 500MB
Floppy drives: 1 1.4M 3.5"
Other drives: Apple SCSI CD-ROM drive
Graphics: 1MB VRAM, built-in, Apple's "high-density" connector.
Sound: Speaker, headphone/Mic
Display: External, 45-pin HD45 connector
Dedicated OS: Mac System 7.1
Maximum OS: Mac System 9.1
Expansions:  - ADB.
 - 4 SIMMs for RAM Expansion
 - 3 NuBus slots
 - PDS slot

Photo from before 2020

Connectors:  - 45-pin video connector
 - External SCSI port (DB25)
 - AAUI network card connector
  - 2 serial ports (RS-422) for modem and printer)
- ADB connector for keyboard and mouse
 - Sound output
 - Microphone in

Origin of my unit is not known. Although I suspected a graphics studio, there were stickers all around referring to different companies, so it is possible that it was passed between different second-hand computer retailers. It came in a quite bad condition, now it is restored into more or less working state but it's still incomplete - some front covers are missing.

Although the mainboard has been repaired, the termination board for multimedia expansion slot is missing so it is not stable and sometimes it does not even boot to desktop. Usually a multimedia/video board is present and it terminates a system bus. Otherwise, a board with capacitors and resistors on some lines is present to make bus stable. According to some sources, running with PDS slot unpopulated may even damage the mainboard. - Power Mac 8100 mainboard - Apple's technical specifications