Apple Power Macintosh 6100/66AV

The Apple Power Macintosh 6100/66AV, based on the PDM (Piltdown Man) architecture, consists of a  case design, originally used in the Quadra 610 some 2 years earlier, allows for upgrading via a processor direct slot, into which a 90 degree NUBUS convertor can be fitted (to orientate cards horizontally). It was an upgrade to the Power Mac 6100/60, released some 6 months earlier.


The Powermac 6100/66mHz (original PowerPC) features a 66 MHz PowerPC 601 processor, 8 MB or 16 MB of RAM, a 350 MB or 500 MB hard drive, and an Audio-Visual card with S-video and RCA video input/output in a compact, desktop case. The workgroup version of the Power Macintosh 6100/66AV is the WGS 6150/66.

Legacy Support:

To support the transition from Motorola 68K CPUs to the PowerPC RISC chip, Apple created a “fat binary” disk that allowed applications to be distributed in both 68K and PowerPC formats.

Emulated applications typically run slower in the foreign machine. However, Power Macs could emulate and run 68K applications faster, because the QuickDraw graphics engine ran native in the Power Mac.


The Power Mac 6100/66AV incorporated typical ports found on 68k macs including:  ADBpowermac 6100/66 ports (Apple Desktop Bus), SCSI (25 pin DB-25), two Geoport serial ports standard (one printer, one modem), AAUI-15 Ethernet standard, S-video and RCA input/output ports provided by pre-installed AV card (not shown in image), Plaintalk microphone port and stereo sound out port. This model has both HDI-45 and DB-15 ports for video out.


This model supports one display via the HDI-45 port and another via the DB-15 port. The HDI-45 port uses 640k of system memory and supports a display at 512×394 or 640×480 at 16-bit or 832×624 at 8-bit. The DB-15 port uses the 2 MB of dedicated VRAM on the AV card and supports 512×384, 640×400, 640×480, 800×600 or 832×624 at 24-bit and 1024×768 or 1152×870 at 16-bit.

Upgrade Paths:

A number of PDS (Processor Direct Slot) daughter cards were developed.  However, the user had to sacrifice the existing AV card in the only slot on the motherboard to accomodate the upgrade.

Memory:  The 6100/66AV accepted 72 pin pin SIMMs. This model formally can be upgraded to a maximum of 72 MB of RAM, but third-parties have discovered it actually can support 136 MB with two 64 MB SIMMs and the 8 MB of onboard memory.

Hard Drive:  The PM 6100/66AV accepts 3.5 inch 50 pin SCSI hard drives (typically 7200rpm).  68 pin and 80 pin SCSI hard drives could be added but a convertor had to be used.

Introduction Date: January 3, 1995 Discontinued Date: October 14, 1995
Processor Speed: 66 MHz Processor Type: PowerPC 601
Details: This model has a 32-bit processor and a 64-bit data path.
Processor Upgrade: Third-Party* FPU: Integrated
System Bus Speed: 33 MHz Cache Bus Speed: N/A
ROM/Firmware Type: Macintosh ROM ROM/Firmware Size: 4 MB
L1 Cache: 32k L2 Cache: 256k
RAM Type: 72-pin SIMM Min. RAM Speed: 80 ns
Details: N/A
Standard RAM: 8 MB, 16 MB Maximum RAM: 136 MB*
Motherboard RAM: 8 MB RAM Slots: 2*
Video Card: Integrated, AV Card* VRAM Type: Integrated, AV Card*
Details: *This model has both integrated VRAM shared with system memory and dedicated VRAM on the AV card.
Standard VRAM: 640k/2 MB* Maximum VRAM: 640k/2 MB*
Display Support: Dual Displays Resolution Support: 640×480*
Standard Hard Drive: 350 MB, 500 MB Int. HD Interface: SCSI
Standard Optical: 2X CD-ROM (Optional) Standard Disk: 1.44 MB (Manual)
Standard Modem: None Standard Ethernet: AAUI-15
Expansion Slots: 1 601 PDS or 7″ NuBus* Expansion Bays: None*
Details: *NuBus slot available with PDS-to-NuBus adapter (M1402LL/A). By default, this expansion slot is occupied by the AV card.
Case Type: Desktop Form Factor: Macintosh Centris 610
Apple Order No: N/A Apple Subfamily: Power Mac 6100
Details: N/A
Apple Model No: M1596 Gestalt ID: 100
Battery Type: 3.6V Lithium Battery Life: N/A
Original Mac OS: 7.1.2 Supported Mac OS: 7.1.2-7.5.1, 7.5.3-9.1