Power Computing Power 100 / 120-series


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The PowerPC 601-based Power 100/120-series shipped with 8MBs of DRAM preinstalled on its logic board (aka "Cold Fusion"). Using this logic board's six vacant 72-pin SIMM expansion slots, the maximum amount of DRAM addressable by these computers is 200MB, attainable by installing six 32MB SIMMs, according to Power Computing technical documents.

Like the Power Mac 8100 upon which it is based, this logic board accepts an L2 cache in sizes of 256k, 512k, or 1MB, though it should be noted that only 256k and 512k pieces were offered by Power Computing. A 1MB L2 SIMM that works in any NuBus Power Mac, including the 6100, 7100 or 8100, should also work in this machine.

This early Power Mac clone, known internally as "Yetti," shipped with a PPC601 microprocessor running at either 100MHz or 120Mhz, and a logic board bus running at 40Mhz. WIth three NuBus slots, and one processor-direct slot (PDS depicted in the drawing above as "I/O Card Slot"), this logic board also featured two SCSI buses, an internal bus rated at 10MB/sec, and an external bus rated at 5MB/sec.

Like other Power Macs of its generation, Yetti was readily dual-monitor capable, with logic board video circuitry and support for optional 2MB or 4MB Apple HPV (High-Performance Video) or Apple 2MB (nonupgradable) AV PDS graphics cards, though many machines shipped without them. It is noteworthy that Power Computing shipped machines lacking PDS video cards with PDS terminators in the PDS slot, and like other Power Macs of this generation, this logic board requires either a terminator or a PDS graphics card to operate properly. Some Apple technical documents suggest that logic board damage is possible in the event the computer is operated with an unterminated PDS bus.

While the microprocessor is soldered onto the logic board, and hence not upgradable, Sonnet has introduced a line of G3 daughtercards that install in the I/O Card slot. Upgraders should determine whether they own a model with a PDS graphics card, as as the Sonnet upgrade must be installed into the PDS slot, and an 8100 AV/Video Adapter will also be required.

Note: The Power 100's High-Speed Memory Controller (HMC) requires memory SIMMs to be installed in pairs. Like other Power Macs, the Cold Fusion-series has a 64-bit internal memory path. Since 72-pin SIMMs are only addressable 32-bits at a time, they must be installed in matched pairs. When purchasing DRAM upgrades for the Power 100, please ensure you purchase two at the same time. For best results, SIMMs used should have common chip sets, and come from the same manufacturer.

Specifications:

Logic Board RAM		8MBs Soldered
Supported SIMMs		4MB, 8MB, 16MB, 32MB
Number SIMM Slots		Eight (8)
Number VRAM Slots		None
L2 Cache Supported?		L2 SIMM: 1MB
SIMM Type		72-pin, 32-bit, 80ns or faster

While some of the products mentioned on this page may no longer be available, the information about these products remains available to those who may need it.

Since the Power 100/120-series optionally shipped with a 2MB or 4MB VRAM PDS Video Card or a 2MB Audio-Visual (AV) Card in its PDS slot, additional VRAM configurations than those indicated by the table above are consequently possible.

Please be advised that the codeword link above points to a page on Jeff Keller's PowerWatch website, and the microprocessor link to a page in Motorola's awesome website.