#ComponentsCloseUp No. 240: PA-RISC Microprocessor
** Quick Facts! **
Manufacturer: HP
Part Number: PA-7100LC
Transistor Count: 900,000
Process Node: 0.75 μm
Year Introduced: 1994
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The PA-7100LC is a 32-bit PA-RISC (Precision Architecture Reduced Instruction Set Computer) microprocessor, and the first PA-RISC device to integrate an ALU (Arithmetic Logic Unit) and FPU (Floating Point Unit) on the same silicon die (FPU was previously a separate chip).
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The PA-7100LC would be typically paired with an MOIC (Memory and I/O Controller) chip, also known as the Viper chip, connected via the PBus. We have already looked at the Viper chip back on #CCU0170 . Click on the hashtag to see more about that part.
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To open this part, I used the pull method rather than the pry method. The last two times I’ve attempted to open these HP parts the razor blade has always slipped and scratched the silicon. This time (as recommended by @siliconinsider ) I pulled on the lid with some pliers, which made the task very easy and resulted in no damage. Like all of the other HP parts though, the silicon is covered in some jelly goop, which can sometimes make it hard to get clear photographs up close, especially as dust starts to settle on top.
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This chip contains two fantastic silicon doodles; one is the Hummingbird (the HP codename for this CPU) with the text “This Bird’s for you!!!”, and a “con artist” with a Rolex in their jacket. The “Rolex” was the name HP gave their FPU, a play on the Texas Instruments “Timex” coprocessor that was used in previous workstations.