NEC PC-8500 hacking

NEC PC-8500 is an older laptop CP/M-80 computer, last model on PC-8200 (ja) series (OEM versioned: Tandy RadioShack Model 100)

I bought it, but does not exist any information at all... I begin recording about tech information on this repo.

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Replace memory backup battery

Memory backup battery maybe dead in 2021. You can replace it located at below photo.

• Parts number: GB250H-3, but I couldn't find same battery.
• I replaced with 006P 9V NiMH battery with snap connector. Because it's popular battery form and easy to get.
  • CAUTION: You MUST replace with ONLY RECHARGEABLE battery.
  • CAUTION: You MUST DISCHARGE LOWER THAN 5V before connect. The battery backup voltage is 5V.

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Replace masked rom

PC-8500 Masked rom riser PCB (Eagle CAD)

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License

MIT (made by hand) or imported depending library supplier.

Supplier list:

• Ultra Librarian
• Snap EDA