u/MICOM-MINMAY

September 28th is 'Pasocom' (PC) Day because on that day in 1979 is when NEC released the PC-8001. The story is that NEC's division responsible for mainframe computers didn't see a market for "toy" microcomputers, yet the TK-80 single board kit was driving people to NEC's Bit-INN in Akihabara and emerging micom shops were demanding a personal computer to sell.

Kazuya Watanabe, Tomio Goto, and others persisted despite the pressures and criticism within their own company, and thus the PC-8001 was born. It was a huge success and was followed by the PC-6001 and PC-8801 in 1981. As for the PC-98 everyone knows and loves, the very first PC-9801 released in 1982.

For the 40th anniversary, Kazuya Watanabe told the full story (translation available):
https://youtu.be/wh7Ikcq68T8

This one arrived today and I haven't opened it or tested anything at all. The only thing I know about it is that it's able to power on but doesn't boot (which I haven't yet confirmed either). Drop your predictions and suggestions! I'll be looking into it later this evening.

Background:

Also known as a 98FELLOW, this particular model of BX (the /U2) came standard with a 20MHz 486SX, 1.6MB of memory, dual 3.5" floppy drives, and EGC graphics (so no PEGC 256-colors). Their BA counterparts were a bit more capable from the factory, having a 486DX2. It's historically worth noting that these were the first PC-9801s to sport the new NEC logo.

In their stock setup, they were suited for early Windows but nowadays they occupy sort of an awkward spot in that they lack true V30 backwards compatibility but are also below the minimum requirements for games like Touhou. However, the CPU can be upgraded, they are IDE capable, and of course can be complemented by an FM sound board. Having an external CD drive even solves the problem of not having an internal bay.

The UX21 was released in 1987 alongside the UX41 (the difference being a 20MB internal hard drive). It features a 10MHz 286, 10MHz V30, dual 3.5” floppy drives, EGC, onboard YM2203, and 640KB of memory.

Current status: This one will get all new electrolytic capacitors, both FD1137D drives are not reading and need troubleshooting, and while the exterior is pretty clean the interior has clumps of dust everywhere. The battery was removed immediately.

A finished restoration of an NEC PC-9801UV11: replaced all electrolytic capacitors, added a new Sanyo Denki PSU fan, replaced the barrel battery with a holder and FDK ML1220 rechargeable battery, both floppy drives are fully functional, and gave the entire unit a thorough cleaning.

The UV11 (released 1988) is an ultra-compact V30 machine with dual 3.5" drives, GRCG, onboard YM2203, and 640KB of memory. It can be oriented vertically or horizontally, but vertical was the default position in NEC marketing. This one had a surprise reveal of rust beneath the mainboard (unfortunately the date code had to be removed along with it). Other than that, there was no battery damage and it's fully functional.

Here is a replacement list of the electrolytic capacitors:

	μF	Voltage	Lead Spacing	Diameter	Height	Temp
Mainboard
12G1	220μF	16V	5mm	6.3mm	12.5mm	85
12H2	100μF	25V	5mm	5mm	12.5mm	105
12K2	220μF	16V	5mm	6.3mm	12.5mm	85
12K1	220μF	16V	5mm	6.3mm	12.5mm	85
12L1	220μF	16V	5mm	6.3mm	12.5mm	85
PSU (PU461)
C7	470μF	200V	10mm	22mm	37mm	105
C11	3300μF	10V	5mm	10mm	27mm	105
C12	3300μF	10V	5mm	10mm	27mm	105
C13	470μF	35V	5mm	10mm	17.5mm	105
C15	1000μF	10V	5mm	10mm	17.5mm	105
C14	100μF	25V	5mm	5mm	12.5mm	105
C17	100μF	25V	5mm	5mm	12.5mm	105
C20	100μF	25V	5mm	5mm	12.5mm	105
C16	220μF	35V	5mm	10mm	14mm	105