π―π΅ NEC PC-8201: Part 2 (Year 1983 to 2025 change) [TCE #0567]
32Let's do a little bit more ... let's patch the cold boot date from 1983 to 2025 and also look how the internal 64KB RAM upgrade is supposed to work - can I make a daughterboard to make it simple?
I'm not sure how I'm going to transfer files at the moment - might need to use the serial port ... but need to expand the RAM first and replace the internal 3.6V NiCd backup battery.
00:28 ... Engineering Undergraduate Society (EUS) of the University of Queensland (UQ)
02:28 ... Looking at the interface ports
04:50 ... ROM & RAM expansion bay
06:10 ... Default cold boot date: 1983/01/01
08:10 ... Opening up the machine
12:30 ... Patching the ROM (N82 BASIC)
16:05 ... Removing the internal NiCd battery (with Engineer SS-03 solder sucker)
18:28 ... Figuring out the (future) RAM upgrade
20:35 ... Patched cold boot date: 2025/01/01
22:00 ... Converting battery pack to re-chargable
24:05 ... To be continued
25:15 ... Channel thanks & Outro
Patch the year & century:
https://www.web8201.net/default.asp?content=NECY2K.asp
Converting the standard AA battery pack to rechargeable - not convinced I got it working ...
https://www.web8201.net/default.asp?content=NiCadMod.asp
32KB RAM upgrades:
https://www.web8201.net/default.asp?content=MemoryModules.asp
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From Part 1:
I finally got my hands on one of these Kyocera-built machines that use the Intel 8085 processor. This is (obviously) NEC's implementation with 16KByte of RAM, running N-82 BASIC and sporting a rather fetching colour scheme.
I managed to get it quite cheap (via buyee.jp) as it has two busted key caps. There was, coincidentally, also an auction for a spare keyboard, although not the matching colour. So, for now, I've replaced the missing key caps with cream coloured ones ... will need to keep my eye out for a busted red PC-8201, preferably with missing keys and thus technically cheap, so I can match the colour for those two missing keys.
There's two things I want to do immediately:
[1] The machine has three banks of RAM, two of which are internal. I think they can be upgraded to 32KBytes each which will give me 64KByte of RAM. The max is 96KBytes apparently if the cartridge slot is used.
[2] Patch the ROM so that the date reads "20xx" rather than "19xx".
I got the idea for patching the century from here:
https://www.web8201.net/default.asp?content=NECY2K.asp
Of course, plenty of other things to do ... figure out Option ROMs and which ones I should install and loading some software. It looks to use the same 8-pin DIN at the PC-8001 for the cassette (CMT port).
It also has a floppy disk port ... not sure how that works ... I'm guessing it's similar to the PC-8001 and Commodore ... the actual disk unit has some intelligence (i.e. CPU) and thus can't simply be replaced by a Gotek.
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