Folks,

I found 6502 forums and signed up. I was Apple II and Commodore 64/128 user in 1980s.

Today I found Star Micronics NX1000 series technical manuals on manualslib website. Many Star Micronics documents are available on that website.

I reviewed that documents that comes with schematics, etc. That can now be implemented in MAME emulator and others for printer emulation to display printouts on the screen.

It said that it uses m50734sp processor (6502-based microcontroller) with 64K EPROM chip. I found that m50734sp emulation in MAME emulator.

I looked into Zimmers FTP site but found only Commodore MPS printer ROM dumps.

Does anyone have a copy of NX1000C and NX1000 rom dumps? If not, I have to find old NX1000C color printer with C664/C128 and parallel ports and make ROM dumps.

Does anyone have a copy of M50734SP user manuals? I was looking for it but only found M50734SP datasheets do not have instruction set information.

Thanks,
Tim

Welcome! Judging by the MAME source, the core is a Mitsubishi M740. You can find some pointers in this thread
viewtopic.php?p=70721#p70721

That's MELPS 740 family. And it was not only Star that used them (I mean, 6502 derived MCUs from Mitsubishi) - I remember seeing them in some photocopiers and printers when I was working in a printer workshop in mid 90's. Mita (before Kyocera bought them) even had laser printer(s) based on some more recent 740 (or maybe MELPS770 ?) family MCU.
Star LC100c that was my first printer also used some MELPS740 MCU (possibly the same); I acquired (yet another) Star XB24-250 recently (24 pin, colour, A3) and guess what is there ?
Bitsavers and Datasheet Archive have lots of datasheets, see e.g.
https://archive.org/details/bitsavers_mitsubishi
https://www.datasheetarchive.com/%22SER ... sheet.html

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