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Reading the NEC V20/V30 user manual[0] is like viewing a document from some bizarro world where stuff is almost like things in our world. The register naming is

Reading the NEC V20/V30 user manual[0] is like viewing a document from some bizarro world where stuff is almost like things in our world. The register naming is close, the instructions are all there but with different names, and there are a few more instructions (I can see PUSHA and POPA in there-- two instructions I loved on my 286). I've got an old V20-based NEC laptop (the PC-1702, arguably an Ultrabook in its day) and I really should dig it out and try the 8080 emulation out. It doesn't look like it'd be too difficult to execute short 8080 routines. (Getting CP/M up and going looks like more work than would be reasonable for fun.) [0] https://www.ceibo.com/eng/datasheets/NEC-V20-V30-Users-Manual.pdf https://www.ceibo.com/eng/datasheets/NEC-V20-V30-Users-Manua...

adrian_b 3y ago
NEC V20/V30 implemented the entire 80186/80188 instruction set, hence the PUSHA and POPA that you have seen. Intel 80186 had been launched in 1982, simultaneously with 80286, i.e. 2 years before NEC V20/V30, so NEC had ample time to update their instruction set. NEC V20/V30 also implemented a mode when it directly executed Intel 8080 instructions, presumably to be able to execute some old CP/M applications.
balou23 3y ago
Googling for NEC PC-1702 leads back to this post... did you misspell the model, or is just that obscure?
- EvanAnderson 3y ago
  I missed a hyphen (NEC PC-17-02) but it's also a bit of an obscure machine, too: http://old.chuma.org/ultralite/index.shtml http://old.chuma.org/ultralite/index.shtml I also mis-remembered the CPU. It's a V30, apparently. I carried mine in high school for note taking. It was a very nice little machine, albeit quirky. With no built-in mass storage aside from the "silicon disk" (2MB SRAM-based battery-backed SSD) using it was an exercise in using lightweight software.
  - EvanAnderson 3y ago
    In an odd coincidence there's a discussion about DAK on HN that popped up yesterday. That's from whom my NEC PC-17-02 was purchased. https://news.ycombinator.com/item?id=38169290 https://news.ycombinator.com/item?id=38169290 It's shown on the Spring '91 catalog cover!
NikkiA 3y ago
> Getting CP/M up and going looks like more work than would be reasonable for fun. 22NICE is still available and will almost certainly run on a PC-17-02 using the hardware 'emulation'

adrian_b 3y ago

NEC V20/V30 implemented the entire 80186/80188 instruction set, hence the PUSHA and POPA that you have seen. Intel 80186 had been launched in 1982, simultaneously with 80286, i.e. 2 years before NEC V20/V30, so NEC had ample time to update their instruction set. NEC V20/V30 also implemented a mode when it directly executed Intel 8080 instructions, presumably to be able to execute some old CP/M applications.

balou23 3y ago

Googling for NEC PC-1702 leads back to this post... did you misspell the model, or is just that obscure?

EvanAnderson 3y ago
I missed a hyphen (NEC PC-17-02) but it's also a bit of an obscure machine, too: http://old.chuma.org/ultralite/index.shtml http://old.chuma.org/ultralite/index.shtml I also mis-remembered the CPU. It's a V30, apparently. I carried mine in high school for note taking. It was a very nice little machine, albeit quirky. With no built-in mass storage aside from the "silicon disk" (2MB SRAM-based battery-backed SSD) using it was an exercise in using lightweight software.
- EvanAnderson 3y ago
  In an odd coincidence there's a discussion about DAK on HN that popped up yesterday. That's from whom my NEC PC-17-02 was purchased. https://news.ycombinator.com/item?id=38169290 https://news.ycombinator.com/item?id=38169290 It's shown on the Spring '91 catalog cover!

NikkiA 3y ago

> Getting CP/M up and going looks like more work than would be reasonable for fun. 22NICE is still available and will almost certainly run on a PC-17-02 using the hardware 'emulation'