4 ms·

NEC did their own independent line of x86 clones. Apparently NEC V33 is 8086 with "instruction decode done by hardwired logic rather than a microprogrammed cont

by rasz 4y ago

NEC did their own independent line of x86 clones. Apparently NEC V33 is 8086 with "instruction decode done by hardwired logic rather than a microprogrammed control store. Throughput is twice as high as a V30" (datasheet claims four times faster). V30 was their clean room RE 8086 clone and was already 10-30% faster than original. V33 was used in PC-98 DO+, and in SOC form (NEC V53) in legendary Akai MPC3000, probably because Roger Linn's original LM-1 and LinnDrum were also full x86 PCs with custom cards. Sadly I cant find any place that sells V33/V53, maybe could be sourced in Japan.

EvanAnderson 4y ago
I had a laptop w/ a NEC V30 (an Ultralite PC-17-02[0]) and I recall it being a very peppy machine even compared to my father's 286. I did some assembly coding on it and I liked having the 286 PUSHA/POPA instructions. I didn't know about the 8080 emulation mode that it has, too, and it kinda makes me wish I had one to play with now. I had absolutely no idea re: the LinnDrum being a PC. That's really cool. I've never seen one in the flesh, but now I'm wondering if anybody has done conservation of the firmware. It would be a lot of fun to look at the code. [0] http://old.chuma.org/ultralite/index.shtml http://old.chuma.org/ultralite/index.shtml
- rwmj 4y ago
  Back in the day I tried running a CP/M program on the V30 alternate instruction set. It didn't work and I eventually tracked it down to the program using one of the Z80-only LDI/LDR/LDIR block instructions. You're not supposed to use those with CP/M but because CP/M ran on many UK Z80 machines like the Amstrads, inevitably real world programs did. The V30 would have been a great way to run Z80 software [in the late 1980s] if only they'd implemented these :-)
  - rasz 4y ago
    Wouldnt undefined instruction trap take care of that?
    - rwmj 4y ago
      Good question! Did V30 trap on undefined instructions? 8086 didn't according to https://retrocomputing.stackexchange.com/questions/11327/what-did-the-8086-and-8088-do-upon-encountering-an-illegal-instruction https://retrocomputing.stackexchange.com/questions/11327/wha..., but V30 was more like an 80186 which did trap, but then 8080 emulation mode might have worked differently again. Also I don't recall how I worked out that the extended Z80 instructions were causing the problem. Debugging was a lot more complicated in those days, although programs were also much smaller.
      - kens 4y ago
        I took a look at the V30 manual and it doesn't have an undefined instruction trap. It's an interesting chip, a superset of the 8086 as well as 8080 emulation. It includes bit manipulation instructions kind of like the Z80, along with multidigit BCD arithmetic. https://www.ceibo.com/eng/datasheets/NEC-V20-V30-Users-Manual.pdf https://www.ceibo.com/eng/datasheets/NEC-V20-V30-Users-Manua...
        rasz 4y ago
        V33/V53 and V33A/V53A do have them, with non A variants as non standard exception 122 http://elm-chan.org/docs/dev/v53_e.html http://elm-chan.org/docs/dev/v53_e.html mentions it. They build a cute board around it in 1998 http://elm-chan.org/works/cpu_v53/report.html http://elm-chan.org/works/cpu_v53/report.html according to MAME V40 has it as standard exception 6? https://github.com/lesbird/MAME4apple-037b5/blob/master/MAME4apple/MAME/src/cpu/nec/nec.c#L59 https://github.com/lesbird/MAME4apple-037b5/blob/master/MAME... Then again https://forum.vcfed.org/index.php?threads/nec-v20-and-cp-m.70610/post-856305 https://forum.vcfed.org/index.php?threads/nec-v20-and-cp-m.7... says no.
sacnoradhq 4y ago
I guess you haven't used octopart before: https://octopart.com/upd70136al-12-nec-10428216 https://octopart.com/upd70136al-12-nec-10428216 https://octopart.com/upd70116hcz-16-nec-18733905 https://octopart.com/upd70116hcz-16-nec-18733905 https://octopart.com/upd70116c-10-nec-2270733 https://octopart.com/upd70116c-10-nec-2270733
- rasz 4y ago
  Contacts octopart found for this part arent real distributors, they are bottom feeding speculators. No listed price means hundreds of dollars gouging aimed at military and government contractors I cant afford.
oso2k 4y ago
There's a bunch of homebrew 8088, V20, and V40 "XT" boards out there now. I bought a few related boards plus a V20 and V40 from (https://www.homebrew8088.com/ https://www.homebrew8088.com/).
- rasz 4y ago
  Yes, Im subscribed to Elijah https://www.youtube.com/@elijahmmiller/videos https://www.youtube.com/@elijahmmiller/videos
  - oso2k 4y ago
    Don’t forget the discord either.
    - rasz 4y ago
      F discord, like facebook its invisible to the outside world until you join the borg and register. Never crawled, never archived, unsearchable, undiscoverable proprietary garbage.
tenebrisalietum 4y ago
> Roger Linn's original LM-1 and LinnDrum were also full x86 PCs with custom cards. Did you mean during development? LM-1 does not look like a PC, though I think I do see the NEC CPU in these screemshots: https://www.matrixsynth.com/2014/06/vintage-linndrum-lm-1-sn-00334.html?spref=pi https://www.matrixsynth.com/2014/06/vintage-linndrum-lm-1-sn... - of course there's more to a vintage PC than an 8086.
- rasz 4y ago
  I went back to my notes. https://en.wikipedia.org/wiki/Linn_9000 https://en.wikipedia.org/wiki/Linn_9000 is 8088 PC with custom 7 slot ISA motherboard and standard ram/floppy controller cards https://www.elektronauts.com/uploads/default/original/3X/6/8/68149a3c6753c2ef67d01a1268014995bcfeb87b.JPG https://www.elektronauts.com/uploads/default/original/3X/6/8... https://www.elektronauts.com/t/the-seminal-groovebox-linn-9000-with-glitchy-samples-to-dload/45243/6 https://www.elektronauts.com/t/the-seminal-groovebox-linn-90... https://www.vintage-radio.net/forum/showthread.php?t=87739 https://www.vintage-radio.net/forum/showthread.php?t=87739 http://studiorepair.com/gallery/Linn/9000/index.html http://studiorepair.com/gallery/Linn/9000/index.html LM-1 and LM-2 were Z-80 based. Damn, cant edit my first post :( Thank you for correction.
deleted 4y ago
[deleted]

by rasz 4y ago

EvanAnderson 4y ago

I had a laptop w/ a NEC V30 (an Ultralite PC-17-02[0]) and I recall it being a very peppy machine even compared to my father's 286. I did some assembly coding on it and I liked having the 286 PUSHA/POPA instructions. I didn't know about the 8080 emulation mode that it has, too, and it kinda makes me wish I had one to play with now. I had absolutely no idea re: the LinnDrum being a PC. That's really cool. I've never seen one in the flesh, but now I'm wondering if anybody has done conservation of the firmware. It would be a lot of fun to look at the code. [0] http://old.chuma.org/ultralite/index.shtml http://old.chuma.org/ultralite/index.shtml

rwmj 4y ago
Back in the day I tried running a CP/M program on the V30 alternate instruction set. It didn't work and I eventually tracked it down to the program using one of the Z80-only LDI/LDR/LDIR block instructions. You're not supposed to use those with CP/M but because CP/M ran on many UK Z80 machines like the Amstrads, inevitably real world programs did. The V30 would have been a great way to run Z80 software [in the late 1980s] if only they'd implemented these :-)
- rasz 4y ago
  Wouldnt undefined instruction trap take care of that?
  - rwmj 4y ago
    Good question! Did V30 trap on undefined instructions? 8086 didn't according to https://retrocomputing.stackexchange.com/questions/11327/what-did-the-8086-and-8088-do-upon-encountering-an-illegal-instruction https://retrocomputing.stackexchange.com/questions/11327/wha..., but V30 was more like an 80186 which did trap, but then 8080 emulation mode might have worked differently again. Also I don't recall how I worked out that the extended Z80 instructions were causing the problem. Debugging was a lot more complicated in those days, although programs were also much smaller.
    - kens 4y ago
      I took a look at the V30 manual and it doesn't have an undefined instruction trap. It's an interesting chip, a superset of the 8086 as well as 8080 emulation. It includes bit manipulation instructions kind of like the Z80, along with multidigit BCD arithmetic. https://www.ceibo.com/eng/datasheets/NEC-V20-V30-Users-Manual.pdf https://www.ceibo.com/eng/datasheets/NEC-V20-V30-Users-Manua...
      - rasz 4y ago
        V33/V53 and V33A/V53A do have them, with non A variants as non standard exception 122 http://elm-chan.org/docs/dev/v53_e.html http://elm-chan.org/docs/dev/v53_e.html mentions it. They build a cute board around it in 1998 http://elm-chan.org/works/cpu_v53/report.html http://elm-chan.org/works/cpu_v53/report.html according to MAME V40 has it as standard exception 6? https://github.com/lesbird/MAME4apple-037b5/blob/master/MAME4apple/MAME/src/cpu/nec/nec.c#L59 https://github.com/lesbird/MAME4apple-037b5/blob/master/MAME... Then again https://forum.vcfed.org/index.php?threads/nec-v20-and-cp-m.70610/post-856305 https://forum.vcfed.org/index.php?threads/nec-v20-and-cp-m.7... says no.

sacnoradhq 4y ago

I guess you haven't used octopart before: https://octopart.com/upd70136al-12-nec-10428216 https://octopart.com/upd70136al-12-nec-10428216 https://octopart.com/upd70116hcz-16-nec-18733905 https://octopart.com/upd70116hcz-16-nec-18733905 https://octopart.com/upd70116c-10-nec-2270733 https://octopart.com/upd70116c-10-nec-2270733

rasz 4y ago
Contacts octopart found for this part arent real distributors, they are bottom feeding speculators. No listed price means hundreds of dollars gouging aimed at military and government contractors I cant afford.

oso2k 4y ago

There's a bunch of homebrew 8088, V20, and V40 "XT" boards out there now. I bought a few related boards plus a V20 and V40 from (https://www.homebrew8088.com/ https://www.homebrew8088.com/).

rasz 4y ago
Yes, Im subscribed to Elijah https://www.youtube.com/@elijahmmiller/videos https://www.youtube.com/@elijahmmiller/videos
- oso2k 4y ago
  Don’t forget the discord either.
  - rasz 4y ago
    F discord, like facebook its invisible to the outside world until you join the borg and register. Never crawled, never archived, unsearchable, undiscoverable proprietary garbage.

tenebrisalietum 4y ago

> Roger Linn's original LM-1 and LinnDrum were also full x86 PCs with custom cards. Did you mean during development? LM-1 does not look like a PC, though I think I do see the NEC CPU in these screemshots: https://www.matrixsynth.com/2014/06/vintage-linndrum-lm-1-sn-00334.html?spref=pi https://www.matrixsynth.com/2014/06/vintage-linndrum-lm-1-sn... - of course there's more to a vintage PC than an 8086.

rasz 4y ago
I went back to my notes. https://en.wikipedia.org/wiki/Linn_9000 https://en.wikipedia.org/wiki/Linn_9000 is 8088 PC with custom 7 slot ISA motherboard and standard ram/floppy controller cards https://www.elektronauts.com/uploads/default/original/3X/6/8/68149a3c6753c2ef67d01a1268014995bcfeb87b.JPG https://www.elektronauts.com/uploads/default/original/3X/6/8... https://www.elektronauts.com/t/the-seminal-groovebox-linn-9000-with-glitchy-samples-to-dload/45243/6 https://www.elektronauts.com/t/the-seminal-groovebox-linn-90... https://www.vintage-radio.net/forum/showthread.php?t=87739 https://www.vintage-radio.net/forum/showthread.php?t=87739 http://studiorepair.com/gallery/Linn/9000/index.html http://studiorepair.com/gallery/Linn/9000/index.html LM-1 and LM-2 were Z-80 based. Damn, cant edit my first post :( Thank you for correction.

deleted 4y ago

[deleted]