https://arstechnica.com/gadgets/2023/05/brand-new-laptop-recreates-1981s-ibm-pc-complete-with-8088-cpu-and-640kb-of-ram/
Un nuovo portatilino basato sull'8088... Mah. Per un paio di centoni di USD.
Cose carine: slot CF (che funge da HDD) e USB, possibilità di un 8087, bus ISA (8 bit) disponibile per espansioni (schede) tramite dongle.
Notare in calce all'articolo l'aggiornamento con la segnalazione che il BIOS parrebbe essere stato piratato da un progetto open source (GPL).
Personalmente, la cosa più interessante sono i commenti; ne riporto qualcuno:
«
Eigenvogel
The fact that this is sold by a CNC company might be a hint. There's a niche market for DOS systems to run machine tools, lab equipment, etc. that have proprietary ISA interface cards. Back in the day I can remember trying to help people scrounge up old motherboards for such beasties. Such equipment can cost six or seven figures so there's often pressure to keep using it even if it's technologically obsolete.»
«SeanJW
vonduck said:
640k? that much? sure they didn't mean 64k?
1981 PC was available with 16k to 64k. XT was available up to 256k. But the expansion slots allowed up to as much RAM as you could stuff in it (just short of 1M because of the ROM at the top)
However the big caveat with that "as much as possible" is that IBM (not Microsoft or anyone else) reserved the top 384k for I/O expansion. Specifically, the segments at 0A000H and 0B000H were both reserved for video memory. The CGA never used more than 16K of the memory at 0B800H, and the MDA used 4K at 0B000H.
I'm mildly disappointed they didn't at least stick an EGA in there - they could have used 640x350 in 16 colours out of 64 then. The EGA did use 0A000H (in planar graphics modes), and used 32K of 0B800H in CGA style modes.
And note the lack of overlap with the MDA and anything else? Yes, you could stick an MDA alongside any colour graphics card and have dual-monitor setup on the original IBM PC (as long as you disabled the parallel port - both the CGA and MDA provided the printer port at 0x3BC). It was essential if you were a Windows programmer in the early days, as a debugger ran its output on the MDA and debugged Windows programs ran on the graphics card. It was important for a simple reason - nothing could capture the EGA state, switch it to its own, then restore it back when the program was running. The EGA was full of write-only registers.»
(Z80 vs i808x)
«SeanJW
Thomas Harte said:
… and then we saw segmented real-mode x86 and wondered how many legions of middle-managers it’d taken to committee out the requirements on that.
Nah, 8086 is clearly derived from 8080 - so much so that porting software could literally be loading a set of macros for 8080 instructions that mapped through to equivalent 8086. That was an important thing. Part of why MS-DOS APIs mapped through to CP/M ones and the COM format is identical. A portable CP/M program could just be macro translated, and boom, instant MS-DOS program. NEC took it to the next level with its 8080 binary mode.»
«watermeloncup
I was wondering about the USB port too, but then noticed that the spec sheet says "USB (CH375B)". That's actually a really cool chip which I've only recently found out about. It provides USB host support for simple 8-bit microcontrollers as well as DOS. Combined with a simple .sys driver, you can use USB mass storage devices like thumb drives in DOS. That would make exchanging files with this system super easy.
ISA cards with this chip are all over eBay for just $30. I haven't got one myself, but apparently it works pretty well once you find the right driver.»
CYA