Thanks! It looks like the PcW16 is not so rare as I thought.
Is there any emulator for it? I have only a CP/M version of the pi-calculator. It is a PI-GENERIC3.COM file for CP/M from my archive. It uses a CP/M+ standard call to get a value of a timer but the accuracy of this call is very low, only seconds. So it is worth to run the program for 100 (or even 1000) digits several times and get the average. If there is an emulator for the PcW16 somewhere then I could try to write a PcW16 specific version of the program with more accurate time measurement. However it could take a time, I need to find and read the documentation and to write the code.
It has an advanced CPU (look at the PCB), IIRC it's some kind of custom Z80 (I hope not to mix things up though). The Z280 was buggy (a little bit) and the Z380 was different again.
I prefer the Z80 itself, because it provides all opcodes. The Z180 f.e. does miss some of the important non-documented (8 bit parts of IX and IY f.e.).
If the PcW16 would have a color screen, it would have been very successful. It's OS is really great, better than apple imho.
Does anybody know something specific about the z280's bugs? Are there a list of them somewhere?
Indeed the Z180 and Z380 missed several useful, albeit undocumented instructions but they had a lot of new instructions and ability to work with large amount of memory without paging. The Z380 could be much faster than the Z80.
IMHO it would have been interesting if PcW16 had used the ARM and software emulation for the Z80. The ARM at 16 MHz could beat 80486 at the same frequency. It could be at least 4-6 faster than the Z80.
I have one, too.
Its Z80 is not a discrete device, it is incorporated into one of the custom chips (the ASIC?). In use it is pretty sluggish and the "cabinet" (a flash memory used to store files) is small. The floppy drive is 1.44 MB but seems to have been intended as a backup drive only. There is a CP/M Plus implementation for it (John Elliot wrote it) which is nice, but it runs as an emulation under the PCW16's OS and has to do lots of page switching to work at all (according to JE). So as a result it isn't much faster (subjectively) than a PCW. Impressive achievement, though.
It is a bit odd that there is no direct way to run CP/M on the Z80-based system. I can't even imagine what prevents just to boot CP/M.
IMHO 1 MB of flash was too small, it should have been at least 4 MB.
