There's a few of these I think are related. I'm currently trying to get a GEM-10 to work. The few times it's fired up it's proclaimed it's a P-10 motherboard. I did some internet searching and found similar BIOS strings and searched for the Peter-10. The BIOS strings say:
P-10 BIOS V3.60
(C) ZETA Ltd. 1989
I've found some *REALLY* similar boards with similar BIOS strings.
Here's my GEM-10: http://ns4.reboot.net.au/hardware/pics/yum-cha/GEM-10/
If you zoom in on the ROM sticker it's a "P-10/F" label.
Here's the Peter-10: http://dosdays.co.uk/topics/images/zeta_xt.png (Scroll down).
Given mine has chips that have date codes of at lates 09th week of 1989 and a BIOS copywrite of 1989 .. and the Peter-10's are 1991 vintage I suspect I just have an earlier version.
Still trying to get board up and stable 😀
Regards,
Al.