I have two friends that have PC-88's, one is
an MX version. Both of these machines, even
though they were bought 2 years apart have the same OS version, 1.01.

Is there a newer OS version for the PC-88? In
particular, the PC-88 MX has been experiencing some pretty weird behaviour (random resets, etc.) that I'm hoping an OS
revision would cure.

I'm assuming it's a ROM chip, is it field replaceable, or does it require shop time?

Thanks for any advice.

Jay Storey