Dave
Yes, sorry, Im talking about ArcaOS. When booting he initial screen shows 2 processors activated, so SMP.
So I'll change COM.SYS to PSCOM.SYS.
I can't see an entry for USBCOM.SYS. There are entries for USBPRT.SYS and USBD.SYS. Don't know if these are relevant.
Paul