/SMP /APIC is not supported - /APIC requires the /!NOD switch or the system will hang during boot due to IRQ conflict with USB controllers

Explanation of config.sys line PSD=ACPI.PSD /SMP /CD /TMR /APIC /!NOD
 /CD is required to enable USB drive access successfully
 /TMR is required shown by testing using TMRTEST.EXE
 /!NOD is required or boot stops at USBEHCD.SYS - removing that driver causes boot to stop at USBD.SYS; ie the problem is an IRQ conflict when High IRQs are enabled
