PORTIBM PC Portable (uses same BIOS as XT) 0390-039F - Cluster adapter (ATIBM PC AT) 0390 ?? (adapter 0) (XTIBM PC XT) 0391 ?? (adapter 0) (XTIBM PC XT) 0392 ?? (adapter 0) (XTIBM PC XT) 0393 ?? (adapter 0) (XTIBM PC XT)