F000:FFFEh System Model ID
Length: 1 byte
This byte specifies the machine type.
──────────────────────────────────────────────────────────────────────────
Use INT 15h, Service C0h, for a more accurate test of the system model
ID and the sub-model ID.
ID Machine Type
FFh Original PC
FEh Later PC, XT, or Portable PC
FBh Later XT
FDh PCjr
FCh AT or XT-286
F9h PC Convertible
Note that a few machines share IDs. To differentiate the machines, use
INT 15h, Service C0h, and look at the sub-model ID.