4B - Z100 - Slave 8259 - S100 vectored line 3
 4B - Common Access Method SCSI interface (draft revision 1.9)
 4B - Acorn BBC Master 512 - "OSBYTE" - MISC FUNCTIONS USING REGISTER PARAMS
 4B80 - IBM SCSI interface
 4B8102DX0000 - Virtual DMA Specification (VDS) - GET VERSION
 4B8103 - Virtual DMA Specification - LOCK DMA REGION
 4B8104 - Virtual DMA Specification - UNLOCK DMA REGION
 4B8105 - Virtual DMA Specification - SCATTER/GATHER LOCK REGION
 4B8106 - Virtual DMA Specification - SCATTER/GATHER UNLOCK REGION
 4B8107 - Virtual DMA Specification - REQUEST DMA BUFFER
 4B8108 - Virtual DMA Specification - RELEASE DMA BUFFFER
 4B8109DX0000 - Virtual DMA Specification - COPY INTO DMA BUFFER
 4B810ADX0000 - Virtual DMA Specification - COPY OUT OF DMA BUFFER
 4B810B - Virtual DMA Specification - DISABLE DMA TRANSLATION
 4B810C - Virtual DMA Specification - ENABLE DMA TRANSLATION
 4B810D - QEMM-386 - BUG