CT (4) | Special files and drivers | Unix Manual Pages

In /boot/device.hints:

For most PC-9801-55, -92 and compatibles:
.Cd hint.ct.0.at= "isa"

For ELECOM bus-master SCSI adapters:
.Cd hint.ct.0.at= "isa"
.Cd hint.ct.0.flags= "0x30000"

For I-O DATA SC98 adapters:
.Cd hint.ct.0.at= "isa"
.Cd hint.ct.0.flags= "0x10000"

For LOGITEC adapters:
.Cd hint.ct.0.at= "isa"
.Cd hint.ct.0.flags= "0x50000"

For TEXA adapters:
.Cd hint.ct.0.at= "isa"
.Cd hint.ct.0.flags= "0x20000"

For adapters with SMIT transfer mode to enable SMIT transfer:
.Cd hint.ct.0.at= "isa"
.Cd hint.ct.0.flags= "0x40000"
.Cd hint.ct.0.maddr= "0xdc000"

Flags meaning:

0x00000	DMA transfer mode for an NEC PC-9801-55, -92 (or compatibles), ICM IF-2660, Midori-Denshi MDC-554NA, or Logitec LHA-N151
0x10000	DMA transfer mode for an I-O DATA SC-98II
0x20000	bus-master transfer mode for a TEXA HA-55BS2, its successors, or Midori-Denshi MDC-926R
0x30000	bus-master transfer mode for an ELECOM bus-master SCSI adapter
0x40000	SMIT transfer mode (for supported adapters only)
0x50000	bus-master transfer mode for a Logitec LHA-20x series, ICM IF-2766, IF-2766ET, IF-2767 or IF-2769