tc —
TURBOchannel expansion bus driver
The tc driver provides machine-independent support for
  the DEC TURBOchannel expansion bus found on all DEC 5000-series machines with
  MIPS, DEC 3000-series with Alpha processors and VAXstation 4000 machines with
  the optional TURBOchannel adaptor.
Your system may support additional TURBOchannel devices. Drivers
    for TURBOchannel devices not listed here are machine-dependent. Consult your
    system's intro(4) for
    additional information.
NetBSD includes machine-independent TURBOchannel
  drivers, sorted by device type and driver name:
  - asc
- PMAZ-A single-channel SCSI adapter
- tcds
- PMAZ-DS, PMAZ-FS, PMAZB-AA and PMAZC-AA dual-channel SCSI adapters
 
  - fta
- PMAF-F DEFTA FDDI controller
- le
- LANCE Ethernet interface
 
  - cfb
- PMAG-B CX colour unaccelerated 2-D framebuffer
- mfb
- PMAG-A MX monochrome framebuffer
- px
- PMAG-C PX accelerated graphics boards
- pxg
- PMAG-D, PMAG-E and PMAG-F PXG accelerated graphics boards
- sfb
- PMAGB-BA HX colour unaccelerated 2-D framebuffer
- tfb
- PMAG-J TX 24-bit colour unaccelerated 2-D framebuffer
 
  - ioasic
- baseboard IO control ASIC for DEC TURBOchannel systems
- tcu
- TC-USB USB host and GPIO option
 
asc(4),
  cfb(4),
  fta(4),
  intro(4),
  ioasic(4),
  le(4),
  mfb(4),
  px(4),
  pxg(4),
  sfb(4),
  tcds(4),
  tcu(4),
  tfb(4)
The tc driver first appeared in NetBSD
  1.1.
The tc driver makes poor use of interrupt priority on
  the 5000/1xx series systems.