MCD(4) BSD Kernel Interfaces Manual MCD(4)
mcd -- Mitsumi CD-ROM driver
The mcd driver provides a data and audio interface to the Mitsumi-brand CD-ROM player. The CD-ROM player must be interfaced to the ISA bus
through one of the Mitsumi proprietary controller boards. The controller boards supported are the LU002S, LU005S, the FX001 and the quite
The mcd driver responds to disk-specific ioctl() commands, namely the DIOCGDINFO, DIOCGPART, DIOCWDINFO, and DIOCSDINFO, commands. Other
disk-specific ioctl() commands will return an error.
The mcd driver also responds to special CD-ROM ioctl() commands. These commands control the CD-ROM player's audio features. The commands
CDIOCREADSUBCHANNEL get sub-channel information on current status of disc playing
CDIOCREADTOCHEADER get table of contents header
CDIOCREADTOCENTRYS gets all of the table of contents
CDIOCPLAYTRACKS begins audio playing at location specified
CDIOCPLAYBLOCKS fails with error EINVAL
CDIOCPLAYMSF begins audio playing at location specified
CDIOCRESUME resumes playing a previously paused disc
CDIOCPAUSE pauses a playing disc
CDIOCSTART begins playing a disc
CDIOCSTOP stops a previously playing disc
CDIOCEJECT opens the disc tray (there is no support for a corresponding un-eject command).
CDIOCRESET stops any play and resets the Mitsumi controller board
CDIOCSETDEBUG cause the kernel to print debug messages to the console about the mcd driver
CDIOCCLRDEBUG cause the kernel to quit printing debug messages about the mcd driver
The ioctl() commands defined above are the only ones that the mcd driver supports. There are other CD-ROM related ioctl() commands (such as
CDIOCSETVOL and CDIOCSETSTERIO) which are available and may be supported by future versions of the driver.
/dev/(r)mcd0a accesses BSD partition on the disc. Normally, there is only one file system on a CD-ROM disc.
/dev/(r)mcd0c accesses raw device.
The character-mode devices for the mcd driver should only be used for accessing the audio features of the CD-ROM player as the performance on
data is abysmal.
The current version of the driver uses neither the DMA or IRQ features of the interface board, although it has an interrupt handler for any
IRQ requests that are generated. Until the DMA features are supported, the only interrupts that the board generates are those that are not
supported by the driver anyway.
An mcd driver appeared in FreeBSD 1.0.
The driver was written by Holger Veit (data part) and Brian Moore (audio part). Changes were provided by Gary Clark II, Andrew A. Chernov,
and Jordan K. Hubbard.
December 8, 1994 BSD