NAME

mti − Systech MTI-800/1600 multi-terminal interface

SYNOPSIS

device mti0 at mb0 csr 0x620 flags 0xffff priority 4

DESCRIPTION

The Systech MTI card provides 8 (MTI-800) or 16 (MTI-1600) serial communication lines with modem control.  Each line behaves as described in tty(4). Input and output for each line may independently be set to run at any of 16 speeds; see tty(4) for the encoding.

Bit i of flags may be specified to say that a line is not properly connected, and that the line i should be treated as hard-wired with carrier always present.  Thus specifying “flags 0x0004” in the specification of mti0 would cause line tty02 to be treated in this way. 

To allow a single tty line to be connected to a modem and used for both incoming and outgoing calls, a special feature, controlled by the minor device number, has been added.  Minor device numbers in the range 0 − 127 correspond directly to the normal tty lines and are named tty∗.  Minor device numbers in the range 128 − 256 correspond to the same physical lines as those above (i.e. the same line as the minor device number minus 128) and are (conventionally) named cua∗.  The cua lines are special in that they can be opened even when there is no carrier on the line.  Once a cua line is opened, the corresponding tty line can not be opened until the cua line is closed.  Also, if the tty line has been opened successfully (usually only when carrier is recognized on the modem) the corresponding cua line can not be opened.  This allows a modem to be attached to /dev/tty00 (usually renamed to /dev/ttyd0) and used for dialin (by enabling the line for login in /etc/ttys) and also used for dialout (by tip(1C) or uucp(1C)) as /dev/cua0 when no one is logged in on the line.  Note that the bit in the flags word in the config file (see above) must be zero for this line. 

WIRING

The Systech requires the CTS modem control signal to operate.  If the device does not supply CTS then RTS should be jumpered to CTS at the distribution panel (short pins 4 to 5).  Also, the CD (carrier detect) line does not work properly.  When connecting a modem, the modem’s CD line should be wired to DSR, which the software will treat as carrier detect. 

FILES

/dev/tty0[0-9a-f]hardwired tty lines
/dev/ttyd[0-9a-f]dialin tty lines
/dev/cua[0-9a-f]dialout tty lines

SEE ALSO

tty(4), zs(4S)
The MTI-800A/1600A Multiple Terminal Interface User’s Manual, Rev. D, which comes with the multiplexer. 

DIAGNOSTICS

Most of these diagnostics “should never happen” and their occurrence usually indicates problems elsewhere in the system. 

mti%d,%d: silo overflow. More than 512 characters have been received by the mti hardware without being read by the software.  Extremely unlikely to occur. 

mti%d: error %x. The mti returned the indicated error code.  See the mti manual. 

mti%d: DMA output error. The mti encountered an error while trying to do DMA output. 

mti%d: impossible response %x. The mti returned of flags may be specified to say that a line is not From marty@ufo Sat Feb 25 16:04:52 1984

Sun Release 1.1  —  Last change: 6 April 1984