DUV11 Line Interface
The DUV11 Line Interface is a synchronous serial line interface for the QBUS. It used programmed I/O (with separate receive and transmit interrupts) to transfer data; it was double-buffered for both input and output.
The character length (5, 6, 7 or 8 bits), and the sync character, were selectable; parity (even or odd) was optionally supported for error detection. It could also be set to discard additional incoming sync characters; it could operate in either half-duplex or full-duplex mode. All configuration, as well as all the modem control leads, could be set under program control. A switch allows configuration of whether one or two contiguous sync characters is needed for synchronization.
It was a quad-width card, the M7591; a Berg header on the card provided the 'native' EIA interface. For operation without a modem, an external clock could be used; a switch-selectable option also allowed the use of an internal clock.
|Receiver Status Register||RxCSR||16xx10|
|Receiver Data Buffer Register (read only)||RxDBUF||16xx12|
|Parameter Control Register (write only)||PARCSR||16xx12|
|Transmitter Status Register||TxCSR||16xx14|
|Transmitter Data Buffer Register||TxDBUF||16xx16|
The address should be allocated from the floating device address space; it is factory-configured to 0160010. It uses a single interrupt vector (for 'done'), which should be allocated from the floating device vectors; it is factory-configured to 0440.