Interface Circuits: Serial & Parallel - ENCAD NovaJet Pro 600e Service Manual

NovaJet PRO 600e Service Manual
Interface Circuits: Serial & Parallel
Data from the host computer is received either through the Centronics
parallel port or the serial port. The gate array provides the control
signals for DMA transfers from the parallel port to DRAM.
The serial port is designed primarily to interface to a Macintosh printer
port. It has an eight pin Mini-DIN connector. The data (TXD, RXD)
signals meet RS-422 electrical specifications, and the control signal
(DTRCLK) meets the RS-423 electrical specifications. The control
signal can be configured as a 1MHz clock for high speed serial commu-
nications with a Macintosh.
The serial port is compatible with RS-422 devices when an appropriate
adapter cable is used. This cable is available from ENCAD.
2-14 Theory of Operation
Figure 2-10. Interface Circuits.