Raster (Laser) Plotters
ROM: Read Only Memory
Read Only Memory (ROM) is a permanent form of memory that is written to during manufacture. The CPU can read information from a ROM location, but cannot write information into it. ROM information is non-volatile in that it does not change when power is removed.
RTC: Real-Time Clock
The real-time clock (RTC) mechanism is similar to the RTI although with some software it can easily be used to keep time in hours, minutes, days, etc.
RTI: Real-Time Interrupt
The real-time interrupt (RTI) mechanism is useful for generating a periodic interrupt automatically every x (programmable) amount of time. This can be useful for executing diagnostics, maintenance routines, and polling i/o or events.