R32V2020 ANSI Terminal with UART Interface
Jump to navigation
Jump to search
Description
The ANSI terminal is an FPGA implementation of an ANSI display. The original design was created for Grant Searle's Multicomp project.
The terminal implements a subset of ANSI Escape codes.
The display has hardware cursor support and displays 80 characters per row times 25 rows of characters.
The R32V2020 implementation removes the PS/2 keyboard which had UK-101 key mappings.
Interface
The interface to the ANSI terminal is a 6850 ACIA (UART) interface. This interface consists of two memory mapped 8-bit ports - one status/control port and the data port.
Performance
- Measured the performance of the ANSI terminal using the R32V2020 CPU
- Char Write Speed = 0.78 uS/char or 1.2M chars/sec
- Screen Clear Speed = 100.2 uS
- Screen Scroll Speed = 3.94 uS
- Performance is much faster than the 60 Hz frame refresh rate
- Might make sense to add polling for Vertical Sync or possibly double-buffering
