R32V2020 ANSI Terminal with UART Interface
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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
