Create a serial port in the Vectrex address space #50
Description
A serial port connected to a terminal emulator on a PC is handy for debugging and allows interactive environments like Forth or BASIC to run.
I'd like a serial port to run something similar to my serial port handler that works on a VecFever (code below is in Forth):
HEX
\ VecFever UART serial port interface. VecFever provides buffering (256 bytes each way?)
7FFB EQU v4eTxStatReg \ Read, negative if transmit buffer is in use, positive otherwise
7FFB EQU v4eTxByteReg \ Write
7FFC EQU v4eRxStatReg \ Read, zero if no data received, otherwise != 0
7FFD EQU v4eRxByteReg \ Read, upon reading, 7FFC is automatically cleared
7FFE EQU v4eLEDReg \ LED Register, probably read/write?
CODE KEY? \ -- f return true if char waiting
6 # ( D) PSHS, CLRA, v4eRxStatReg LDB,
NE IF, -1 # LDB, THEN, NEXT ;C
CODE KEY \ -- c get char from serial port
6 # ( D) PSHS, BEGIN, v4eRxStatReg LDB, NE UNTIL,
v4eRxByteReg LDB, CLRA, NEXT ;C
CODE EMIT \ c -- output character to serial port
BEGIN, v4eTxStatReg LDA, MI UNTIL,
v4eTxByteReg STB, 6 # ( D) PULS, NEXT ;C
Describe alternatives you've considered
Other alternatives are available, but a VEXTREME is cheaper than the other alternatives and/or potentially provides a lot more functionally.