My flash programmer/bus controller PC app and Arduino app now talk to the GPIO/SPI CPLD.
Here is how I set the baud rate on the MAX3110E UART now:
I also finished the Intel Hex flash programmer. It’s not fast, but it works. It will do until I can have flash programming built into the Z-80 code.
So, I decided that I should come up with a way to ensure the CPU is working with something simple. So I decided to try this: which will just spam ‘A’ out the serial port (I think–need to make sure I have enough NOPs and make sure it really does what I think it does).
This is spam.s:
It’s assembled with this:
where -o causes the .rel to be generated and -i causes the linker to produce a .ihx file.
which produces spam.ihx:
Those strings of zeroes are the ‘nop’ opcodes, so it looks reasonable. I have already used the new Intel Hex feature of the flash programmer to program it to the flash. So once the Z-80 is plugged in, it should immediately start spamming ‘A’ to the serial port.
So, now I’m getting ready to make the connections I need to insert the 2MHz oscillator, RAM, and Z80. I need to:
rewire RESET to the button
BUSACK to the flash programming system
BUSREQ to the flash programming system and pulled high