Very initial RS232 write support
Invert RS232 regs and controller
More RS232 work, icons
Add RS232 reg tests
Update RS232 icon
Fix format bug
Add RX-80 font for printer
Get printer to render characters better; add testing shell
Printer improvements & fix TB bug!

-- add PIO support
-- make TB compare the value of the bit, not its inverse
-- use SWT APIs for printing, not AWT, to improve speed
Fixup RS232 support after TB fix
Improve condensed/expanded spacing