This adds support for building the apple one design for icoBoard with attached Digilent Pmods for VGA, PS/2 or UART.
VGA port is working through a Digilent VGA Pmod on Pmod 1/2.
PS/2 works through a Digilent PS/2 Pmod on Pmod 3 upper row.
UART works through a Digilent USBUART Pmod on Pmod 4 upper row.
By default, UART is enabled (and PS/2 is off), check rtl/boards/icoboard/apple1_hx8k.v.
Install a recent IceStorm toolchain, and:
$ cd yosys
$ make apple1
To load BASIC type "E000R" with CAPS LOCK on.