ZX-Badaloc Reloaded
Implementing the ZX-Badaloc Clone into an FPGA
The same board used as Tape and sd-card adapter is now populated with two 74HC166 shift registers, for joystick interface.
The 16 inputs can be read on Kempston I/O address ($1F). A bit (D7 on $1F) will select between upper or lower byte. If one 74HC166 is installed, it will be readable by default. In the future it will be possible to map any input to any key (as on the zx-badaloc clone).
This is the schematic of the joystick adapter.
Unfortunately there are not enough I/O lines on the two side connectors, so a short wire is necessary from J4 6-pin header.