ZX Spectrum Next - Digilent Nexys A7-100T Port

Port of the ZX Spectrum Next core to the Digilent Nexys A7-100T board.

(may work on Nexys A7-50T)

Audio

Stereo audio output using PMOD_I2S2 (on PMOD Connection JB). IP can be reconfigured to use the onboard mono audio jack.

Tape

Tape input via PMOD_I2S2 (on PMOD Connection JB), Tape output via onboard mono audio jack.

Joystick

Joystick 1 emulation via onboard buttons (BTNU, BTND, BTNL, BTNR, BTNC).

Optional Joystick 2 via PMOD_JSTK2 (JXADC Connection bottom row).

Mouse

Optional Mouse via PMOD_PS2 (on connection JXADC top row)

RTC

Optional RTC support via PMOD_RTCC (on connection JD). If PMOD_RTCC not present, RTC is emulated (but with time and RAM reset on power reset).

ESP32

Optional wifi via PMOD_ESP32 (on connection JC)

Second SDCard Slot

Optional second SDCard via PMOD_SD or PMOD_MicroSD (on PMOD Connection JA)

LED Segment Display & RGB

LED Segment Displays clock speed, and memory address, and briefly video timings\settings during boot and video setting changes. RGB Leds display startup process and CPU wait states.

RGB can be disabled by writing 0 to PI Accel GPIO Pin 12 (enabled by writing 1)

LED Segment can be disabled by writing 0 to PI Accel GPIO Pin 13 (enabled by writing 1)

PI Accelerator

Use of the PI Accel GPIO to access on-board UART, Mic (via I2S), Switches and LEDS (via GPIO pins 2-11, 22-27)

Acknowledgements

ZX Spectrum Next source

Link: https://gitlab.com/SpectrumNext/ZX_Spectrum_Next_FPGA License: GNU GPL 3.0

ZXNext_MISTer Source and inspiration

Link: https://github.com/MiSTer-devel/ZXNext_MISTer License: GNU GPL 2.0

PS2 code from Digilent Vivado Library

Link: https://github.com/Digilent/vivado-library/tree/master/ip/axi_ps2_1.0 License: MIT License

I2S Transceiver code from Digikey

Link: https://forum.digikey.com/t/i2s-transceiver-vhdl/12845

SPI Code from nandland

Link: https://github.com/nandland/spi-master License: MIT License