Sep 23


Finally an almost stable implementation of PSG audio chip SN76489 from TI and Cassette TAPE circuitry. This implementation of the PSG is not exactly the same as original, this one (named 'SN76490' by me...) doesn't slowdown the cpu including WAIT cycles, due to availability of a command FIFO inside the chip that speed up bus operations. The generated audio routes to the CODEC audio engine that drives the onboard Wolfson WM8731 chip as DAC and as ADC using the integrated LINE-IN. The tape signal is sampled, filtered and converted with a simulated Schmitt Trigger.

Last but not least, the PS2 keyboard connected to DE1 board, handles the SK1100 SEGA keyboard implementation, translating every keycode into SK1100 map.

The video shows every modules with a fully working tape loading stage.

Thanks to SC-3000 Survivors website and his founder Digimorf for the online tape programs and for incredible virtual SR-1000 TAPE loader!!!



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