The imported T80 CPU and the upstream ULA raster ran a user-supplied 48K ROM at 3.5 MHz, printed BASIC, and ran a typed program. The Spectrum's 50 Hz frame is captured whole into a triple buffer and scan-converted to 720p60 without tearing.

A status UART on a PMOD pin now reports PLL lock, opcode fetches and memory writes, so a blank screen is no longer the only diagnostic. The same day the upper 32 KiB of the 48K machine moved into DDR3 and the ROM still printed the same loop, five loads out of five.

Episode 4: We Gave the Tang Console a 1982 ZX Spectrum ROM. It Booted.