T — Atari ST/TT (m68k)

Planned realm

The T realm is not built yet — it’s the “or at least it will be” half of Atari-XT. This page records the direction; nothing here is implemented.

The “T” in Atari-XT is the Atari ST line, after the sT / tT machines. Where the X realm is a fabric reproduction of the 6502 Atari, the T realm targets the 680x0-family Atari — the ST, STe, and TT — so the same box can run GEM/TOS-era software.

The current plan hosts the m68k by emulation on the spare Cortex-A9 (a JIT translating m68k → ARM, reusing existing open-source ST emulation) rather than building a 680x0 soft core in fabric. Running a protected multitasking TOS variant (e.g. FreeMiNT) needs the MMU’s memory protection, which the A9 provides directly. The multitasking and executable-loading design across all three CPUs — ARM, 6502, and this m68k target — is sketched under Multitasking & executable loading.

Like the X realm, the T realm will share the underlying hardware: the display compositor, the xt-blitter, audio, DDR3, and the ARM PS — appearing as another scalable window on the 1080p desktop when running in emulation mode, or just using the desktop natively as a GEM surface when running flat-out at max speed.