Sinclair QL

The QL (“Quantum Leap”, 1984) was Sinclair’s attempt at the business market — a genuine step up in architecture from the Z80-based Spectrum line, built around Motorola’s 68008 and its own multitasking-capable QDOS operating system, bundled with a full office suite. It’s remembered as much for its rushed launch (early units shipped with unfinished ROMs and unreliable Microdrive tape-loop storage in place of a floppy drive) as for its architecture, but it found a following anyway — Linus Torvalds famously learned to program on one, before it indirectly nudged him toward the 386 PC on which he wrote the first Linux kernel.

Reference photo: Wikimedia Commons (“Sinclair QL Top.jpg” by Ewx / Richard Kettlewell / Ubcule), CC BY-SA 3.0.