Sinclair QL, Motorola 68008 and Microdrive

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A friend of mine sent me one Sinclair QL in a big box with manuals and accessories (ROM modules, floppy controller, IDE controller, 512k RAM expansion, RS232 adapter) because I wanted to test it using our benchmark and compare the results with 8088 in PC and Motorola 68000 in Amiga 500.

Sinclair equipped the computer with Motorola 68008. The standard 68000 CPU has a 16-bit data bus, but this smaller version has it only eight bits wide. The rest is the same so there are 32-bit CPU registers and 16-bit ALU. Using the narrowed data bus was an understandable way to make computers cheaper. IBM PC 5150/5160 has also its data bus eight bits wide. On the other side Intel 8088, unlike Motorola 68008, has a small prefetch queue so there should be smaller performance loss in comparison with a standard version of the chip.

I’ve never done anything with Sinclair QL so this is my first time. I’m quite surprised that the keyboard is mechanically much better than the one on Sinclair Spectrum+ (which looks almost the same). Also two integrated Microdrive units are easy to use and surprisingly fast. Each tape can hold 100kB of data and having two drives allows for easy tape copy.