#x86

Not to be confused with x86-32 and x86-64, x32 is a Linux-specific ABI designed to combine the computational efficiency of x86-64 with the memory efficiency of x86-32.

x32 uses the x86-64 instruction set, allowing for more registers and faster instructions, while using 32-bit pointers and 32-bit integers, allowing for a smaller memory footprint.

Smaller memory footprint also means that the CPU cache is more effective and less memory bandwidth is required.

Various benchmarks I've seen 'round the 'net show that x32 provides up to 40% less memory consumption and 10% faster performance (especially for pointer-heavy applications like Java) compared to x86-64

However, x32 has a couple disadvantages:

Applications are limited to up to 3GiB of virtual memory space each, like x86-32.

Most applications that have assembly optimizations wont work, or at least those parts wouldn't be optimized, unless the developers specifically add x32 support.

It is quite esoteric, and therefore more prone to bugs, due to the lack of users for testing.

There's a chance it'll be removed in the kernel some time in the near future. (There were talks of removing it back in 2018, but it didn't go anywhere)

No branches

No jumps

No calls (except to the function itself)

No mov instructions where the source is a location in memory

No indirection not of the form [rdi] + disp64

No mutating rdi

And check it out, it works!

If you want the explanation, I've exported my literate source code to HTML and screenshotted it below the cut. If you just want the source code, go here.

SINCLAIR PC200 (aka Amstrad PC20) 1988

The Sinclair PC200, released under the Amstrad brand, marked a significant shift from earlier Sinclair products. Essentially, it was Amstrad’s effort to attract the same market the Sinclair QL once aimed for: serious users and small businesses operating on a limited budget.

Technically, the PC200 was a heavily stripped-down IBM-compatible PC, featuring an Intel 8086 processor, CGA graphics, 512KB of RAM (expandable to 640KB), and no hard drive. It shipped with MS-DOS 3.3 and the GEM desktop environment from Digital Research. Optionally, an Intel 8087 math co-processor could be installed.

Although the machine offered two expansion slots, the case design made internal upgrades awkward — the top cover had to be removed permanently to access the slots, severely restricting expandability.

In reality, there was nothing unique about the PC200. It was a rebranded version of the PC20, previously launched by Amstrad in the US. Even the monitors were rebadged: the S14-CM (color) and S12-MM (monochrome) were essentially variants of the PC1640 and Schneider MM12, respectively. The only peripherals specifically released for the PC200 were a basic black Amstrad mouse and the SPJ-1 analog joystick.