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flohofwoe • last Wednesday at 5:33 PM • 1 reply • view on HN

The hardware could be controlled via memory mapped 16-bit registers, e.g. checking whether the left mouse button is down is a single instruction:

    btst #6, $bfe001
The OS used a simple assembly-friendly calling convention, parameters were passed in registers instead of the stack (and the API documentation mentioned which parameters are expected in which registers), and the reference manuals usually had both C and assembly examples, etc... basically lots of little things to make the lives of assembly coders easier.

This YouTube playlist gives a nice overview of assembly coding on the Amiga (mostly via direct hardware access though): https://www.youtube.com/playlist?list=PLc3ltHgmiidpK-s0eP5hT...

Replies

kragen • last Thursday at 1:05 PM

Also, using a 68000 instead of a shitty Intel processor was a huge boon to assembly programming. Ultimately Intel won in the market and eventually even shipped processors that weren't profoundly unpleasant at the assembly level, but the 68000 is still a much more pleasant architecture for the assembly programmer. ARM is nicer still, but this was before ARM's existence as a separate company from Acorn.