CPUblit is a hack/patch for the Amiga computer to perform some functions ordinarily handled by the blitter in Fat Agnus by using the CPU instead. It requires a 68020/030/040/060-based Amiga. It will run on a 68000/010-powered Amiga (The 68010 is a drop-in replacement for a 68000 and speeds up some operations) but will not provide any noticable speed improvement. It speeds up text scrolling dramatically on systems with a 68030 or better CPU, such as the Amiga 2500 and 3000.
CPUblit was quite intelligently designed. It is smart enough to only blit with the CPU when there are no tasks waiting, and it only handles blits which it can actually accelerate. It uses four different routines to perform the actual blit, depending on what kind of data is being copied. The blit routine is written in optimized 68k assembly code.
CPUblit 1.0 was released in April of 1991 by Eddy Carroll. The "license", such as it is, is undefined:
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* CPUBLIT.C
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* (C) Copyright Eddy Carroll, 1991. Freely distributable.
Nevertheless, full source is provided.
You can find CPUblit 1.0 as "CpuBlit.lha" in any Aminet mirror.