So those pesky Intel chips put the least significant byte first, and your super efficient 680×0 code needs to translate? Easy! Rotate, swap, rotate. This takes advantage that the 680×0 32-bit registers can be operated on as if they are 16-bit, at least with certain…

Quick little thing related to the previous post. Unless otherwise disabled, the ZX Spectrum hardware issues an interrupt at the start of the processing of each TV frame (actually the “retrace” if I recall). This means to get “in sync” with the screen simply issue…

Z80 has a nice (for programmers) instruction to copy a block of memory (and similar types of operations), and it’s easy to remember how to use the magic that is LDIR, which stands for load, increment, repeat. Think of BC standing for byte count, DE…