4 ms·
"I can't get over how a possible 24-bit generation didn't quite materialize in the 1980s, and find the eZ80 evokes a kind of nostalgia for an alternate history"
by jerf 1y ago
"I can't get over how a possible 24-bit generation didn't quite materialize in the 1980s, and find the eZ80 evokes a kind of nostalgia for an alternate history"
Well... it depends on how you look at it.
While the marketers tried to cleanly delineate generations into 8- and 16- and 32-bit eras, the reality was always messier. What exactly the "bits" were that were being measureds was not consistent. The size of a machine word in the CPU was most common, and perhaps in some sense objectively the cleanest, but the number of bits of the memory bus started to sneak in at times (like the "64 bit" Atari Jaguar with the 32-bit CPU because one particular component was 64 bits wide). In reality the progress was always more incremental and there are some 24-bit things, like, the 286 can use 24 bits to access memory, and a lot of "32 bit graphics" is really 24 bits because 8 bits for RGB gets you to 24 bits. The lack of a "24-bit generation" is arguably more about the marketing rhetoric than the lack of things that were indeed based around 24 bits in some way.
Even today our "64-bit CPUs" are a lot messier than meets the eye. As far as I know, they can't actually address 64 bits of RAM, there are some reserved higher bits, and depending on which extensions you have, modern CPUs may be able to chew on up to 512 bits at a time with a single instruction, and I could well believe someone snuck something that can chew on 1024 bits without me noticing.
- GianFabien 1y agoIn the world of mainframes and minicomputers there were several 36bit machines. They were chosen because you could pack 6x6bit char codes into one word. Yes, back then ASCII was entirely just the uppercase subset. Off hand I can't recall exactly how EBCDIC and 80 col card codes were mapped.