tepples wrote:
67.1 megabits, which is 64 mebibits or 64 of what the game industry called "megabits" in the mask ROM era.
That mask ROM era hasn't ended yet. As far as I know it's still absolutely common to use terms like "gigabit" or "gigabyte" for things like modern FLASH chips and SD cards, with "giga" meaning 1024^3, one reason is that chip manufacturing does somewhat require having a power of 2 for storage array. Whereas, SD cards are usually having an area reserved for automatic replacement of worn out sectors, so the available user space may appear to be less than expected, but that's unrelated to the 1000 vs 1024 thing.
Magnetic discs don't have that requirement for powers of 2, so manufacturers may often mean (1000^n) when they are saying "kilo/mega/giga" in their specifications (and for transfer rates and clock rates it's even more common to use 1000^n). Of course it would be neat to avoid that confusion, only, those new scientific units like "mebibits" are sounding a lot too much like childish language to me : /
As for myself, I would rather avoid to adopt those terms. Another approach would be defining the exact value in Hz or bytes somewhere in the introduction/specs, and then using an abbreviated value in the rest of the document; like 1234567Hz (1.2MHz), or 400h bytes (1Kbyte).
magno wrote:
Hope this handmade timing diagram will help to explain why I don't think CPU_RD is 3 master cycles in FastROM mode:
I've no idea which timings are correct... but your handmade diagrams & schematics are really pretty : )