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Home Forums 68kMLA Mac SE/30 to SCSI chip pinouts — #16
Post #16 by trag
Source Forum68kMLA
Category68k
Post DateWed, 10 Oct 2012 - 23:33
Original URLhttps://68kmla.org/bb/threads/mac-se-30-to-scsi-chip-pinouts.26313/
Post
I guess these old processors aren't pipelined at all?

So a simple memory access takes a cycle to fetch the instruction (if it's in cache and not in RAM) and a cycle to decode, and a cycle to put the address on the address bus and a cycle to receive or write the data, or something like that? And maybe more than one cycle to fetch the instruction if it's a multi-word instruction, perhaps with a 32 bit address embedded in it?

Is that close to how it's working?

I'm so used to thinking of a memory access taking one cycle these days, that I've always considered the SE/30 as having a theoretical bandwidth of 32 bits X 16 MHz = 64 MB/s. So wrong. Sigh.

mp.ls