Author: Tom Kerrigan
Date: 12:54:34 07/03/03
Go up one level in this thread
On July 03, 2003 at 09:35:41, Robert Hyatt wrote: >>>>What x86 problems? The x86 has variable length instructions anyway, so you can't >>>>say that n-bit-long instructions limit it somehow. >>> >>>Sure I can. It first limits the number of registers to 3 bits. I'd bet >>>that if Intel could "start over" the ISA would be greatly different with a >>>target of 32 bits from the beginning. Intel grew up from 8 bits. Other >>>vendors started at 32 and their instruction sets are _far_ better. Motorolla >>>is an example with the 680x0. The sparc has a nice instruction set, it's just >>>a dog for performance. >> >>I don't know what in the world you're talking about. Grew up from 8 bits? Target >>32 bits? Started at 32 bits? Do you know what "variable length instructions" >>means? x86/680x0 didn't start at, target, or grow up from ANY length. > >Sorry, but the X86 _started_ as an 8-bit cpu capable of doing 16 bit math. >It grew to 16 bits in the 80286 and 32 bits in the 80386. But it was >originally an 8 bit ISA. Wrong, the 8086 (the first x86) is a 16-bit processor. The 8088 used in the original PC was a variant of the 8086 with an 8-bit data bus, maybe that's why you're confused. But now you're confusing instruction length with datapath width. Check the top of this post. We were talking about instruction width. Somehow you changed it to datapath width. -Tom
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.