🚀 go-pugleaf

"Warren H. Minix" <minix@che.udel.edu> wrote:
>
>Ed,
>	The original statement was correct.  The 8088 was the cheapo 
>chip, which was why the XT's and AT's followed so quickly.  
>


Not quite.  The XT used an 8088 as well, but with a hard disk.
The AT went to the 80286.  The only IBM computers to use the 8086
were the low-end model 30 PS/2 systems.                        ^^


>
>
>> I think I smell something here...  The 8088 was a 16-bit machine and the
>> 8086 was the 8-bit machine that IBM wanted instead.  The 386SX is better
>> Get off the drugs.
>> Edward

8088 = 16 bit, 8 bit external data bus, 20 bit address w/ segmentation.

Used in PC because of the availablity of 8 bit devices, as well as the 
fact the 68000 was "too powerful" to ever be used for a personal computer.

8086 = 16 bit, 16 bit  "      "  " 

80186/80188 = 16 bit, same as corresponding 8088/86 except slightly faster
and a few extra instructions--usually listed as added in the 80286.  It
also has some integrated circuitry that simplified system design, but it
was mapped to Different Addresses than IBM had done, so not very compatable,
hence the lack of use in PCs.

80286 = 16 bit, 24 bit address space in protected mode.  Few extra instruct-
ions, including proteced mode and 80186 codes.  Used in AT.  ISA bus created
as extension to 8 bit bus for 80286.

80386(DX) = 32 bit, 32 bit data, 32 bit address in protected mode.  Can emulate
a 80286 protected mode, or many 8086/88 virtual machines.  Provides memory 
remapping, pageing, protection, etc.  Hardware capable of running true multi-
user multitasking operating systems.

80386 SX = 80386 DX with 16 bit external data bus.  Not all address lines taken
to external pins.

80486 (DX) = Faster (pipelined) 80386, with FPU on chip and on-board cache.
Note that the cache is basically the reason the 80486 out-performs an
80386 computer.

80486 SX = 80486 w/o the FPU.  Basically a 80386 w/ cache.

Pentium = Faster 80486.  64 bit external data bus, although 32 bit internally.
Uses optimization techniques and additional pipelines over 80486.  Very
cache dependant: will run slower than a 80386 if cache is disabled, since
each instruction takes more clocks, and can only work on more than one instru-
ction if the cache is full.  

80486 DX/2 and SX/2 = clock doubled internally.  External bus runs at half the
processor speed.  

80486 DX/4 = clock trippled cpu w/larger cache.  (Note DX4/100 can be run
in x2 mode, ie 50 MHz external, although most motherboard circuitry designed
for 33 MHz, hence the trippling.)

486DLC, 486SLC, etc. TI, CYRIX, AMD, IBM.  Many companies market 486 clones.
Low power, w/o FPU, and other features exist.  Typically use smaller cache
to save costs.

M1, K5, Nx586: Pentium-class processors that can outperform a pentium.

P6: Intel's newest processor, is heavily pipelined, out-of-order execution,
etc.  Optimized for 32-bit only code.  16 bit code and data can cause the
processor to 'stall'; this makes it slower than a Pentium.  Only performance
gains on 32 bit Operaing system and applications.  (unix variant, OS/2, 
Windoze NT, etc)  NOT: Windows 3.1x, '95, DOS, OS/2 1.x

I hope I am correct with this info.  It is from memory.

Kevin
vanmaren@fast.cs.utah.edu