From: utzoo!decvax!harpo!seismo!hao!hplabs!hpda!fortune!guzis
Newsgroups: net.micro.68k
Title: Re: 68k vs. 8086 - (nf)
Article-I.D.: fortune.793
Posted: Thu Feb 17 23:34:58 1983
Received: Sun Feb 20 04:14:40 1983
References: ucbcad.601 grkermit.295 npoiv.1969


The one thing the 80186 has really going for it is the simplicity of inter-
facing more than anything.  With 2 DMA channels and 4 timers and 6 programmable
chip selects onboard the chip, we'll doubtless see quite a few products using
it.  And yes, Intel has reworked some of the instructions, most notably the
multiply (35 clocks on the 186, vs. 70 on the 8086).

As far as the 286 is concerned, as of this date, nobody's even seen a fully
functional one.  The A-step samples out do not have the memory managment
working yet and there are some pretty strange things happening with interrupts.
And the darned thing won't run correctly with interrupts at 8 Mhz; you have
to decrease the clock speed to about 7.5 Mhz.  Intel's due to sample the
B-step parts later on this month.

By the way, the 80287 doesn't interface to the 80286 the same way that
the 80187/80186, 8087/8086 combinations do.  What with all that memory
management logic onboard the 286, the 287 can't know when the MMU registers
have been changed.  So the 287 operates on an I/O port.  This undoubtedly
will have some effect on the timings.