12 Mar
2003
12 Mar
'03
10:37 p.m.
On Wed, 12 Mar 2003, Fred Cisin (XenoSoft) wrote:
Yep... We made use of them in the V40 that we used for many years in embedded
Stuff. Plus the V40 has (had?) a really nice DMA controller.
snip...
Peter Wallace
> > Not
that I know off. The V20 did behave exactly like an 8088.
> Besides, it wasn't a completely Bug-For-Bug replacement. NEC failed to
> implement some of the quirks of the 8088. For example, if an interrupt
> occurred during the execution of an instruction with a double prefix, the
> NEC would continue, but the intel would drop one of the prefixes when
> resuming.
> REP MOVSB DS:[SI] DS:[DI]
> will resume with a V20, but with an 8088 will only do one more rep after
> an interrupt.
On Wed, 12 Mar 2003, Hans Franke wrote:
Well, that's eactly the 186 behaviour. Now
considering that the
Not MY experience. The 386 is the first Intel that I'm aware of that
fixed the double prefix bug. But NONE of the NEC v series had that
bug. (ONE way to tell whether the current chip was Intel or NEC)
timeing was also exactly like 186 (or real mode
286), and the
instruction set is the same, I still think NEC just used the
Did the V20 have the INSB/INSW/OUTSB/OUTSW instructions? (present in
80186/80188, but not 8086/8088