Re: PC Transporter fun

[dempson@actrix.gen.nz (David Empson)]

Paul Schlyter <pausch@saaf.se> wrote:

> In article <1et0i2m.owt7vk1gsm9wN%dempson@actrix.gen.nz>,
> David Empson <dempson@actrix.gen.nz> wrote:
>  
> > Don't forget that the PC Transporter uses an NEC V30 processor, which
> > has additional instructions that are also available in the 80186
>  
> Already the NEC V20 had all the extra 80186 instructions.

I would have expected that the V20 and V30 were released at about the
same time, since they are the same architecture internally but with a
different data bus width (V20 is 8 bit, like the 8088 or 80188; V30 is
16 bit, like the 8086 and 80186).

In fact, the 8088 was released _after_ the 8086, but I don't know which
way around the V20 and V30 were released.

> > (and later family members).
>  
> This was a fuzzy claim.  Which later family members?  Only the 286?
> Or all of them right through the Pentium III ?

I meant that the extra instructions of the V20/V30/80188/80186 are also
available in the 80286, 80386, 80486, Pentium, etc., up to and including
the latest members of the family (as opposed to being unique to the
V20/V30/80188/80186).

> The V20 also had a nateive 8080 mode, which enabled you to run CP/M
> must faster than by emukating the 8080.  As a result, my 4.77 MHz V20
> PC ran CP/M programs some 2-3 times faster than my 16 MHz 386.

It is a pity that its 8080 mode didn't also support Z80 instructions.
In my CP/M development days, the Z80 was much more comfortable to use.
I briefly dealt with an 8085, which I found rather clumsy to deal with,
since I was used to the greater flexibility of the Z80.