[rescue] IBM on ebay

[James Lockwood]

On Mon, 13 May 2002 dave at cca.org wrote:

> mrbill at mrbill.net writes:
>
> >On Mon, May 13, 2002 at 12:10:27PM -0700, Fogg, James wrote:
> >> Wow, a risk-free way to get into an IBM mainframe environment. If I had 6K
> >> I'd do it.
>
> >Anybody know what the *smallest* S/390 is?  Is it one of those goes-in-an-AT
> >cards?
>
> Aside from the obvious performance issues, wasn't that AT/390 thingy
> actually not fully compatable?

There was no AT/390.  The AT/370 was a 2 ISA board mutant that implemented
most of the 370 instruction set in microcode on a modified mask 68000, and
emulated some of the rest with a vanilla 68000.  It didn't have full
support for priv instructions and only ran a single user version of
VM/CMS.

The smallest /390 is probably the P/390 or R/390, essentially one-card
PCI or microchannel implementations of the 390 arch.  They make
respectable development systems, I would have loved to have had one when I
was doing MVS application development.

-James