Eric Smith spacewar at
Wed May 1 16:47:36 CDT 2019

On Wed, May 1, 2019 at 1:54 PM Antonio Carlini via cctalk <
cctalk at> wrote:

> Then (I think) came the VAX 8600 and that needed VMS V4.0. That (I
> think, but I can't find anything to support this right now ...) is when
> the last of the PDP-11 compatibility code was finally removed.

The VAX 8600 and 8650 were the last VAX models to have PDP-11 compatibility
mode, so if the purpose of VMS 4.0 was to support the 8600, I would expect
it to still contain compatibility mode support. VMS versions at least as
late as 5.2 still supported the 8600. I don't have firsthand experience, as
the only 8600 I used ran BSD.

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