[Info-vax] VAX vs. MV/8000 [was Re: Hard links on VMS ODS5 disks]

[Arne Vajhøj]

On 8/25/2023 10:36 PM, abrsvc wrote:
> On Friday, August 25, 2023 at 8:33:10 PM UTC-4, Arne Vajhøj wrote:
>> Both DEC and DG considered it important to be able to
>> run old 16 bit applications on their new 32 bit system.
>>
>> Both DEC and DG was willing to add support for the
>> 16 bit instructions in the hardware (as opposed to
>> DEC a little over a decade later when the 64 bit support
>> for 32 bit applications was software based: VEST).
>
> VEST was not intended to be a vehicle for 32 programs to be transformed into 64 bit.

No it was a software solution to the problem of running
application from old architecture on new architecture
solved via sofware instead of via hardware.

 > It was intended for VAX programs to run under Alpha without the need for
 > having source code access. Many customers were happy that this worked as
 > well as it did because of their lack of original source.  VESTed
 > programs still had access only to 3 bit space. There are sites today
 > still running VESTed images on Alpha systems.

I am sure a lot of early VMS customers were also happy with
compatibility mode. It solved a problem.

The solution back then was just different.

Arne