[Info-vax] RSTS/E and VMS connection

[Johnny Billquist]

On 2023-04-08 00:26, Arne Vajhøj wrote:
> On 4/7/2023 5:22 PM, Johnny Billquist wrote:
>> On 2023-04-07 01:02, bill wrote:
>>> WE have often heard that VMS on the VAX was the logical procession
>>> from RS11 on the PDP.  I was looking around at my bookshelf and saw
>>> my 1983-84 RSTS/E PDP-11 Operating System book and it kinda piqued
>>> my interest so I picked it up and did a  little lite reading.
>>
>> Well. Internally, VMS is like a scaled up RSX in many (most?) corners. 
>> Most data structures and designs were (are) more or less the same as 
>> in RSX, but scaled up for 32-bits and whatever logically came out from 
>> there. A lot of system calls is the same story. And initial release of 
>> VMS mostly used all RSX cusps, running in compatibility mode, and 
>> slowly getting replaced with native things. Early versions of VMS I 
>> seem to remember even might still have used ODS-1, or some hybrid 
>> between ODS-1 and -2. I clearly remember the 9+3 character filename 
>> limitation in my earliest memories of VMS.
> 
> Before my time (I started with 4.4) but I thought the 9+3 to
> 39+39 change happened with VMS 3.x -> 4.0 not with ODS-1 to ODS-2?

My earliest VMS was 3.6 or 3.7. Which seems to match very well with a 
memory that it changed with V4.

But was it ODS-2 already at VMS V3? I guess it might have been, but I 
thought the filename format, as well as directory structure hadn't 
changed in ODS-2. But if you are right, then the ODS-2 spec must have 
changed?

   Johnny