[Info-vax] What are the earliest DEC operating systems you worked with ?

[Paul Hardy]

Jeffrey H. Coffield <jeffrey at digitalsynergyinc.com> wrote:
> 
> 
> On 03/04/2021 10:28 AM, Arne Vajhøj wrote:
>> On 3/4/2021 12:20 PM, Chris Townley wrote:
>>> On 04/03/2021 16:50, Marc Van Dyck wrote:
>>>> Simon Clubley laid this down on his screen :
>>>>> What are the earliest DEC operating systems you worked with ?
>> 
>>>> University, 1980. VAX/VMS V2.0 on a VAX 780.
>>>> 2,5 GB of memory, 3 disks of 72 MB each, a tape drive, and 40 serial
>>>> lines hooked to VT100 or LA120 (for APL, we were FT site) terminals.
>>>> Ah yes, and two LPxxx printers and a card reader.
>>>> Never left VMS after that, till now...
>> 
>>> That was a vast amount of memory then!
>>> 
>>> We ran a full production setup with 80 odd users in 1990 with 32Mb
>> 
>> I strongly suspect that it was a typo.
>> 
>> I don't think you could stuff 2.5 GB in a 780 and at 1980 RAM prices
>> it would be crazy expensive.
>> 
>> Arne
>> 
> Vax 11/780 max memory was 64MB.
> 
> Jeff
> 

The default for a 780 when launched was 1/4 MB (256K). When we got ours in
1979 I argued and got a further 1/2 MB to make 3/4 MB. It cost about a
quarter of the company profit for the year! The boss said that as we were
moving from a PDP-11 with 64KB, then 256 KB ought to be plenty!

Remember the V in VMS is virtual, and VMS pages were only 1/2 KB, so if you
had 1 MB you had 2048 pages to act as a memory window to the disk-based
page and swap areas.

-- 
Paul at the paulhardy.net domain