[Info-vax] Webinar "AUTOGEN and SYSGEN"

[Bart Zorn]

I have not attended the webinar held on January 28 titled "AUTOGEN and SYSGEN : History and architecture.". I downloaded both the PDF and the WMV file as posted on openvms.org. I am not able to play the WMV file: VLC on both OS X and Windows cannot play it and Windows Media Player can play it but there are two voices speaking at the same time about different points of the presentation.

So I am not able to find out exactly what was said during the webinar.

Reading through the PDF I stumbled upon the following on slide 8:

SYSBOOT gets an implicit USE CURRENT
• Brings the current set into working memory
• SET commands change working memory
• CONTINUE command does an implicit WRITE CURRENT
• Once booted, the ACTIVE set is materialized from the CURRENT set

I think something is wrong here. The first two bullets are OK. But the third one is, IMHO, not true. SYSBOOT does not do a WRITE CURRENT. It is SYS$STARTUP:VMS$INITIAL-050_VMS.COM (called by SYS$SYSTEM:STARTUP.COM) which does or does not do a SYSGEN WRITE CURRENT, depending on the value of the WRITESYSPARAMS parameter.
The fourth bullet is also not correct. It should read something like "Once booted, the ACTIVE set is materialized from the working memory of SYSBOOT"

This can be easily verified by changing, in SYSBOOT, the value of some parameter and setting WRITESYSPARAMS to 0. Then issue the CONTINUE command and after VMS has started up, verify the value of that parameter with SYSGEN. The changed value of the parameter is NOT reflected in the CURRENT set. It IS reflected in the ACTIVE set, however. In other words, no WRITE CURRENT command (or equivalent action) has been executed, neither by SYSBOOT nor by VMS.

Note that WRITESYSPARAMS has a special treatment by SYSBOOT. Initially it is set to 0. As soon as you change any other parameter's value, SYSBOOT set WRITESYSPARAMS to 1, Therefore, if you want to inhibit the WRITE CURRENT during startup, you have to set WRITESYSPARAMS to 0 just before you enter the CONTINUE command.

The question remains: why did the presenter not verify his slide before the webinar?

Any comments from anybody who did attend the webinar?

Thanks,

Bart