[Info-vax] OpenVMS.Org quick pool

[Johnny Billquist]

On 2012-08-22 23:16, Bill Gunshannon wrote:
> In article <k13ci1$a5l$5 at dont-email.me>,
> 	David Froble <davef at tsoft-inc.com> writes:
>> Paul Sture wrote:
>>> On Wed, 22 Aug 2012 15:33:22 +0100, Single Stage to Orbit wrote:
>>>
>>>> On Tue, 2012-08-21 at 15:10 -0400, Stephen Hoffman wrote:
>>>>>> 32 bit is limited to a maximum of 4GB. One won't be able to do a lot
>>>>>> with that with today's software requirements.
>>>>> TKB
>>>> WTF is TKB?
>>>
>>> The RSX Task Builder, which was the equivalent of the LINK command on
>>> RT-11 and VMS.
>>>
>>> On both RT-11 and VMS, LINK was usually quite swift.  TKB was like
>>> watching paint dry in comparison.
>>>
>>
>> Well at least you could walk away from it.
>>
>> What was truly torture was the overlay definitions.
>
> Can't speak for RSX and TKB but I've done (and actually still do once
> in a while) overlays in Ultrix-11 and never found it all that difficult.
> Needed to get good at it just to make usable kernels. :-)

The problem with TKB is that it's like a swiss army knife.
(The slow taskbuilder was/is normally referred to as STK, by the way.)
I don't know how overlays in RT-11 work (I looked at it maybe 30 years 
ago, and never since, but I think it's similar to Unix). Overlays in 
Unix are really simple.
However, you cannot do some of the weird stuff that TKB allows you. For 
a simple type of overlays like in Unix, the TKB "syntax" is complex and 
weird, but that comes from being able to do all those other things that 
Unix can't, like co-trees, memory resident overlays, having your own 
overlay loading code, memory resident shared libraries thrown into the 
pot, supervisor mode stuff, I/D space, shared readonly segments between 
multiple copies of the program running, and god knows what else.
The Unix linker is so simplistic by comparison, that it's not even fair 
to mention them in the same post.

And yes, TKB can be hair rising to work with. It is also used to build 
shared libraries, for example. And there are various hooks for 
supporting some high level language needs, as well as debuggers, pretty 
advanced relocation address expressions... The list just goes on forever...

(Speed finally did become somewhat acceptable in the latest released, as 
an alternative version of TKB, linked as split I/D space itself, using 
supervisor mode libraries, and using memory resident overlays, which 
were flattened out, made it much faster, while still retaining all 
functionality.)

	Johnny