RE: Laymans explaination for single level store?

I'm not an expert, but none of the things you mention seem to be limitations
of SLS itself, rather limitations of the implementation of the OS.

In other words, you could develop an OS without the limits you mentioned
that used SLS.

The problem is IBM, chose not to do it 30+ years ago and for capabilities
sake hasn't changed.

Charles Wilt
iSeries Systems Administrator / Developer
Mitsubishi Electric Automotive America
ph: 513-573-4343
fax: 513-398-1121
 

> -----Original Message-----
> From: Steve Richter [mailto:stephenrichter@xxxxxxxxx]
> Sent: Tuesday, November 30, 2004 9:39 AM
> To: Midrange Systems Technical Discussion
> Subject: Re: Laymans explaination for single level store?
> 
> 
> just to keep things in perspective, the SLS does have its
> disadvantages.  It is after all 30 years old!
> 
> The 16 meg space size limit is a problem.  Why should the APIs that
> list to a user space have to include logic that cuts off the list
> because of the size limit of a space?
> 
> The object name limitation of 10 or 30 characters should not be.  Long
> symbolic names are very useful, esp for end users.
> 
> The use of 16 byte pointers to address any object or byte on the
> system is very elegant yes, but what is the "point"?  Pointers to
> system objects and pointers to data bytes are entirely different
> animals.  Why force them to share the same 16 byte structure? 
> Arguably pointers to system objects like programs and files should
> always be stored as symbolic links, with long object names and the
> ability to make that link a relative one ( search the library list )
> or an absolute link. A 16 byte system pointer has no place in a user
> application.  And my guess is that such pointers are a hassle in
> system code also, what with their built in permanent authority to the
> object pointed to.
> 
> The aspect of the system that has stood the test of time, the ability
> of a program to be automatically reassembled when the CPU instruction
> set has changed, has nothing to do with SLS.
> 
> The ability of the system to run code from 25 years ago is due in part
> to the fact that the system has not been changed much in the last 25
> years!   Introduce long file names, change the character size from 1
> byte to 2 or 4 byte unicode, allow libraries to contain sub libraries.
>  Enhancements like that would be great, but they would likely require
> a source code recompile of programs.
> 
> -Steve Richter
> 
>