[Simh] TOPS-10 question

[Timothe Litt]

On 21-Feb-18 05:49, Jordi Guillaumes Pons wrote:
>> Or, on a reasonably recent monitor, create a pathological name.
>>
>> .path bcl:=dskf:[66,667]
>>
>> This is per-job, but may be easier as it avoids learning to do a mongen/monitor build.  You would have to put it in any batch job that runs bcpl.
>>
> Is that (‘pathological’) the “official” name?
>
> Curiously enough, IBM refers to a similar thing in MVS/zOS as “esoteric”.
>
> Jordi Guillaumes i Pons
> jg at jordi.guillaumes.name
> HECnet: BITXOW::JGUILLAUMES
>
>
Yes.  Simple logical names existed for a very long time.  They provide
an alias for a device, and are associated with that device with .ASSIGN
or .MOUNT commands.  They live in the DDB; a device can have no more
than one.  They don't allow associating a filename or any filesystem
attributes with the name.

Pathological names, stored in funny space, are more recent and much more
powerful.  They provide a search list of one or more device/directories,
can provide filenames and/or filename defaults, and can be specified as
an extension to the "default working directory".  Any number of
pathological names can refer to a single device.

See the PATH. UUO, where the term is used in the documentation.

The PATH. UUO functions are documented, but the path command that
accesses them is not.  This was a budget/political issue with
documentation resources.  The path utility may have been shipped as
"customer supported", but was heavily used internally.

Before you ask: Yes, "funny space" is also a technical term for per-job
(process) executive virtual memory.  Originating with the KI10 hardware,
it's an area of the monitor's address space (32 pages) mapped through
the USER page table.  This means that it is automagically context
switched; the monitor can reference job-specific data at the same exec
virtual address.  Funny space is used to map frequently accessed
context, such as the running program's job data area (a user space page)
and per-job monitor pages (such as the pool from which pathological
names are allocated).   In the KL10, the same effect is achieved with
indirect page pointers.

"Funny" is used in the sense of "unusual", not "humorous".  The effect
is that a monitor virtual address doesn't always refer to the same
memory; the target is context sensitive. 

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