On Thu, Aug 13, 2020 at 4:04 PM John Cowan <cowan@ccil.org> wrote:
On Thu, Aug 13, 2020 at 1:19 PM Henry Bent <henry.r.bent@gmail.com> wrote:
so this damn teeny tiny display would cycle through a sequence of codes that told you what the machine was doing; it came with a book that told you what each code meant. Something like "387" meant mounting /usr. Ugh; I just found a page on ibm.com describing these "IPL codes."

IPL = Initial Program Load = boot(strap), by the way.  It also has the connotations of "toggle in".

Also, "IPL CMS" under VM!

But this reminded me: Does anyone remember a system of any sort where there were *two* corresponding sets of alphanumeric error codes, one short and meaningless like F32 and the other somewhat meaningful like POWER_LOW?  I made up this example, but I have a feeling I saw or read about such a system.  I can't pin it down with Dr. Google.

It wouldn't surprise me if a DEC system had something similar involving random integers and more meaningful error strings.  Maybe something like RSTS/E or RSX?

I already know about plenty of systems that have *numbers* and alphabetics, like <errno.h>, or just alphabetics and a (localizable) text explanation, like VMS, or just a number and a text explanation, like the BIOS errors.

A nifty thing about VMS is that one can type 'help/message' to get contextual help on the last error message:

$ dir foo
%DIRECT-W-NOFILES, no files found
$ help/message

 FNF,  file not found

  Facility:     RMS, OpenVMS Record Management Services

  Explanation:  The specified file does not exist.

  User Action:  Check the file specification and verify that the device,
                directory, file name, and file type are all specified
                correctly. If a logical name is specified, verify the current
                equivalence assigned to the logical name. If the equivalence
                is correct, verify that the correct volume is mounted on
                the specified device and that the file was not inadvertently
                deleted.

$ 

Such number-only error systems are still very common in things like "smart" washing machines, where the cost and unreliability of a non-tiny screen simply isn't acceptable.

My smoke detector beeps three times quickly when it wants a new battery. Yay.

        - Dan C.