Universal Disassemblers vs. Universal MIILs

[Lyndon Nerenberg]

In article <e8amX#27Cbjc=eric at snark.UUCP>, eric at snark (Eric S. Raymond) writes:
>P.S. on the Cracker concept:
>
>Does anyone know of something like this having been actually implemented?

Yes indeed! Some friends had this running on an Amdahl under the
Michigan Terminal System back around 1980. The disassembler was
part of a program called Glass that ran on 3270 terminals. Glass
was a "window" onto your virtual memory space. By using the PF
keys, you could "page" forward/backward in memory, or jump to
an arbitrary address. You were also able to toggle between three
display modes: EBCDIC, hex, and disassembly. Glass was aware of
the loader's symble table lookup conventions, therefore it was
capable of inserting symbolic names for system subroutines and
entry points into user loaded code. There was talk of adding
knowledge of symbolic debugger load records, but this never got
implemented.

The program was (apparently) inspired by a similar utility found
floating around SHARE someplace.

Oh yes, you could also use Glass to modify memory contents by setting
the display to hex mode, making changes to the screen, and hitting
ENTER to write the changes. There was also an undocumented PF key
combination that would invoke spells to nuke the hardware protection
bits. Given that the entire OS resided in shared virtual memory,
this feature contributed to some rather interesting evenings ... :-)

*** INLOOP PROTECTION TROUBLE SNARK
*** HELP! SNARK IN MTS!

--lyndon
--