The Question is:
Is there a hex editor available for OpenVMS?
The Answer is :
The OpenVMS Debugger can be used as a patching tool (hexadecimal or
instruction-level), in conjunction with some basic I/O routines that
are available via the OpenVMS Freeware -- specifically, the ZAP tool
in the RMS_TOOLS area.
You can use ZAP to read a block (bucket) of data by VBN (specify X for
hexadecimal), dump into the debugger with R2 pointing to the buffer,
EXAMINE/INST or otherwise examine or alter the contents of the buffer,
GO to get out of the debugger and back into ZAP, then W to write the