I made the following patches to SYSTEM:

System  Modification:
124.26  pld:
          (fed:font-char-min-raster-width) does, in fact, exist....
124.27  pld:
          If you forcibly take the 3com controller with (si:set-processor-owning-ethernet),
          you are now warned that unless the former 3com owner is dead, it must do a
          (net:configure).
124.28  pld:
          The code that was added to (zwei:last-resort-possibility) to deal with
          package roots was totally broken....
124.29  pld:
          Peek File System now successfully notices when access type has changed, but didn't
          notice when an access with no host-units acquired some host units.
124.30  pld:
          When you Abort out of Opening a file with FTP-ACCESS, you have to reset the
          host unit -- control/data connection can be in weird states.
124.32  pld:
          Put (ZWEI:CLEAR-ALL-HISTORIES) onto :gc-system-release initialization list.
124.33  pld:
          The buffers used by a TCP buffered stream are now a resource.
124.35  pld:
          The resource matcher for a TCP:SIMPLE-ART-8B-BUFFER now looks for
          array-length = to the specified length, not >=.  TCP really works
          best if the buffers are exactly the length of specified MSS...
124.36  pld:
          Add a few Imports/Exports to NETWORK package.
124.37  pld:
          Create parameter fs:*ftp-access-record-history* to control whether
          FTP commands are recorded
124.38  pld:
          Funny interaction between the process opening a file via FTP-ACCESS and the wholine:
          If one is in the process of doing a probe to get the property list when the other
          asks for the property list, the second gets a NIL.  Not a problem if the wholine is
          second, but can cause an error if the wholine was first.  Add an interlock.
124.39  pld:
          (cli:read-from-string) didn't handle eof-error-p correctly.
124.40  pld:
          If you run with fs:*ftp-access-record-history* set to NIL, you can no longer
          tell exactly what the Server FTP didn't like about your access request.
124.41  pld:
          When a :write-data request failed, a tcp-buffered-stream was losing its buffer.
124.42  pld:
          SUPDUP command <Network> Control-Y to send most recently killed string
          through connection used to require you to type <Network Control-Shift-Y
124.43  pld:
          Fixes found while examining Server FTP error messages:
            - When connection is refused for a tcp-stream, print the host
              name rather than just a raw address.
            - (open "tcp-host:167344452.123") should open host "167344452"
              and remote port "123".  Didn't parse right for that...
            - (tcp-socket :open) with local-port already in use said
              "local-port T already in use" -- backwards arguments to format.
124.44  pld:
          FTP-ACCESS no longer requires fs:*ftp-access-record-history* to be T
          to correctly get the last Server FTP reply.
124.45  pld:
          (zwei:set-lisp-attributes-from-mode-with-translations) requires its
          argument to be a zwei:node, not a zwei:zmacs-buffer.
124.46  pld:
          Don't force user to login to access imagen for screen dump, etc.
124.47  pld:
          Certain User FTP commands (pwd, mkdir, rmdir) have official protocol
          commands (which are tried first) and older commands that are tried if
          the official ones failed.  If the Official ones worked, FTP-ACCESS
          thought the command failed.
124.49  pld:
          Opening a file via FTP-ACCESS with :characters NIL and :byte-size
          unspecified set byte-size to 8 instead of 16.

I also built Microcode version 1757, which makes the following functions NOT
crash the machine when given non-array arguments:
    (COPY-ARRAY-CONTENTS)
    (COMPILER:%STRING-WIDTH)
    (SYS:%IP-CHECKSUM)

and also version 1758 which does the same for (COPY-ARRAY-CONTENTS-AND-LEADER)
and which makes (SYS:ARRAY-TO-BIGNUM) work.