Running George3

There is also an unmodified section of the Leeds University 1906A Users Manual. The sections on subsystems and on Macros available are specific to the Leeds University system, and do not apply. However, most of the information in §1 to §5 is relevant to any George3 system. There is also reference to George4. This was the virtual memory version of George, and had the same use interface while using paged memory management.

For running MOP you will need a Java runtime system. If you do not have Java on your machine, you can get it from Sun's javasoft website.

Filestore

There are two dump tapes 470001 and 470003 that can be restored onto just 2 simulated EDS60s. These instructions tell how to achieve this.

General System Organisation

Magnetic tapes are held in the tape library which by default is emulated by the contents of a directory called tapes. However, this directory can be redefined, so that the tape images can be read directly from the any directory.

A special file data/config.sys defines the configuration of peripherals. It is headed by a comment that describes its format.

Conventionally, the disk drives start at unit 40, which holds the GEORGE3 exofile. There may be parts of the system that assume this.

Instructions for running George3 from this ZIP file

Starting George with ICL's last vanilla version

1. Create a command window
2. Create a new directory for use as the current directory (say g3run), and do cd g3run.
3. Unzip the zip file into this directory, preserving the path names.
4. Add the bin directory to the path
       e.g.: path %path%;bin
5. Create a telnet window to use for the operator's console, e.g. by use of the telnet command.
   It seems that the telnet has undergone "improvement" in releases of the Windows more recent than mine, and I've yet to succeed in turning off local echo on a Windows XP system.
6. Start the George3 executive emulator by typing:
        g3exec-vc -c FI G3MK8D MGS/tapes/1103663
      This emulates the command FI dd G3MK8D on the operator's console of an ICL 1900, but instead of the unit number, the last parameter is the file holding the mag tape image of the ICLSNED issue tape. The system's response will end with the line:
       Waiting for a console telnet connection
7. Switch to the telnet window and connect to port 1900 on localhost. The system's response will be of the form:
       George 3 operators console: connected
           (which comes from the emulator)
   
       LOADED
   
            This rather terse response is from George's LOADER/ALLOCATOR, its mag tape bootstrap loader.
8. Type: CR 03, and the loader/allocator will read from the file data/CR03 which is emulating the card reader on unit 3, echoing the file's contents as it goes.
9. You should now be asked the question:
       RESTORE?
     to which you should answer: 10696.
10. The system will invite you to mount the appropriate tape.
11. Press control-B. This is gives access to the facility for emulating operator actions. The system will respond with:
        Operator action:-
12. Respond with:
        LMGS/TAPES
             This defines the tape library to be in the directory MGS/tapes. All input on the 1900 console ends up in upper case. The console should now show:
         Operator action:- LMGS/TAPES O.K. Tape library path set -- was tapes
13. To mount the tape, press control-B and reply with:
        M25,470003
         The console should now show:
         Operator action:- M25,470003 O.K. Mounted - read only
14. In due course you will be asked to mount tape 470001. Press control-B and reply with:
        M24,470001
        

At this stage it probably best not to get involved with the Juggernaut job. Abandon it by typing:
    AB :MANAGER,JUGGERNAUTJB

The :MANAGER password is REDLINE. The users :MANAGER and :SYSTEM have been set low security — not what you would expect on a real system.

There is a card reader (file data/CR03b) which contains a job which lists all the users in the system, and their passwords. In order to run it, first erase data/CR03,and rename data/CR03b to data/CR03. Then just engage the card reader — press control-B, and reply with e3. The output appears on the lineprinter, which you will find in file data/LP10.

When you have seen enough, just press F5, and type POST.

When you want to start George up again, do steps 1, 3, 4 and 6. Then replace step 7 with:
     g3exec-vc -c DA GEORGE3
   This emulates the command DA dd GEORGE3 on the operator's console of an ICL 1900,
Repeat step 8 to attach the operator's console, but you should receive the response;
    RESTORE?
  to which you should answer: N

MOP

1. Create another command window and set the current directory to g3run.
2. Start the 7903 with 10 teletypes and 6 VDUs by typing:
       java -classpath bin ICL7903 10 6
3. It will respond with
       Listening for IPB connection
       Listening for TTY connections
       Listening for VDU connections

MOP teletype terminals are just telnet windows, using whatever telnet emulator you please. You connect to the 7903 by making a telnet call to the usual telnet port (i.e. 23). On the machine running the emulator this is easily done by telnet localhost, but you can also call across the net to the machine running the 7903 emulator, and have mop jobs running on multiple keyboards. There is an ICL 7181 VDU emulator which is a Java program that can be run by opening a command window and typing:
    java -jar bin/ICL7181.jar
By default the VDU calls localhost, to make it call another host, e.g. my-g3, type:
    java -jar bin/ICL7181.jar my-g3

It is wise to take a configuration report from the 7903. If the 7903 is running before you get to GEORGE READY, the system will ask you for a configuration report. If not, the first MOP ON should ask for a new spec, i.e.
    MOP ON,57,NS

Emulating the operator's console and the operator

Lineprinter

Card reader

Magnetic Tape

Disc Drives

What doesn't work

The handling of errors in the parameters to g3exec is not right, and often leads to illegal instructions. The simulated command to the George3 exec must be in upper case. Note that there is no unit number in the simulated command. The unit is the first disc specified in config.sys, which is 40 with the configuration supplied. It has never been tested with any other value for the lowest numbered disc.

There is an intermittent problem with MOP ON,57,NS when the configuration contains VDUs. It might be wise to use only teletypes for your first running of the MOP system. Taking a configuration report as part of system start up seems to be OK. In other words the problem has never been seen when the 7903 is started before g3exec, and then the answer Y is given to the query:

On some systems the time is surprising, although the date is correct. George3 appears to be Y2k compliant.

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Updates

It would also help us to know whether you successfully got George to work on your machine, and what difficulties you encountered on the way.