Retrochallenge 2009 Summer Challenge Entry

      Retrochallenge 2009
      Summer Challenge
      Mark Wickens
      30-Jun-2009

                                           Prelude

      So, here we go again, or rather we didn't for the first hour and a quarter. The
      VAX is in the attic, and as I work up there I can't really spend the evening up
      there aswell - for the wife, and my sanity! As I'm documenting this challenge as
      I did the previous one, using ALLIN1, I need either access to my VT320 or a
      laptop with word processing specific LK201 keyboard. Once I get used to the
      commands again I can do updates just on the laptop, but no way for the first
      couple of gos. My brain is pretty much reset overnight, so remembering what I
      did five months ago is a no go.

      I setup my Dell XPS laptop (the replacement IBM X60 tablet is currently with IBM
      getting a new motherboard) with the LK201 connected via the serial port[1] and
      booted SuSE Linux - fairly out dated at version 10.3 but generally nice and
      stable. However, I must have been badgered into installing a new kernel version
      by the SuSE updater. The default kernel configuration doesn't include the lkkbd
      driver module which is required to interface with the keyboard, so it's a kernel
      recompile, which on a (cat /proc/cpuinfo) 'Intel(R) Pentium(R) M processor
      2.13GHz' takes about an hour.

              $ cd /usr/src
              $ make xconfig (and select the lkkbd module)
              $ make bzImage
              $ make modules
              $ make modules_install

      At some point I was seduced by the compiz window manager which uses a native
      nvidia driver to do lots of fancy stuff like transparency and windows which go
      all squidy when you move them (and a whole heap of other useless but pretty
      features). In this case 'compile a new kernel' = 're-install Nvidia binary
      driver again'. Then, finally we got here...

      So, after all that I'm having trouble getting all the required keys working on
      the keyboard, and remembered that I have my own 'cooked' version of the module,
      so once again I'll have to build and install a kernel, although this time it
      should be a bit quicker.

      Look, this wasn't how it was supposed to be. If I want to connect to a VAX and
      use a highly terminal-dependent application I have a number of choices:

      1. Use Linux with a proper LK201 plugged into a serial port (or a supported
         USB to Serial adapter). There doesn't appear to be many people doing this, so
         apart from the info I've provided and that in the comments of the kernel
         module your kind of on your own.

      2. Use Windows with a terminal emulator (best I've found are either Powerterm
         525 which comes with a full OpenVMS distribution). My retro and unsupported
         KEA keyboard which is an OpenVMS layout keyboard sort of works for the most
         part with some keyboard mapping trickery.

      3. Run a serial cable from the DECserver 90TL in the attic down to the lounge
         and use a real terminal. A DECserver 90TL, put basically, is an ethernet to
         serial device that allows you to access the local network using a terminal -
         telnet and LAT protocols are supported.

      4. Install a terminal server in the lounge together with an ethernet hub
         supporting 10base2 (thin-wire ethernet) then plug a real terminal into it.

      In reality Option 3 was my first choice and indeed I do have a cable running
      between a socket in the attic and a bare end in the lounge which will carry the
      signal. However, making up cables sometimes just outfaces me when I'm tired, and
      tonight was one of those instances.

              Having had problems with the 'Find' and 'Select' keys I can
              happily report that having installed the lkkbd.c kernel module
              that I'd modified when I originally started using an LK201 with
              Linux to get all the keys working, and installed my xmodmap entry
              that it's finally playing ball.

      Anyway, a little more on topic, if you want a decent VT320 terminal emulator
      that runs under linux then the veneral xterm is your best bet. The various linux
      terminals provided with kde and gnome are all very well if you require a fairly
      basic level of support, but xterm is the only one that supports the VT320
      terminal protocol well enough to be able to run ALLIN1.

      I can't believe that I'm saying this, but I think I could really use one of
      those USB powered keyboard lights - trying to see the legends on the front of
      the keycaps is next to impossible in this light.

      The Challenge

      So, this time round my challenge is to create a mandelbrot generator in VAX
      Macro - the VAX machine code assembler language. I just have this feeling that
      I'm going to really like VAX Macro when I finally get round to coding something
      in it, instead of scanning the manual and the books I've bought...

      Assuming I survive the Ron Haslam Race School at Donnington Park tomorrow with
      my fingers, arms and brain intact, the challenge proper will begin.


      ENDNOTES

      1. Linux LK