Aleph and Morphology

Sunday 2 January 2011, 11:30 PM Posted by urbancamo

Decided to get some retro-hardware in to the house from the garage this morning. This process started with my DEC VT340 which is a fairly rare terminal which can do graphics (I've previously posted some youtube videos of it doing it's stuff via gnuplot). Maybe I didn't leave it for long enough to equalize temperature (the garage is substantially colder than the house) but when I turned it on I got a nasty fizzing noise and some flashing. This generally means a breakdown in the High Tension Transformer, which is generally a bad thing. I had a VT420 do this a while back, having only ever turned it on once previously since receiving it, and gave up with any attempts to fix it. I may persue this one a bit further given that it is a substantially more rare (and interesting) terminal. That project is for another day however. So I guess this is a gentle warning for all to heed - if you move equipment between buildings you should allow an appropriate time for the equipment to equalize with the ambient temperature. I have no idea whether that was the issue or whether it was a case of its' time was up, but it's not worth taking the chance, especially anything with HT circuits.

Following the terminal failure I decided that bringing in another terminal, such as the VT320, was a bad idea, so brought in my VAXstation 4000/VLC instead. This is the smallest of VAXen, a two inch high pizza box size unit with a microscopic PCB and diminutive 50 watt idle power consumption. Previously it had crashed a couple of times on me when run over an extended period of time (think days). I'm glad to report that it's been great so far today.

The modest specification of the VLC - 6 Vax Units of Performance and 16 MB of RAM make it a good DEC X-Terminal but a bit underpowered for development. I wanted to see whether I could get the X-Window based Z-Code Interpreter up and running. It uses a variant of the ZIP code that I got working yesterday in VMS-ported form, with an X-Window interface wrapper, so I thought I may be able to create a hybrid of the two source code trees.

First order of business was to install VAX/VMS. The system disk did have a version of VAX/VMS on it but it was a disk originally pulled from another more powerful system and modified to work and as such asked too much of the modest VLC. I installed VMS 7.3 from the OpenVMS Hobbyist CDROM using an external RRD43 drive. The SCSI connector on the back of the box is directly above the AUI port which means I could have either a SCSI cable or an AUI to 10BaseT transceiver plugged in, but not both. Anyway, it was a fairly uneventful install and configure, and not long before it was a fully fledged HECnet node and running DEC Windows (displaying in 1280x1024x8 to an AG Neovo F-419 flat panel), DECnet and TCP/IP. I'm using it now to write this blog message, with a remote XEmacs session being displayed from my linux server.

As for xzip, well, I think I'm nearly there. I had to pick bits and pieces from both the modified VMS-specific ZIP code and the xzip code. The machine I was using for development - BUBBLE - is setup to automatically power off around 11:15 PM. I of course always forget I've set it up this way, but it does mean that I'm more likely to get to bed close to midnight and not into the early hours. So I should have more info tomorrow on how xzip comes up.

I'm also thinking of taking the power supply of the VLC apart to service the fans - they are a little noisy - and also to attempt to locate some replacements (preferrably a bit less noisy).