Caverot Problem on Windows NT Laptop

[Olly Betts]

In message <002101c056e2$1456bbc0$d785bcd4@mjellistesco.net>, "Martin Ellis" wr
ites:
>I have installed Survex on a friend's laptop which we taking on a trip to
>Thailand at Christmas.
>From a DOS window we can run 'cavern' and 'printhpgl' without any problems,
>but when we try 'caverot' we get the following error message:
>
>16 bit MS-DOS subsystem
>Command Prompt - caverot <cavename>
>The NUTDM CPU has encountered an illegal instruction
>CS:c000 IP:00c0 OP:63 68 6e 6f 6c
>
>[it may say NVTDM - I can't read my handwriting!!!!]

I think it's probably "NTVDM".

>The machine is a
>DEFT version 2.01
>x86 Family 6 Model 6 Stepping 10
>AT/AT compatible
>130,420 KB RAM
>
>and the operating system is
>Windows NT
>4.00.1381
>
>As it is a works machine it has been configured in a weird and wonderful way
>to allow it to be connected to the works network.
The DOS version of caverot doesn't work very well under NT - the problem is
that NT has tight controls on access to the hardware (the graphics card in
this case).  NT emulates a basic VGA card, which means you can't get better
than 640x480 - but that may be reasonable for a laptop display.

Caverot should detect NT and select a VGA mode, but this doesn't seem to be
working for you.  You could try:

caverot --mode-picker cave.3d

This should bring up a dialog box of colours and resolutions.  See if you
can find a combination that works (start with the smaller ones) and let me
know.

To get a higher resolution display, your could reboot into DOS (rather than
use a DOS session inside NT).  Or perhaps better, install Chasm - a GUI
front-end to Survex which Phil Underwood is working on.  It's at:

http://members.nbci.com/bighairyone/chasm/

Cheers,
Olly