It was supposed to have been the science fiction writer Arthur
C. Clarke who coined the phase
"The technology of any sufficiently advanced
civilization
is indistinguishable from magic."
Finding out how to make the SDS simulators in the demo kit
respond to "virtual hardware devices" took some
considerable experimentation. If you want to know all the gory
details, then read through these web
pages.
For this laboratory it is sufficient to follow some simple
instructions to get the SDS simulator to work with the virtual
devices. If you examine the files you are downloading, the MAGIC
will disappear.Getting the virtual devices to work is very
obvious in hindsight.
- First step is to set up a working directory lab2
into which you will need to download various files.
- In order to get the SDS simulator to correctly respond to
the "virtual device" it is necessary to change
some of its "properties".
- Down load the file tempini.ini
into your working directory.
- There is one line in that file that allows the
SDS toolkit to directly access an editor of your
choice.
- Modify the line echo "alias
_edit visible -n emacs" to
activate the editor of your choice rather
than my favourite "emacs". You
will now find that the Tools
option of the SDS simulator can now be
used to edit a file.
- You may have already done this operation
if you activated
the SDS editor option earlier. You
will need to do it here as the "tempini.ini"
file will replace your changed "sstep.ini"
file.
- The modified tempini.ini file must now
be installed as sstep.ini in the
SDS init directory.
- If you have done the standard SDS
install, then the path to the init
directory is -- c:\SDS65\init
- This new sstep.ini file
modifies the SDS memory model, something
that is allowed with the demo kits only
when you first power up the SDS tool.
The virtual devices require that certain
portions of the memory are
"absent". Due to the other
limitations of the SDS demo kit, the
maximum memory size is limited to the
range 0x0000 to 0x7FFF for this
laboratory. These numbers are reflected
in the 68k
absmap.spc and the PowerPC
ppc.lnk memory specification files
- Down load the files cdemo68k.dbg
(68K Laboratory 2) and cdemoppc.dbg
(PowerPC laboratory 2) into your working directory lab2.
(Files with extension .dbg is to the SDS
simulator what .bat files are to DOS or executable
text files (source-able) files are to UNIX.These .dbg files
are a series of commands to configure the SDS
environment.)
- You might also like to "configure" the SDS
simulator Tool options "assembler" and
"linker". Using these, together with the Tool
"editor" option, means you can now modify,
assemble and link, without leaving the simulator for
MSDOS.
- Configuring
the 68K toolkit
- Configuring
the PowerPC
- WARNING:- I found
working this way very useful from inside
the 68K simulator. However, under Windows
3.1.1, I crashed the PowerPC demo kit
simulator frequently. For the PowerPC
simulator, it remained more reliable to
exit back to a MS-DOS window for editing,
assembling and linking. The SDS PowerPC
toolset was only used for simulation.
- This may be less of a problem in Version
7.X.
- If you have a version of the SDS toolset running,
close and restart it.
- This will allow the new settings to become
active. Also a useful approach after
"configuring" the simulator
"Tool" options.
- The same sstep.ini can be left in place
for all future tasks handled in the Companion.
- ** VERY IMPORTANT -- EFFECT ON LABORATORY 1 **
- Modify the "sstep.ini" file means that
you are limited to 8K of memory when running the
simulator. If you did not modify the Laboratory 1
line
C EQU 0x202200 to be C EQU 0x7200
you will find that Laboratory 1 will no longer
work until you either change the line or remove
the sstep.ini file in the
"c:\sds65\init" directory. If you
change the line, you must reassemble, relink and
then download the new executable file for
simulation.
The final step
I went through quite a bit of experimentation necessary to get
the virtual devices to work on all the machines I have in the
laboratory. We have tested things out thoroughly, but every
body's machine configuration might be different. For example,
what will happen until Windows NT? There is a chance that nothing
will work. Therefore, if you have the same sense of humour as I
have,
the final step in the "MAGIC" is to wave
your instruction sheet over the top of your computer and
issue the magic chant
PLEASE WORK!
Note added in proof. Actually the Version 6.5
simulator does not work within Windows NT . Things look far more
promising with the Version 7.0 simulator, which has, in the full
version, some new, very useful, capabilities and a completely
"new-look" graphics interface. Watch out for a new
version of the Companion using Version 7.X near
Christmmas after I've applied the WIDFI process to check out what
does, and does not, work in the demo kit.
Last modified: July 16, 1996 11:06 PM by M. Smith.
Copyright -- M. R. Smith