Experimenting with Jim's motion software

[Roland]

Hi fellow builders,

Never thought that an die-hard hardware guy like me could endeavor on the software side, but thanks to Jim's website and software files including clear explanation on how to build a cheap software interface, I found out that it is actually pretty simple. I only got stuck with the GWbasic code driving the parallel port. Jim's code line 20 BASE0 = &H3BC and line 1340 OUT BASE0, DOUT seems to indicate the parallel port address is &H3BC. My PC's port does not react on this, but it does work with address &H378 . Seems that not all PC's have the same address for parallel port then?

But with this small modification the whole interface is now running perfectly, and this simple interface method opens a lot of possibilities. Lots of new things to try out !

Thanks a lot for your inspiration, Jim !

Roland

[Jim NZ]

Hi Roland, You are dead right and thanks heaps for pointing this out !! Back in the good old DOS days the LPT port was generally ... (And I mean GENERALLY)
LPT1 &H378 (88
LPT2 &H278 (632)
LPT3 &H3BC (956)

However this was not always the case, so if it didnt work, the other address's needed to be tried.
In general though ... LPT1 was &H378 and I should have changed my code to that and added the other address's in the doc's for anyone that struck an odd one like I obviously have.

The short of all this is to change line 20 to read ...
20 BASE0 = &H378:SP=0:SR=0:CLOSE #1

Remember (for other guys sake) you need to save it as a .bas file and not a .txt file or you will just load the old one again.

A wee snippett I found somewhere...
' Common parallel port addresses are &H378, &H278, or &H3BC
' If you don't know your LPT base address, it is normally displayed
' during the beginning of the boot process. For Windows, you may
' need to press Esc to see the text screen. Press Pause if the
' information does not stay long enough on the screen.

I seem to remember in some Operating systems there is a program called MSD that will identify the base port address for you.

Am updating my site and will insert that in the docs etc. Thanks for pointing it out Roland !! and you are dead right .. it is real easy to get the output to do something.
Wait till you get your relays clicking and clacking as you fly .. Then your heart will really start pumping !!!

You have a great website Roland , a lot of information and idea's there for guys like us.
Can you add your website address to your postings so the other guys can find it if they havent already ???

Keep up the good work and keep us informed as to your progress !!!

Cheers .... Jim

[Roland]

Hi Jim,
Thanks for the clear explanation. Luckily GWbasic is an easy language to play with. With your help and a the famous T&E method (trial and error) I have come a long way. Lots of fun making old PC's actually do something useful. So far haven't spend a dime (I have a large junkbox) but making good progress.
I'm trying to document everything I do as clearly as possible. You can read about my interface experiments at http://www.simprojects.nl/interfacing.htm
More goodies are described as well: Motion platform, experiments with scenery visuals, joystick hacking, flight yoke and flightstick with force feedback, building tactile transducers..... well, have a look at http://www.simprojects.nl

I'll keep you all posted. Have fun !

Roland