Posted by Andy in Indy on December 31, 2001 at 07:48:53:
In Reply to: Hacking the ELS base posted by Bob Sisson on December 30, 2001 at 18:02:06:
: I was brave and took appart my base.
: Weird to begin with.
: The Parrarel port is only using 2-3 bits. I am assuming one line is ground, one line must be the "Data Ready" line so that leaves only 2 lines for data... Weird.
: Ok.. the connections to the Guns..
: Assuming at least 1 pin is for ground, an Xmit, a Rec, and one What ?? Maybe a "sense" pin to tell when to try to talk to the gun ??
This is possibly a clock, but I'd bet that one of the other two is a clock. It is probably a postive voltage, since there is no buffering in the ELS pack. Most programmers require that the power be very stable and in a tight range for programming, and the V2 guns and ELS packs both lack a voltage regulator.
: I figure that they are using something like the stamp chip as it has plenty of I/O lines, and is pretty self contained. This would also make the I/O decing easy as they understand "RS-232" native... Once you "opne" a pin, you can write to it by something like
They are more likely using a 4 bit microcontroller, with just a little bit of RAM (The setup is lost if you power down the pack). This would be the least expensive way to build a gun like that. A weak nitric acid soultion may work to remove the potting without destroying the chip, and expose the chip for identification, but if it is a custom chip, the data may not be available, anyway.
: Send (pin 1, "Test"CRLF)
: Oh well...off to play more with the test equipment.
: If anyone has done any other homework on these it would be appricated if you would share...
Jad Meochy (I can never rememer how to spell his name) was working on some software for the ELS. He is not a hardware guy, but he may be able to refer you to other people working on it.
-Andy in Indy