Messing around with a 8031

[Jerry]

I have an old remote control, appears to be for a military weapon loader for aircraft. Probably a prototype since it is serial #001. Pretty neat. Sealed, has about 13 buttons, silicone top, fwd/back,cw,ccw joystick, and lights. Internally it is all controlled with a 80c31. Obviously there is no info on this thing. I traced out the wires, found the analog for the sticks goes right out the MS connector, the button presses and lights are controlled by the uC and talk to the outside world via serial. Tried hooking it up and no activity on serial. The unit uses the 8031 which is a romless version of the 8051 so I yanked the eprom and read it off with a programmer. Dumped that through a disassembler and got the code. I know very little about programming but have gotten a little help from some others. At the beginning of the code it goes into a loop waiting for a 53h from the serial port. I got another 2732a and yanked that subroutine out, recompiled it and burned it. This now lights a trouble light on the front. At least something but the serial is still dead. Hmmm...

I have been drawing out the schematic from the board. It's starting to make sense, the lights and buttons are memory mapped on the buss with 74HC273s and 244s/ The 273 flip-flops outputs are tied to the darlington arrays. One output drives one light. The 244 latches take the input from the switches. Switches are common to ground and pulls the input on the 244 low when pressed. Both the 273s and the 244s are on the bus all in parallel. The clock inputs for the 273s and the enable pins on the 244s are connected to a 74HC138 3 to 8 multiplexer. Outputs 0-2 to the 273s and 4 and 5 to the 244s. Inputs of the 138 are on bus lines A0-2.

Looking at this it seems there is no scanning routine like on a matrix keyboard and the lights are individually driven on the darlingtons so the Pokeys is looking more and more like a winner for this project. It would tie everything together and output a USB HID protocol and even handle the analog from the joystick.

http://www.poscope.com/pokeys56u

If anyone knows anything about this kind of code I can post it. Its a pretty short program.

No real use for this thing as of yet. Just too cool for it not to do something!


Weapon loader remote by macona, on Flickr


Weapon loader remote by macona, on Flickr


Weapon loader remote by macona, on Flickr


Weapon loader remote by macona, on Flickr