Hello everyone,
I recently went dumperster divinging and found a board containing a MAB8031AH12P
Datasheet:Link
I am wondering what could I use it for and if it was junk. I also found some sram and EPROM and logic gates and inverters and voltage regulators and a crystal and buzzer. RAM part number: TC5517AP
Datasheet for RAM:Link
EDIT: Datasheet for EPROM:Link
IF you can use it it is not junk. It depends whether you have a project for it.
8031
Most 8031 variants use, or can be jumpered to use, external Program memory of some sort (traditionally, UV EPROM), and optionally external Data RAM as well. It usually takes about a half-dozen chips in addition to the CPU. Plus a way of programming the program memory.
I've got a bunch of 8031-type CPUs, and have worked through several PCB designs, and basically concluded that IT'S NOT WORTH IT. For less than $3, you can get a more modern 8051 with significant serial-programmable flash memory (like an AVR) and put together a simpler, more capable system, if you don't need much RAM. The only reason to pursue a "real 8031" system is essentially "historical recreation"