Hi Chris If it is a 40 pin socket, it is most likely for a 80C187 math chip. I have a several boards that have this socket but only two 80c187's to go with them. These chips still hold premium pricing( ~100-200$ ). The code most likely didn't use the math chip. I've never fiddle with it but I assume it is 87 compatable. I guess one would have to go by package type. Each 80C186 had a slightly different fixed register structure and I/O mapping. If you had the eprom with it, you might try to save the main reset code. This will have the basic setup to get the memory and I/O configured correctly for that board. Once past the reset, just using 8086 code would work well( except know where things like the serial in and out was ). The 80C186 was basically 86 code with a couple enhanced instructions borrowed from the 286. Dwight