MSI 6800

Hi there, I recently acquired a Midwest Scientific Instruments 6800 computer. Been meaning to set it up but was working on restoring a couple of SWTPC terminals first. It has a SI-1 serial board in it and what looks like a second serial board absent manufacturer markings. The SI-1 has configurable baud rate, but I do not know what the other settings should be (ie. 7 or 8 bit, how many stop bits, etc.). I'm working with a PC terminal for now, and the MSI does react to keys being pressed, but it just produces jibberish. I have the baud rate at 1200 and have tried 7 bits, 1 stop bit, Even parity, odd parity, 2 stop bits, 8 bits, etc.. but no avail. Wondering if there's a manual extant out there or anyone with really good memory on how to get these things communicating. Thanks!! Brad