What is this system?

Now I have more space in my computer room my elder brother offered me two systems he picked up some years ago. I don't know much about either, but bitsavers has references to one, which is a Texas Instruments 990 with twin 8 inch floppies and a terminal. I have not tried powering it up yet and I dont have any boot disks but it looks interesting. It has a 12 or 13 slot chassis with most of the standard cards present except no printer card. Is this rare, can I get boot disks, would anyone want to buy it, what can I do with it? Much the same questions for the second system but also, what is it. It too has two 8 inch floppy drives, two volumes of manuals for Xenix but no floppies. It is marked "Advanced Micro Computers Inc Microprocessor Development System 29/05". There is a sticker saying Memec Systems Ltd. The front panel is divided into two, one says "Support processor" and the other "Microprogrammed system". Could this really be a proper microprogrammable system or is it just system using a microprocessor. Either way, which programming/microprogramming architecture is it? Any relation to the AMD 2900 bit slice chips? For a couple of months I wrote microcode back in about 1974 but not on this system.