Based on the Motorola 6809 microprocessor, and quite similar to the earlier SwTPC 6800. It was still limited to the 64K address space, but the '09 was quite an improvement over the older 6800. It used a slightly updated version of the SS-50 bus.

All the SwTPC 6809's that I've seen (since starting to pay attention) have had "SWTPC 6809 Computer" printed on the back face, in the lower right corner. One of them also had a "boiler plate" sticker giving the model number as "69/A" and the serial number.

Physical description

The cabinet consists of a rectangular metal box of two pieces. The top piece is just heavy sheet metal bent to form the top and left and right sides. It is painted black. The bottom piece is more complicated, but forms the bottom, front, and back; and the left and right sides up to about half of the height of the rest. It is made of some dull gold-colored metal, and not painted. The front face is covered by a thin silver-colored metal sheet (looks like brushed aluminum to me), with a black plastic stripe running horizontally across the entire width. The back face has cutouts for the fan, and for back edges of the I/O cards. The top piece simply slides over the bottom, and two screws attach each side to the bottom piece. It is very solidly made. I could jump up and down on it, with no chance at all of damaging it.

S-Bug monitor ROM
MP-09B CPU board
MP-B3 mother board
8" floppy-disk drives
CDS-1 hard disk

(remove all "x"s to get a valid address)