WTD: LC1552B, ITT 492-5 and NatSemi NSA298 data

Hi, Someone's just given me a Commodore Minuteman 3MW (model MM3MW) calculator. The device itself is working fine, but I still need to replace the battery pack and charge connector (the batteries were rechargeable nicad, N size). Anyway, just to satisfy my curiosity, I'd like to get some data on the ICs used inside it - these are: LC1552B / 7438 - looks like the main controller. Has some strange logo I've never seen before - kind of a _/- (a squared off S?) with a circle printed over the top. ITT / 492-5 / 7445 - these appear to be LED drivers. I've never seen a part number like this. BTW, the "7445" is printed vertically, the rest of the p/n is printed horizontally (as normal). NSA298 / NS 436 - the "NS" looks a LOT like one of National Semiconductor's old logos. Did NatSemi ever make LED display panels? Now, to finish satisfying my curiosity, does anyone know anything about the Commodore MM3MW? A schematic diagram or service manual would be nice :) Thanks. -- Phil. | Acorn Risc PC600 Mk3, SA202, 64MB, 6GB, philpem(a)dsl.pipex.com | ViewFinder, 10BaseT Ethernet, 2-slice, http://www.philpem.dsl.pipex.com/ | 48xCD, ARCINv6c IDE, SCSI