A fine machine; spent many happy hours programming these in my distant youth. Not much use without software however; alas, I threw out several boxes of manuals and PPT utilities & games years ago. I do still have a programming manual for it somewhere but, again, not much use without the assembler or at least the M/L monitor. I believe Bletchley has one of these; they might have some software for it. If you're talking about the built-in PPT reader beside the keyboard, that's only used for loading firmware and installing software; basic data I/O uses mag stripe ledger cards, and a small internal HD for RAM. They could have optional PPT I/O however; if you actually mean an external PPT reader (unlikely, since then it would presumably also have a perforator), that might be useful for someone to convert to a standard interface. I still have one or two in case anyone's interested, BTW. If you remove the innards and replace the top they do make sturdy desks or workbenches; at least two of my clients upgraded them that way. Some genealogy: Series F was the original ledger card posting machine; mechanical marvels of springs and levers, rotary accumulators & registers, full numeric keyboard, and a type bar printer, as seen in many banks & offices in the 50's. It was programmed via a removable rack of varying length metal pins; you picked your "op codes" out of a compartmented tray or box (or made your own with a sharp file) and "assembled" them into a program. Carriage movement literally "stepped" through the "program", and the location & length of the pins were the machine language (in the truest sense:) instructions. Parallel processing of a sort, since each program step had multiple instructions; i.e. you would read the keyboard, add & subtract the accumulator and up to 18 registers, and print, all in one operation. Series E added switches and solenoids and connected it to an external fridge-sized cabinet for calculations and core-based RAM; also added PPT and mag stripe card I/O. Except for carriage movement, the programming pins were replaced with "soft" code. L2000-L5000 consolidated it into a desk-sized unit with a PC style A/N keyboard, replaced the moving carriage printer with a dual tractor Selectric type ball, and core with a hard disk. L6000-L8000 replaced the mechanical keyboard & PPT loader with electronic ones, the hard disk with solid state RAM, and added optional cassette I/O & datacomm. L9000 replaced the Selectric ball with a dot matrix printer. B80 & B90 replaced the mag stripe cards with floppies and 5/10Mb fixed & removable HD cartridges and added a display. Since the ledger cards were gone, they then merged into the rest of the B series (B800 etc.) with separate terminals/keyboards and printers. mike -------------Original message: Date: Wed, 12 Apr 2006 18:13:13 -0500 From: "Dave Dunfield" <dave06a at dunfield.com> Subject: Buroughs L5000 available <snip>