On Monday, June 5th, 2023 at 1:43 PM, Robert Feldman via cctalk <cctalk@classiccmp.org> wrote: > > > >Message: 21 > > > Date: Mon, 5 Jun 2023 04:35:28 +0100 > > From: Tony Duell ard.p850...@gmail.com > > Subject: [cctalk] Re: Getting floppy images to/from real floppy disks. > > > > On Sun, Jun 4, 2023 at 10:57 PM Fred Cisin via cctalk > > cctalk@classiccmp.org wrote: > > > > > On Sun, 4 Jun 2023, Rick Bensene via cctalk wrote: > > <> > an example of early "mobile computing". (Tongue firmly in cheek). > > > > The original Osborne 1 had a 12V power input! > > > > Actually it's +12.6V and +5.6V and you have to supply both voltages. > > It's one diode drop to the +5V (logic supply) and +12V (DRAM, disk > > motors, monitor supply), the -5V for the DRAM is produced on the logic > > board. > > > > I am told it was never used and that the Osborne battery pack came > > with an inverter to provide 110V AC. > > > > -tony > > > It (the Osborne Powr-Pac (tm) ) has a what the manual says is a DC-DC > inverter that plugged into a Gould lead-acid battery (or the > cigarette-lighter socket in a car) at one end and the AC input of the Osborne > 1 at the other. I have read on this list that Lee denies that OCC ever sold > them, but I have one that I bought for $50 at Compumat in Chicago on October > 10, 1983 -- I still have the unit, receipt, and User Registration card. It > came with a glossy-printed grey-and-blue manual, like other contemporary OCC > products. > > If anyone wants a copy, I can email you a PDF scan of the user manual. > > Bob
It's funny that luggable power packs come up here as I'm trying to revive my Otrona Attache... The power supply does nothing on AC input, even after a recapping, so I thought I'd investigate the "DC Power Option" described in the manual. Unfortunately I can't find any record that Otrona ever actually *sold* a "DC Power Option", which would plug into an unpopulated 6-pin Molex connector on the back of the device. Interestingly, the header inside the power supply labeled "DC Option" is a 7-pin header, so I'm not sure which pin was "optional" for the external connector! I'd just replace the power supply wholesale with a little ATX supply or something, but the machine needs 5V, 12V, -12V, and 15V; the latter is used to power the CRT and represents a real challenge! I've yet to find anything that outputs all 4 levels at a reasonable price. john
