View Full Version : Osborne 1: No internal video

June 7th, 2011, 11:02 AM
This thing has been sitting in the corner for months and now I have someone nagging me to get it fixed.
Simply put the jumper on the external monitor connector port is missing and the internal monitor isn't working. The external monitor (!!!) displays an image (and then shows I have issues reading disks) so the jumper block must be used to redirect power and video from the internal display. Anyone know what the pinout is so I can make a new jumper?

June 7th, 2011, 11:20 AM
Both the service manuals and Thom Hogan's book (http://www.hartetechnologies.com/manuals/Osborne/Osborne%201Technical%20Manual.pdf) say that the jumper block just connects contacts from the top side of the PCB to the bottom side. Nothing fancy--just a 20-position edge connector with the odd and even contacts bridged.

June 7th, 2011, 04:34 PM
Yep. Just a quick solder job and it powered right up.

Now to make it boot. All I got are Executive disks and I can't find any images of the single sided floppies. Actually, did the 1b come with double-sided drives or was that a later option?

June 7th, 2011, 04:54 PM
There are two flavors of the single-sided O1 floppies--FM and MFM. I assume that since you have the 1b, you have the upgraded version.

There were third-party upgrade kits to stuff like 96tpi DSDD formats (e.g. Osmosis), but I think all of the stock O1s were single-sided.

At any rate, if you need images, just ask.