Some help from Google helped me learn more about the loom. It is a Bergman Loom, built by a family of Swedish immigrants in eastern Washington in the 1930s-1960s. They take up relatively little space, with bits that fold in on the front and back. When it's folded up, it's about the size of a standard upright piano. It's quite a bit bigger when opened out, and I'll have to get some old sheets to cover it once I start putting actual thread on there. My cats would have a field day otherwise, and they already think it's a very fascinating jungle gym. Anyway, the Bergman loom is based on traditional Swedish models, and the original model lives in the Nordic Heritage Museum in Seattle. Isn't that cool? I loved going there as a child, and between that and the Selbu mitten collection there I really need to go back. Anyway, I managed to find the original manual that was sent out with the looms, though it feels totally over my head right now. What did we do without google, though? How nice that this info is out there.
I learned that the Bergman is a type of loom called a countermarche loom. Countermarches have two sets of levers, and two ties for each heddle, which allows you to tie it in such a way that each treadle can either lift or lower a heddle. This, along with the fact that it's an eight-shaft, means the possibilities are really endless as far as what I can do with this thing. It also means there are SIXTEEN sets of ties, and things get pretty intimidating pretty quickly. One of the other features of a Bergman is that it has string reeds, not metal ones, which makes it operate more quietly and easily, apparently. I have no idea how old the reeds are on this thing, but they seem to be in decent shape.
Anyway, the next step is warping the thing. It's kind of an intimidating prospect, since I've done this only once before on a "real" loom, at Mistress Giliana's house, with her help/supervision, along with that of our friend Aelia Sophia. The lovely twill pattern I chose for my project (which looks like Brigid's crosses on a diaper background, and is not medieval at all, from what I can tell) should be a fairly easy one to thread, but it does use all eight heddles, and I'm still fuzzy on a lot of this stuff. I know I need to do the tie-up first, and that part is fairly complex, and I also don't really understand tie-ups yet. Add to that that this loom is, according to the internet, notoriously non-ergonomic. There will be a good bit of crawling around on the floor, reaching, bending, twisting, etc. I'm glad I'm young and limber, at least relatively speaking.
Anyway, even though all I have to show so far is a half-read book and a bag of warps, I am making progress in my brain. I'll keep sharing as things actually start to happen with this project.
For now, below is the draft from handweaving.net, from Donat's Large Book of Textile Designs (1895), a German book of a bazillion patterns. Mine will be green and gold. Pretty, eh?