I distinctly remember an article in the german CT magazine, a couple of years ago. It described the development of the G1, G2 and G3 computers of the Gottingen university at the end of the 50 and throughout the sixties. They also used a drum, and the article described how they coated the drum with the mixture of oxide and -something- with a normal painter brush, by hand... That -something- is mentioned in the article, I forgot what it was. Several attempts were required to get the correct thickness. Distance between heads and drum was measured using cigarette paper as a shim.... Jos

--- On Tue, 11/25/08, William Donzelli <wdonzelli at gmail.com> wrote: There are any number of substances then if you're going to go that low tech. What about varnish or polyurethane then? FWIW, most hobby shops (if there are any left) and some good hardware stores sell K & S brass (and sometimes aluminum) shapes/metal stock. You can buy a pack of shim stock for about 4$. Contains either multiples of .001" thick sheets or varying thicknesses from .001" to .005". Can't remember exactly.

Some are epoxies, some are polyurethanes, some are alkyds. Our (ship) experience has been that the epoxy paints are the best. just be the toughest paint known to man. -- Will

As an aside, one of the common cigarette papers in the UK (I forget which one, but I can trivially look it up) is almost exactly 1 thou (0.001") thick. A common trick of machinists doing not-too-accurate work is to lick a bit of such paper and stick it to the workpiece, then bring in the cutting tool (machine running) until it just scrapes the paper. The cutter is then 1 thou from the work and you have a reference point for the feedscrew. -tony

I'm not familiar w/them. Want it though. And now! I can't even locate a Tandy 6000. What's up with that!!! --- On Tue, 11/25/08, Mike Loewen <mloewen at cpumagic.scol.pa.us> wrote:

On Tue, Nov 25, 2008 at 5:16 PM, William Donzelli <wdonzelli at gmail.com> wrote: I subscribe to the 3000 mailing list, and there seems to be one other complaint... licensing the OS. I am no expert on the matter, but I've gotten the impression that HP can be a real bear to deal with when it comes to licensing the OS for users. It simply can get too expensive for a hobbyist to run MPE... Trust me, I'd love to have a small 3000 at home and if one ever shows up, I'll snap it up if I can. They just seem to be pretty rare on the used market. Mark

It is possible to find 3000's out there..just not as many of them. There are still a lot of shops running them and with HP no longer marketing them, shops running them are often picking up spare systems and parts just in case. I don't think OS licensing is much of an issue..I believe that the OS is licensed to the hardware, so it can move with the hardware. Pricewise, 3000's often cost many times what the equivalent 9000 would cost, even though the hardware in the later systems is identical..just a little switch in firmware telling the box to be either a 3000 or a 9000. -Bob bbrown at harpercollege.edu #### #### Bob Brown - KB9LFR Harper Community College ## ## ## Supervisor of Operations Palatine IL USA #### #### Saved by grace -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Mark Davidson Sent: Tuesday, November 25, 2008 7:28 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: HP3000 On Tue, Nov 25, 2008 at 5:16 PM, William Donzelli <wdonzelli at gmail.com> wrote: minicomputer). I subscribe to the 3000 mailing list, and there seems to be one other complaint... licensing the OS. I am no expert on the matter, but I've gotten the impression that HP can be a real bear to deal with when it comes to licensing the OS for users. It simply can get too expensive for a hobbyist to run MPE... Trust me, I'd love to have a small 3000 at home and if one ever shows up, I'll snap it up if I can. They just seem to be pretty rare on the used market. Mark