SWTPC 6800 system - chassis

Web page last updated July 30 2025. (c) copyright Herb Johnson. To email @ me, see my ordering Web page.

This is the chassis cover from my 2025 restoration of Bruce Black's SWTPC 6800 system. I obtained this system from him in 2010, look back at it then. Look at all my 6800/6809 work from a page of Web links to that work.

The point of this Web page is to detail the chassis cover of the SWTPC 6800. For replacement or replication, so dimensions and features are essential. Rough notes on construction from sheet perforated aluminum. These are quick photos and measures, I'll update when I can. Thanks to Neil Cherry for his encouraging work on his SWTPC 6800 - Herb Johnson

Advice on cover construction

Essentially the chassis cover is a U-bent piece of aluminum perforated metal, to create top and sides. Such metal was available in the early 21st century. See these following notes from Michael Holley's 2005 recreation:

"The [cover] material is 1/8 inch round hole, 3/16 inch center, 60 degree angle, 0.063 inch thick 3003H14 perforated aluminum. I got a 36 by 96 inch sheet from McNichols Co." The screws are "6-32 3/8 inch truss head screws." The front silver-looking trim is "1/16 inch thick 3/4 inch x 1/2 inch unequal [right] angle [aluminum] at a hardware store. ... The screws are 6-32 3/8 inch truss head screws. " [No detail on the sheet-metal brass fasteners (see my photos)].

The general tricks of construction will be, to fit the result to the corresponding chassis. Fit means the bends line up with the lower chassis, holes line up with holes in that chassis. The cover has notches to fit *inside* the edge of the lower chassis. I do not know if that is necessary in a replicated cover, but if one is obsessed with detail then that means introducing a slight double-bend alond the side edges of the cover. That is a tricky bend.

Seems to me the order of construction events will be:
0) I think cuts and bends will align along the perforations. They do on my original.
1) cut the sheet slightly oversize. Prepare to trim to fit later.
2) perform the two side bends, to fit over the top of the chassis.
3) Trim the bent cover to correct fit over the chassis.

4) Now there's a decision. Do you notch the four corners of the cover, and prepare to "tuck" the edges inside the lip of the chassis? If so, you'll need to make a double-bend to create the tucked edge, and also to cut a 3/4" X 3/4" corner out of the cover for the fitted edge. *Otherwise*, the cover will rest entirely on the outside of the lower chassis, no need for notches or double-bends.

5) Place the cover on the chassis. Locate the screwholes over the screw fasteners on the chassis. Mark the hole locations and drill out the holes. This procedure ought to insure the holes will match up.

6) Perform any additional trims or fits. If the cover needs painting (flat or semi-gloss black), perform the prep and do the painting.

7) Obtain and mount the cover.
8) Remove the cover and hide it, eventually lose it. Most people ran the thing without covers. ;)