In terms of the pictured old pcbs with rounded traces, I wonder if when applying tape "on film" or "on mylar" it was rather easy, when applying narrow fixed-width tape for a track, to bend and follow curves while doing so. Thus, I presume, one could both avoid cutting the tape at bends, and follow smooth curves already drafted by hand.
Here's what came up for me with a search for datak tape:
Tape didn't really like to bend (at least not the stuff I used when I dabbled in old school layout 20+ years ago), for the same reason cars need differentials.
Markers, on the other hand... markers were perfect for that.
I think that's right. I found some envelopes at work with design documents for similar looking boards, and that's how they were made. Drawn on paper, laid out on clear film with tape and adhesive transfer pads, and photographically reduced for etching. One of the envelopes even includes a roll of punched paper tape, which I assume is the drill NC program. I've since re-created the boards in KiCAD, but I hung onto the old documents because they're such neat historical artifacts.
Comments
Great work and writeup.
In terms of the pictured old pcbs with rounded traces, I wonder if when applying tape "on film" or "on mylar" it was rather easy, when applying narrow fixed-width tape for a track, to bend and follow curves while doing so. Thus, I presume, one could both avoid cutting the tape at bends, and follow smooth curves already drafted by hand.
Here's what came up for me with a search for datak tape:
http://www.philmore-datak.com/mc/Page%20274.pdf
Tape didn't really like to bend (at least not the stuff I used when I dabbled in old school layout 20+ years ago), for the same reason cars need differentials.
Markers, on the other hand... markers were perfect for that.
I think that's right. I found some envelopes at work with design documents for similar looking boards, and that's how they were made. Drawn on paper, laid out on clear film with tape and adhesive transfer pads, and photographically reduced for etching. One of the envelopes even includes a roll of punched paper tape, which I assume is the drill NC program. I've since re-created the boards in KiCAD, but I hung onto the old documents because they're such neat historical artifacts.