Trying to find out what they are called. I remember doing my artwork at 4x with tape and taking it to a guy that had a camera the size of a large conference room to get them reduced to scale and printed like positives on acetate sheets for making PCBs.
What are those sheets called and can I still get them from Gerber data?
I know I moaned when we had to go from black crepe tape on acetate to softw are. I was practiced with tape, new to the software - and its output was lo usy in comparison. If the circuit's simple & the OP knows tape well & rarel y designs a pcb... hey why not. Otherwise do it in software, learn.
On Tuesday, September 10, 2019 at 7:42:27 PM UTC-4, snipped-for-privacy@gmail.com wr ote:
The king of that stuff was Bishop Graphics. They had a system with pin-regi stered mylar sheets, red, blue & black tape that you'd use for solder-side, component-side and both sides artwork.They also had many pre-made footprin ts (in black), and a system of "puppets" which were temporary stickies (thi nk Colorforms) to do your placement.
Many fun(!?) hours sweating over that stuff back in the day.
You are not going to make these from Gerbers, but you can get them printed on film or plotted on mylar or tracing paper.
I remember two people taking two days to check a hand-taped layout. One would call out the connections, the other would trace the artwork. A connectivity+clearance check now takes a few seconds.
Well, I did fall in love once, with the young person working with me to check boards. Proximity effect.
I never missed hand-taped boards. If I asked a layout person "say, could you move that section an inch to the right?" I might get assaulted.
NASA used to lay out boards with ink on vellum.
Does anybody remember Lorry Ray?
I kept a couple of mylar sets around here, to show to the kids.
The Bishop salesmen were thugs. They would hold up an order for pads and tape, unless you agreed to buy all your blue-line supplies from them. Silicon Valley rejoiced when CAD killed Bishop.
ftware. I was practiced with tape, new to the software - and its output was lousy in comparison. If the circuit's simple & the OP knows tape well & ra rely designs a pcb... hey why not. Otherwise do it in software, learn.
lmao, I'd forgotten that. Complex boards were a real hazard in that respect .
I guess that would work with a uv epidiascope. Perhaps even with a lightbox if the ink were dense enough & the tracks not too narrow.
We used a photocopier to duplicate the tape layout onto larger acetate shee ts, several per sheet.
Rubylith was a red plastic film that we stuck to the mylars to make cutout shapes, like ground or power pours. We kiss-cut it with an x-axto knife and peeled away the unwanted bits.
Early IC designs were hand-cut from rubylith on mylar. To simplify life, there were exactly 25 microns to the mil in Silicon Valley.
John Larkin wrote in news: snipped-for-privacy@4ax.com:
I remember the traces being rounded in the early IC layout days. No sharp corners, even at the anular ring matings. All smooth. If we could have had rounded edges on the traces themselves, we would have! Little oval traces running all around... nice and quiet.
Some people made rounded bends with the black tape on mylars, but that tended to creep over time. We overlapped at an angle and cut, so one trace wound up being a bunch os segments.
It was a huge PITA. Literally a PITA, hunched over a light table for days and weeks. Then two round-trips to Lorry Ray in Mountain View, to drop off the mylars and pick up the film.
Documents, like manuals, were similarly inefficient. Write in longhand, give to a secretary to type, correct that a few iterations.
bending it round was quicker, but there wasn't always enough space. One thi ng I liked about acetate & crepe was that tracks could be narrowed where th ey had to squeeze through narrow spaces, and pads trimmed down to accommoda te. Of course narrow meant enormous by today's standards.
I remember the days when even DIL pads were too close, and QIL was a thing. Lots of QIL chips got their legs pliered to fit DIL sockets later.
...get peed off with the secretary etc. With hindsight the idea that one ha d to get someone else to type something seems absurd.
It was an accomplishment to push two traces between DIP pads. I was never brave enough to do that. One was tricky enough.
Doing logic in FPGAs is a big improvement. Multilayer boards is another huge improvement.
I wonder if people will still be soldering parts to PC boards 100 years from now. Probably so.
Early in the PC days, it was accepted that "you'll never get a businessman to type." Now there are no secretaries. Good; it was demeaning, and a huge waste of human resources, to delegate so many women to typing and filing and licking stamps and making coffee.
thing I liked about acetate & crepe was that tracks could be narrowed where they had to squeeze through narrow spaces, and pads trimmed down to accomm odate. Of course narrow meant enormous by today's standards.
yeah :) Now I look at early 80s boards and wonder what folk were thinking l eaving so much of the space bare.
I'm convinced they won't. A whole appliance will be done in one silicon chi p, even at the hobby scale. Silicon because it's so cheap & abundant. I dou bt anything will fail to have embedded electronics.
ng. Lots of QIL chips got their legs pliered to fit DIL sockets later.
had to get someone else to type something seems absurd.
It was crazy. This attitude was even worse... how far society has come
Good secretaries ran their boss's departments, and usually knew more about what was going on than the boss did. Being friendly and polite could pay off handsomely.
They were never paid as much as they should have been. When I was working at George Kent in Luton in the early 1970's the company had a job evaluation exercise and it showed that they ought to be paying their female staff a lot more.
So the report was re-written and the results adjusted to fit the status quo.
On Sunday, September 15, 2019 at 2:04:06 AM UTC+10, snipped-for-privacy@gmail.com wrote :
hip, even at the hobby scale. Silicon because it's so cheap & abundant. I d oubt anything will fail to have embedded electronics.
Programmable analog doesn't seem to work as well as programmable logic. My guess is that low volume stuff with any analog circuitry in it will stil l get done on printed circuit boards.
Any significant power dissipation is hard to handle within a silicon chip, and those bits will have to soldered onto something that may end up looking very like a printed circuit board, though the substrates may get more exot ic than we've been used to.
One board I worked on (for blanking off a low current electron beam) got sw itched to a polyimide substrate because it ran a bit hot - the original epo xy glass board discoloured after a year or so in the field, which worried the customers, but the polyimide didn't discolour.
It's funnny to see news articles about technology. They use old stock photos of 2-layer board full of dips and thru-hole parts.
Things will still need wires and stuff. You can't bolt a BGA ASIC into a box.
I just read a cool book, Code Girls.
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One of them would read encoded German diplomatic messages as they came in. She had memorized the code books and could do the goofy-modulo additives math in her head. One really cute, young, innocent looking kid broke a major Japanese code.
A culture that restricts women is at a 50% disadvantage. At least.
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