Trimming pins of a DIP

[Alex Eisenhut]

So I've been tearing 8 bit things apart and I notice that to make a CERDIP EPROM fit on a socket in a Commodore 64 game cartridge, the pins have to be shortened by ~0.5mm.

It looks very regular and machine made, were DIPs available with different pin lengths or was there a kind of pin-cutting press available?

[jpanhalt]

Stick the chip you want to trim though appropriate thicknesses of 0.1" perf board and run a chisel or other cutter, but not your fine wood chisels, across them.  An adeptly held Dremel with a cut-off wheel will do the same.

[ajb]

Yes, tools to form and/or cut leads are an essential part of volume assembly of PTH parts. Whole tubes of DIP components are reels of axial or radial parts could get run through machines to cut and form their leads to the appropriate shape and length before getting inserting into the PCB. Lead forming and cutting capabilities can be incorporated into automated insertion machines so it's just load reels or boxes of parts in the machine and go. That's still a common practice for volume PTH assembly, but aside from legacy designs that are still getting manufactured there probably aren't a lot of DIP ICs moving through machines like that these days.  Things like power supplies that still use a lot of PTH parts seem to be increasingly putting the higher complexity circuitry, including ICs, onto SMT daughter boards that get soldered onto the main PCB--at least where they aren't gluing and wave soldering ICs to the bottom of the board, which is a technique that's been around for a long time.

There are also lower volume manual tools available, like specialty pliers for the same purpose, and even tools for forming IC leads from their raw leadframe state if you're in a REALLY low volume custom package situation.

[Fire Doger]

At my job they have something similar to this.
It has a metal blade on a pneumatic piston which slides beneath a perforated plate.

[Alex Eisenhut]

That's crazy! Well I've never seen anything like that tool. Pin straighteners and lead-frame bender/choppers, sure, but nothing like that.

OK I think I'll just use a pair of cutters for this one chip, that tool looks expensive...

[eugene]

What bad thing would happen if the chip sat a little high in the socket?

[Alex Eisenhut]

Both halves of the cartridge won't fit together. It's not like it's going to space or anything, but it looks goofy.