30-Year-Old Macintosh SE/30 Gets A Brand New Logic Board

Some time ago, [Bolle] got the idea to redraw the Macintosh SE/30 schematics in Eagle. Progress was initially slow, but over the past month (and with some prodding and assistance from fellow forum frequenter [GeekDot]), he’s taken things a step further by creating a fully functional replacement Macintosh SE/30 logic board PCB.

By using the available schematics, the project didn’t even require much reverse engineering. Though he plans for more modernization in later iterations, this design is largely faithful to the original components and layout, ensuring that it is at least basically functional. He did update the real time clock battery to a CR2032 and, as a benefit of redrawing all the traces, he was able to use a 4-layer PCB in place of the costly 6-layer from Apple’s design.

The board came back from fabrication looking beautiful in blue; and, once he had it soldered up and plugged in, the old Mac booted on the very first try! A copy-paste mistake with the SCSI footprints led to some jumper wire bodging in order to get the hard drive working, but that problem has already been fixed in the next revision. And, otherwise, he’s seen no differences from the original after a few hours of runtime.

Recreating old Macintosh logic boards almost seems like its own hobby these days. With the design and fabrication capabilities now accessible to hobbyists, even projects that were once considered professional work are in reach. If you’re interested in making your own PCB designs, there are many resources available to help you get started. Alternatively, we have seen other ways to modernize your classic Macs.

[Thanks to techknight for the tip!]

One-Off Kapton Solder Masks

soldermask

With the proliferation of desktop routers, and a number of easy methods to create PCBs at home, there’s no reason anyone should ever have to buy a pre-made breakout board ever again. The traditional techniques only give you a copper layer, however, and if you want a somewhat more durable PCB, you’ll have figure out some way to create a solder mask on your homebrew PCBs. [Chris] figured Kapton tape would make a reasonable soldermask, and documented the process of creating one with a laser cutter over on the Projects site.

The solder mask itself is cut from a piece of Kapton tape, something that should be found in any reasonably well-stocked tinkerer’s toolbox. The software for [Chris]’ laser cutter, a Universal Laser Systems model, already has a setting for mylar film that came in handy for the Kapton tape,

Of course, getting the correct shapes and dimensions for the laser to cut required a bit of fooling around in Eagle and Corel Draw. The area the laser should cut was taken from the tCream and tStop layers in Eagle with a 1 mil pullback from the edges of the pads. This was exported to an .EPS file, opened in Corel Draw, and turned into a line art drawing for the laser cutter.

The result is a fast and easy solder mask that should be very durable. While it’s probably not as durable as the UV curing paints used in real PCBs, Kapton will be more than sufficient for a few prototypes before spinning a real board.

A Touch Scroll Wheel Via OpenSCAD

touch

Recent experiments with the Arduino CapSense library led [Bryan] around the Internet looking for interesting applications. He hit upon a very cool touch scroll wheel made entirely with PCB traces, but the geometry – three interleaved zig zags is impossible to build in the decidedly ungeometric Eagle PCB package. One thing leads to another and now [Bryan] has a cap touch wheel Eagle part designed entirely in OpenSCAD.

The touch scroll wheel implementation [Bryan] found came from an ST touch controller datasheet and used oddly-shaped patterns to create a capacities sensor. Eagle is terrible for designing anything that isn’t laid out at a 45 degree angle, so he fired up OpenSCAD to draw these triangles. Importing into Eagle was another challenge, but a quick Ruby script to convert a DXF file into a set of coordinates for Eagle’s POLYGON command made everything very easy.

If OpenSCADing touch sensors isn’t your thing, there’s also an Eagle library full of them – something we found last week.