pcb-rnd knowledge pool

Abstract: There was a few years after the fork, before pcb-rnd started to use its own native file format. During this transition period the (now pretty much obsolete) .pcb file format got a few pcb-rnd extensions that mainline never cared to implement. One of these extensions is asymmetric "pin shapes".

This feature is obsolete. It is a special case hack, which was an attempt to stay compatible with gEDA/PCB. gEDA/PCB did not do their part of it, so it never achieved compatibility. Instead, pcb-rnd got its own native file format and padstacks, which is a feature that superseds any such hacks with an elegant, generic solution. This node is kept for historic reasons.

The intention behind this feature was to selectively increase the size of a pin or via in different directions. This increases its surface (helping copper to stay on the laminate while withdrawing mechanical stress) without interfering with requirements of tight packing. This feature is similar to teardrops.

As a temporary hack with the old format, a few simple pin shapes can be stored in flags. If the pin has the square flag it may also have a shape(N) flag, where N is between 1 and 17. The shapes are derived by stretching the octagonal shape polygon.

Just like with the square flag, there's only one flag for all layers.

This feature is supported only in by io_pcb, using the obsolete gEDA/PCB file formats. pcb-rnd still supports this feature for compatibility with pcb files saved with previous versions of pcb-rnd. gEDA/PCB never supported the feature. Do not use in new design - use padstacks.

Example: io_pinshape.pcb