Or those Eurocard connectors that are 30 some-odd pins wide and 3 to 5
pins deep? I doubt they're 0.1" spacing, but they dense and rugged.
The 'Eurocard connector' is probably a DIN41612 connector. The full-size
one is 32 pins long by 1, 2 or 3 rows, and there's a half-size one too
(16 pins long). All are 0.1" spacing in both directions. They come in
solder and wire-wrap versions, and even IIRC, IDC versions to crimp onto
ribbon cable.
IMHO these are a lot easier to use for prototyping than card edge
connectotrs. You don't need to etch and gold-plate a set of fingers on
the PSB
-tony