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Length between the legs on MC68000 for Atari ST

Posted: Sat Jan 02, 2021 1:48 pm
by zChris
I'm trying to design a m68k replacer in KiCad for Atari ST. Since my KiCad does not have M68K chip in its database i have downloaded them from here https://kicad.github.io/footprints/Package_DIP . But now there are several 64legged chips there with different gap sizes between the legs. I think it is 22.86mm that is correct but would like to confirm that with someone more experienced.

/zChris

Re: Length between the legs on MC68000 for Atari ST

Posted: Sat Jan 02, 2021 1:56 pm
by derkom
That's the correct spacing. But you shouldn't need external footprints for it. The Package_DIP:DIP-64_W22.86mm_LongPads footprint provided with KiCad is the correct one. But now that I look, that seems to be the same thing on your github link, so whatever. :D

Re: Length between the legs on MC68000 for Atari ST

Posted: Sat Jan 02, 2021 3:02 pm
by go0se
Here is a 22.86mm 68000 DIP socket footprint in .pretty format for use instead of the standard version supplied in the Kicad footprint libs.

All the spacings are standard but it uses smaller oval pads (X 1.5mm , Y 1.3mm , Hole 0.8mm) to allow additional room to route in between without being excessively minimalist. It also has the advantage of not requiring half a roll of solder for each footprint :)

Re: Length between the legs on MC68000 for Atari ST

Posted: Sat Jan 02, 2021 6:42 pm
by zChris
Thanks for your suggestion. I have been looking around to acquire a socket for 68000. The most common one seems to be with a spacing of 2.5 mm instead of 2.2 mm.

Any tips where i can get sockets with 2.2mm spacing ?

/zChris

Re: Length between the legs on MC68000 for Atari ST

Posted: Sat Jan 02, 2021 8:00 pm
by go0se
I'm not sure I follow what you're trying to do. If you are using a common DIP64 68000 CPU for some purpose then the pitch will be 2.54mm / 0.1" , that is the socket you require unless you are doing something else?

Re: Length between the legs on MC68000 for Atari ST

Posted: Sat Jan 02, 2021 10:00 pm
by derkom
zChris wrote:
Sat Jan 02, 2021 6:42 pm
Thanks for your suggestion. I have been looking around to acquire a socket for 68000. The most common one seems to be with a spacing of 2.5 mm instead of 2.2 mm.

Any tips where i can get sockets with 2.2mm spacing ?

/zChris
Are you perhaps mixing up dimensions here? 22.86 mm is the distance across the chip (i.e. the short dimension). All DIP format 68000 chips are this size. 2.54 mm (i.e. 1/10 inch) is the distance between neighbouring pins, and again is the same for all 68000 DIP chips (and indeed most DIP chips, period).

Re: Length between the legs on MC68000 for Atari ST

Posted: Sat Jan 02, 2021 10:22 pm
by DoG
Also known as 'row spacing'. The distance between each row of pins.
And 'pitch' is distance between each leg/pin.

Re: Length between the legs on MC68000 for Atari ST

Posted: Sun Jan 03, 2021 12:20 pm
by zChris
Aha i see. Thanks for the clarifications.

/zChris