On 2012-10-18, at 15:27, Jim Brain wrote: >>>> http://dl.dropbox.com/u/58002657/cbm/c64/rom_adapter_pcb_1.png >>> Seems like you could put the EPROM socket closer to the 24 pin header, turn the TTL logic 90 degrees, and shorten the board by half. >> Are you sure? Have you noticed the two "pinfoots" called _BASIC and _CHAROM. Do you think you can cut the size by half without moving those two in relation to the 24 pins? >> > I thought these were pads for "flying leads". Since they are not, how would they connect to the sockets underneath? Press-fit? > > No, if they aren't flying leads, the board has to be as long as the distance from CHARROM to BASIC. But, for a production board, I am not sure press-fit operation is ideal. The idea is as follows: - you have ROMs socketed -> you remove your ROMs from the sockets and put the board in their place, done. - you have ROMs soldered -> you unsolder the ROMs and solder the board in their place, done. [*] I made it this way exactly in order to avoid extra wires aka flying leads. What I tried to reduce a bit the size was to put the EPROM socket on the _other side_ of the 24 pins and turn the LSs. While this allowed 0.15" size savings on the left side, I ran into placement and routing complications even with vertical pullups. So I left it this way in the end. Press-fit in the sockets supported by 24 pins and two extra "legs" on both sides should be more than enough stable. Soldered-in will be rock solid /me believes. * - Of course I would use the opportunity to solder precision sockets instead of the board in such case but OMMV ;-) -- SD! Message was sent through the cbm-hackers mailing listReceived on 2012-10-18 19:00:31
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