Replacement board for old failed DIL Custom Logic - Page 1
Forum section: electronics / projects

author: NivagSwerdna
author_rank: Super Contributor
timestamp: January 24, 2018, 12:36:00 pm
content: I'm dipping my water into the pool that is vintage arcade games...Many old arcade games have custom ICs, normally in standard DIL packages which are now unobtainium.Assuming I can reverse engineer the logic from a working device I would then build a small PCB which would hover over the part to be replaced...... asumming the old part is replaced with a DIL socket...What is the recommended way to get from my PCB to present as a set of pins that fit into the socket?Are DIL headers i.e. things with pins on two sides available for 40, 28, pin packages? Any recommended sources?Is there a better way to do it?Thanks in advance.

author: David Hess
author_rank: Super Contributor
timestamp: January 24, 2018, 12:55:12 pm
content: They make pins which go on the bottom of the board that will fit into a standard IC socket. They have to be long enough to allow the board to overhang adjacent parts.

author: Kevman
author_rank: Regular Contributor
timestamp: January 24, 2018, 01:52:55 pm
content: Working on arcade machines? Prepare for frustration- they're typically... not that well engineered... And complicated. And chip failures are super common since there'sso damn manyand a lot of them run shockingly hot. I once saw a Z80 that literally unsoldered itself and fell out!Anyway, what you're doing is not that uncommon in the industry. One thing that comes to mind is the Braze board:http://www.brasington.org/arcade/products/hs/bzone/This one plugs into the CPU socket, the CPU plugs into it, and then all 6-8 EPROMS on the arcade PCB are suddenly no longer needed.This is a picture of the bottom of the Braze board, where it plugs into the original CPU socket. I think its just round header connectors:http://www.brasington.org/arcade/products/common/header1.jpgAn example of chips that could use replacement are the Atari Slapstics- an address bank controller that doubles as a security device. They differ for each game that uses the board, so there aren't really many more out there than there are arcade cabinets for a particular game.Keep in mind that any Reverse engineering of such devices may have already been done- Most of this documentation is literally the MAME source code for the chip emulation. MAME is your friend.

author: Kjelt
author_rank: Super Contributor
timestamp: January 24, 2018, 02:13:31 pm
content: I don't know how big the DIL socket is but for some you can buy flatbandheaders in that format.Good thing is your board can be placed further away where there is more room, bad thing is since the wires get longer you might run into other troubles.

author: Benta
author_rank: Super Contributor
timestamp: January 24, 2018, 03:36:22 pm
content: I normally use these Preci-dip types:http://www.precidip.com/en/Products/DIL-SIL-TO-Sockets/pview/150-PP-XXX-00-106101.htmlhttp://www.precidip.com/en/Products/DIL-SIL-TO-Sockets/pview/150-PP-XXX-00-XXX101.htmlNo affiliation.

author: edavid
author_rank: Super Contributor
timestamp: January 24, 2018, 05:19:04 pm
content: These flat pins are a good solution. They work well in all types of DIP sockets. I guess they are less rugged than round pins though.http://www.dasarodesigns.com/product/batten-and-allen-ba3760-dill-leadframe-dip-pcb-edge-clip-pins/

author: martinator
author_rank: Contributor
timestamp: January 24, 2018, 08:18:09 pm
content: You should head on over to UKVAC.

author: Benta
author_rank: Super Contributor
timestamp: January 24, 2018, 10:12:11 pm
content: Quote from: edavid on January 24, 2018, 05:19:04 pmI agree, those are nice as well, but mostly suited for direct soldering onto a carrier PCB. Problem is, you need to cut them, which always gives a ragged point/edge which damages the socket plating. Also, you're limited to working inside the DIP "envelope".The ones I linked to have machined pins. Also, they're suited for plug-in modules that are larger than the IC outline.Depends on the application, I guess.

author: james_s
author_rank: Super Contributor
timestamp: January 24, 2018, 10:23:12 pm
content: Before you go too far developing your own, look around. There are a number of products out there to do exactly what you propose, most use CPLDs on a small carrier board.I work on arcade boards myself and find it to be rather pleasing, not all of them are poorly designed, I particularly enjoy working on the Atari stuff.