Technology-related projects, tutorials, information, and news. http://www.techdose.com Got the 74F02 Quad 2-Input NOR Gate ICs today -- to replace the IC8 (used for Special Solenoids on the Williams Driver Board). I tried plugging the board in yesterday without IC8 in the board since I was still waiting on receiving the parts -- and i... http://www.techdose.com/viewtopic.php?aid=5925 I got the DIP switches I ordered off eBay. DIP (dual inline package) is a standard package name for components that go into through-holes on a PCB board. DIP switches are essentially a tiny row of switches in little box. They're the small red box... http://www.techdose.com/viewtopic.php?aid=5926 Still working on fixing the Jungle Lord Pinball. Apparently this machine had been sitting in the previous owner's basement for years. It came with a lot of gremlins, so I do wonder if the previous owner ever had it working 100% or bought it with so... http://www.techdose.com/viewtopic.php?aid=5924 I spent too long last night trying to get the 27c512 Eprom working with the Atari 2600. I forgot from when i was messing with Atari Eprom Carts about 8 years ago that most of these eproms need a 7404 hex inverter IC to change the high signal for the... http://www.techdose.com/viewtopic.php?aid=5923 Over the weekend I decided to begin setup on what I needed for testing some simple Eprom bank switching. Basically what I'm shooting for is to use a larger 27c512 (64kb) Eprom instead of the 4kb PROM that's usually found in the cartridges and have t... http://www.techdose.com/viewtopic.php?aid=5922 A few months back I found a bunch of PLCC flash roms I had bought 8 years ago. At the time I was experimenting with Atari 2600 cartridges with the UV erasable eproms. Since the programmer I had was capable of programming PLCC flash roms, I figured... http://www.techdose.com/viewtopic.php?aid=5921 Jameco order arrived, so got the TIP102 and 2n4401 replacement transistors for the Jungle Lord pinball driver board. I cleaned up most of the corrosion (mostly affected left side of the board). Used a 50/50 vinegar & water to neutralize the acid, f... http://www.techdose.com/viewtopic.php?aid=5920 So what are EPROMs exactly and how do they work? How are they different from Flash roms? What's a UV Eraser? I'm sure these are the kind of questions that keep you up all night! Well there's a great article that answers exactly these questions &... http://www.techdose.com/viewtopic.php?aid=5917 The Williams System 7 board I just fixed (with replacing ROMs) was out of a Jungle Lord pinball. The driver board is still messed up from battery corrosion, that'll be next on the list. As it stands, when turned on it blows the solenoid fuse -- and... http://www.techdose.com/viewtopic.php?aid=5916 The day isn't even over yet and I've already used the SA-20 Eprom Programmer to fix a Williams System 7 Pinball MPU board! Can't complain about that one bit! I had been battling with this Williams System 7 board for several days, battling with tryi... http://www.techdose.com/viewtopic.php?aid=5908