High score saves add a lot to the enjoyment of playing classic arcade games. I've added a new page listing all the high score saves available. You can find it here.
I've added a new page on the Cinematronics Vertical Deflection Repair I did awhile back. You can find it here.
The Targ Test ROM aids in the diagnosis of problems with the three Targ PCBs. It includes tests for the game's RAM, ROMs, color adapter board, sound board, controls and dip switch settings.
For additional info or to download the ROM click here.
I've cleaned up my notes about the Asteroids board repair and it now has it's own page here.
I've been working on getting an Asteroids board running which required quite a few repairs. See previous post for earlier repairs....
I think I've found and fixed the problem with the board resetting. The watchdog would reset in game mode but not during the self test.
Self test ran fine with beeps when controls were pressed. I didn't have a picture up as my two monitors still have issues and am just trying to get the game to run blind.
Ran all the tests in the Signature Analysis Guide and all the signatures are correct.
Pulled and verified the roms. All were OK, but the pins were rusty and about to fall off of one of the roms. Burnt and installed a new set of roms.
Checked for shorted pins in the ROM sockets - all OK.
I cut pin 1 of L6 (DMAGO) which isolates the Vector Generator. Game quit resetting and I was able to play a game blind. So the problem was in the VGM - which can be difficult to diagnose.
Turns out the problem was in the Vector Generator Program Counter.
Pin 6 of the LS74 @ D4 was low when it should have been high (the opposite of pin 5). This was a chip I had socketed and replaced previously. When I pulled the chip, I found the output was not dead, but low. Turns out the LS32 @ B9 pin 10 (input from the LS74) was shorted to ground. When I cut the leg to pin 10, the game stopped resetting. I socketed and replaced the chip and was able to play a game blind with DMAGO connected.
In order to create the Space Encounters Test ROM, I converted the Space Invaders Test ROM source code for use in TASM. TASM is an assembler I've been using for development. In the process, I also cleaned the documentation up a bit.
This file is now available for download. It can be assembled into an exact copy of the original ROM or modified for use in other 8080 games. You can find it here.
I've been troubleshooting a Sprint 2 board with a power supply / short issue. I've started a page to document what I figure out. I don't have a main Sprint 2 page (yet), so for now you can find it here.
I'm currently in the process of fixing an Asteroids PCB so I can get a restored Asteroids cabinet I bought awhile ago up and running. The cabinet restore was virtually done, just some minor wiring to be finished and installing a monitor and PCB that was included in the package.
I was given a PCB that was supposedly working along with three parts boards.
When I fired up the game with the board installed it appeared dead- nothing on the screen, no sounds, and the player 1 and 2 lights steadily lit.
I recently bought a 5004a Signature Analyzer and built a connector to supply +5v and GND to the board for testing. This allows me to sit comfortably at my bench for troubleshooting. I was looking forward to testing the board with this new tool. However the nature of the problems found so far were such that the Signature Analyzer couldn't be used. The connector so far has been very useful and is much easier than diagnosing from the back of the cabinet.
This board had a number of problems that I've repaired and detailed below. These problems were diagnosed with a logic probe and digital multimeter.
First, I noticed that the 4016 @ M9 was getting very hot and smelled like burning plastic. I pulled the game's 6502A and, after installing in a known working PCB, found it was bad. Both chips were replaced.
Pressing the reset button had no effect. Socketing and replacing the following chips fixed the reset button:
Output pin 10 of the 74ls14 @ B6 stuck low.
Output pin 8 of the 74ls74 @ D4 stuck low. (this chip might have been OK- see shorting issue below...)
After socketing and replacing both of these chips. I realized that the board's RESET line was shorted to ground, holding the RESET input to the 6502A low and not allowing it to initialize. When I took a continuity measurement on the new socket (no chip installed) @ D4 between pins 7(GND) and 8(output to RESET), I found I had continuity. I verified that on my Asteroids parts boards, none of them had continuity between these pins.
Finding the shorted chip turned out to be more difficult. After cutting each leg connected to the RESET line from every chip on the board. I've found, socketed and replaced a number of chips that were internally shorting RESET to ground:
74ls174 @ N7
74ls174 @ P7
74ls174 @ P10
74ls174 @ D8
74ls08 @ E6
There were four chips in this circuit that weren't shorted:
74ls109 @ A9
74ls259 @ M10
74ls08 @ K6
74ls164 @ K9
Hopefully I'm getting close to raising this board from the dead....
I recently fixed a couple Targ Color Adapter Boards and have added info about the repairs to the Targ & Spectar Color Adapter PCB Repair Log. You can find it here.
The Space Encounters Test ROM aids in the diagnosis and repair of your Space Encounters game. It includes functions that test the game's ram, inputs, sounds, and visual effects.
For additional information or to download the test ROM click here.
More website updates. The big new feature today is comment sections located at the bottom of most pages. Have fun!
I've just finished changing the flash video player used at Outerworld Arcade to FlowPlayer. This flash video player has an improved interface and has a much richer feature set for me to use in the future. It's main advantage, however, is that it now allows full screen viewing of any of the videos here at Outerworld Arcade!
The past few weeks I've been helping someone get their Space Encounters game up and running. One result of this is a test procedure for the game's GAME ON circuit. This circuit determines sound volume during attract and game modes.
You can find it on the Space Encounters Sound Repair Page here.
The past few weeks I've been doing quite a few updates to the site small and large. Armor Attack now has its own page and I've added new information and pictures to many of the other pages. I've also added current eBay listings with keywords pertaining to the page viewed. Oh, and the the buttons to the left should now light up! More to come...
Currently Working On:
The past few months I've been busy on non-arcade work but am back at it and starting to make significant progress on my list of arcade projects.
Yesterday, I raised my non-working Space Encounters PCB from the dead! I used the Space Invaders test ROM that I hacked to work in Space Encounters to tell me which rams were bad. Unfortunately it only tells me the next one that is bad, so I didn't quite know what I was getting myself into. After replacing and adding sockets for eight of the sixteen roms on the board, it passed the ram tests in the Test ROM. After replacing the original ROM, I found the board also had a bad ROM (27). I doubled the 2k ROM image to 4k (two consecutive duplicate images) and burnt it to a 2732. Plugged it in and the game came up! Now just have to finish fixing the two sound boards that I was working on in November!
A few weeks ago I ran my Cinematronics Armor Attack for a few hours. At some point the the circuit breakers blew. After unplugging the game and resetting the breakers I turned the game back on to see the screen image had been crushed horizontally to about half an inch tall. Then, the circuit breakers blew again and as I looked behind the game saw a puff of smoke coming from the back of the monitor. One of the deflection transistors went bad and burnt up a resistor. I'm finishing an article on how I fixed this which will be up soon.