I always wanted a Dragon's Lair. I don't know why because I rarely played it when it first came out. Of course that might be because they were all broken less than a year later. So when I got into videogame collecting and repairing, naturally I knew it would only be a matter of time before I gave it a try. I started fiddling with the crappy players, cleaning the optics, and screwing with the adjustments. I found that I could get a player working but then the boardset would not talk to the player. I got a list of jumpers and cuts to upgrade a boardset from running the 7820 to the LD-V1000 player and tried modifying them. That turned out to be futile. Well six players and four boardsets later, I've given up. Actually I do have a completely working original which I never play (because I am afraid to turn it on).

Not only have I given up screwing around with the original players and boardsets, I have been seeing a new post every week on rec.games.video.arcade.collecting about someone who needs another player because their's died. To get one working can cost $250 and there are not many places that will work on them.

There must be a better way! So I set out on a lengthy expedition to recreate Dragon's Lair.

First I scoured the hideous pawn shops in search of a newer player, the LD-V4200. Then I figured out how to interface it with my PC. At first I was just going to write the code and put a 286 motherboard in a cabinet and have it run the new player. Then I talked to a guy named Paul who told me that I could just use an HC11 to do the job. So I thought, why have a big bulky PC, when I could put everything on one board the size of a post card?

Next I was going to write some code and design the suitable hardware so that the HC11 would just translate from the DL board to the new player. Then I thought, well that would be a big job to get it right and then I would still have to contend with modifying the old DL PCB. Plus the DL PCBs are getting harder to find. Instead of doing it that way, I have decided to replace everything!

The new "interface" will replace the DL PCB and will run the new player. I am writing new, custom code to get the job done. When I am finished, the interface should run on any of the serial-based Pioneer players that have an external control. There have been a few people expressing interest in getting this thing to run on a Sony LDP-1450. My answer has always been that I don't have one, however interfacing it should be very simple. If someone would be willing to donate one to me, then I could make it happen. A better bet would be to just trade someone my interface for a working LDP-1450. That way I could write the logic and have something to test it out on and in return, someone will get a free "interface". In the meantime, I will not accept a LDP-1450 until I get everything working on mine.

The other game I am thinking about doing is Cliff Hanger. There are a hell of a lot less moves to figure out and I have already figured out half of them. The real challenge for Hanger will be to build the custom overlay screens and overlay hardware so you can see the on-screen hints. It just wouldn't be the same without them.

Current Status:

5/97 - 7/97: I learned HC11 assembly code, built the HC11 programmer, learned how to program it, and figured out how to send commands to the player.

9/27/97: Today I finished writing and testing the logic that drives the LED display board. Works like a champ!

Next I need to add 32K of external eprom to the HC11 circuit which I am hoping will be enough.

10/04/97: I have built the external eprom circuit that I designed with a little help from Mark Schultz. It has some addressing problem which I am looking at. The next step after this will be to look at the sound circuit. DL uses the AY-3-8910 sound chip which is no longer made. I am looking for sources for the chip. If you know where I can get AY-3-8910s in quantity of up to 50, please drop me a line.

11/02/97: I've got the extended mode circuit working. I also have the circuit talking to the player. I've got the demo mode of the game running now.

11/21/97: Last week my hard drive crashed, wiping out the entire project. The floppy that I was backing up to also had it's FAT wiped out so it was lost as well. However, don't despair, I will rebuild. I now have a tape backup.

01/02/98: I got a lot done over the holidays including the complete board layout as well as the random room generator. I also found a suitable production house. Now if I could just get that $%$#@# AY3-8910 sound chip working!

01/04/98: Added a new frame seeking engine that greatly improved seek time.

02/02/98: I can now write to the sound chip but I still cannot read from it. I called Sony to get the LDP-1450 interface manual but they told me that it doesn't exist despite the fact that it is listed in their LDP-1450 operations manual.

03/28/98: I have redesigned the board to accomodate two CPUs. This will eliminate the sound chip problems I have been having by dedicating a CPU port to the sound chip.

04/24/98: Today I got the joystick feedback working so when you press the stick you hear the benevolent beep. I think I will just use a CPU port for the control panel input in lieu of the pesky sound chip.

07/04/98: Haven't done much over the past few months. I have pretty much finished the hardware design and this weekend I took another look at the disassembled eproms. I would like to extract the laser disc and scoring data from the eproms rather than figuring them out myself. Unfortunately, disassembling 48k of Z80 code and making sense of it is not trivial. Have you done this?


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