This is a small new side project, to gather feedback and to see if anyone would be interested in such a thing.
Some (a lot?) of people building Neo-Geo cabs are almost obligated to skip the dual 7-segment credit display because of the rarity/cost of the MV-LED board (judging by eBay auctions), a lack of support in MAME or simply because they lack the knowledge to build their own board.
These are all the reasons behind Sim-MV-LED.
Now, before I go any further, let me say two things:
- Sim-MV-LED is
not a replacement for an original MV-LED in a real MVS cabinet. The pcboard will probably be different (unless someone can give me the measurements for both the vertical and horizontal MV-LED boards). Even if it is the same size with the same mounting holes, there is not going to be any MVS connector on it. It will only have power, token mech switch, player start button and player start input connections.
- I know that MAME devs are opposed to credit displays/counters. However, Sim-MV-LED will have some flaws that would prevent it from being used successfully in a commercial setting.
Here are the features for Sim-MV-LED:
- designed for home users who want to have a more realistic-looking Neo-Geo cabinet
- connects to your token mech switch (or credit button)
- counts from 0 to 99 credits (any additional credits are not only not displayed, they are not counted at all)
- connectors for "player start" button.
- connectors for the actual "player start" and "coin" inputs on your cabinet/i-Pac/keyboard/whatever.
Usage:
In short, the Sim-MV-LED sits between your "player start" input and your "player start" button. Pressing the button will cause Sim-MV-LED to send the player start command to the system but only if there is any credits left.
The upshot is, credits will be kept between games. This is a big no-no for the MAME devs.
However the downside is, and that is a big one, Sim-MV-LED has no idea if the arcade/computer is accepting the player start command or not (ex: if you are in a game selection menu, credits will be taken for pressing player start... same thing if MAME is running but player start has no effect in the game, i.e. you're playing, you're not dead, pressing player start does nothing in the game but Sim-MV-LED will still remove a credit for pressing player start).
If that's not enough to prevent usage in a commercial setting, it also makes it a tool to easily detect if MAME or any other emulator is being used in a commercial setting. That makes it an additional deterrent for using Sim-MV-LED in a commercial cabinet IMHO.
For a home setup, however, it should be more than enough. Just tell your friends to not press "player start" unless the game asks for it, otherwise they'll have to insert another token/press the insert credit button again. No biggie, in my opinion this small downside is worth it to have working credits displays.
As for the hardware, the 7-segment module should be a
ROHM LB-602VA2. I think the original MVS cabinets had red, 14.3 mm (0.56 inches) tall digits.
Can someone with a MV-LED board confirm this? The connections for everything are probably going to be via
OSTTA024163, the same as most keyboard encoders, etc. The power connector could be the same as a PC hard drive or floppy drive.
I'm sure my explanations could be a bit better, but hopefully it's still clear enough that those who are interested will get the idea. If not, I'll do a picture of how it's going to be connected in a typical setup.
As for the cost, it would depend on how many people would want one. Prices for parts and pcboards depends a lot on quantities. And people with two players cabs will probably want two boards.
I'll keep a list, in this first post, of those would be interested (number of boards):