Championship Sprint - LED output

[matsadona]

Hi

Anybody knows what this LED output is intended for at the Championship sprint game?
In my cabinet nothing is connected, but maybe others have?
Did anyone test when it's active? My guess is that it was intended for displaying credits, like on the volcano buttons on older Atari games...

[SavannahLion]

You're probably about right. It's too late for me to dig through the schematic much further, but I can see that !P2RESET is fed from the Coin Counters block and !LEDS is clocked from the Address Decoding block. I'm not sure where DB2 and DB3 are coming from though. DB0-7 is part of a data bus spanning 4 different sheets, see sheet 6A for the connections to the 6502. The only thing I can figure is it's either a typo and they neglected to change or note what the stray DB* connections are or they didn't bother with noting that it's part of the DB0-7 lines because they're simply single connections. I really don't know since I don't have a ton of experience reading these older schematics. Try understanding the Atari 2600 T.I.A. schematic for some real evil ---steaming pile of meadow muffin---. (Is * shorthand for a pull-up or shorthand for a 1 bit buffer? I think the former, most seem to think the latter.)

But I digress. Given the limited amount of time I invested in looking over the schematic, my initial guess, given the time frame and the hand-drawn nature, that DB2 and DB3 is indeed from the latched lines from the 6502. I don't see any indication that this circuit is part of a daughter board. According to schematic, the LS175 is in position 5F which appears to be on the mainboard.... unless I've overlooked something? What's not connected?

I wouldn't trust my initial judgement on the matter though. I invested all of like 30 minutes into it.

[matsadona]

Thanks for your reply.
I referred to that nothing is connected to pin 3 & 4 (the leds) on the 106 connector in my game. Maybe there is someone else the actually have something connected (like flashing start buttons)?

I’ll just try to hook up a LED and see what happens some day when I have some spare time.

[SavannahLion]

Oh duh, I overthought that one.

Yeah, just connect them and watch the voltages (don't draw from mains or something) and see what happens. I can't recall ever seeing a CS with any sort of status indicator. But by the same token none of them were in the best shape.

[matsadona]

Well, with a standard LED and +5V at the other end, it should be safe, considering that there is a 220Ohm resistor in series. So, approx 22mA. I really have to try if this is actually implemented in the code, not just a hardware feature not used...

[SavannahLion]

It's possible. I noted that CS was also sold as a conversion kit to Paperboy. If they share the same system board, it might simply a holdover from that. It's been so long since I played PB in the wild that I can't recall if it had status indicators either.