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Harmony software and BIOS

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One other thing I'll add is that the cart doesn't seem to be real good at consistent power on initialization. On both the 2600 and 7800 I've tried it on, at times I will have to power cycle the system up to three or four times before getting the cart to come up.

 

I have the same problem, i dont find it that big of a problem as long as it doenst fry the card.

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One other thing I'll add is that the cart doesn't seem to be real good at consistent power on initialization. On both the 2600 and 7800 I've tried it on, at times I will have to power cycle the system up to three or four times before getting the cart to come up.

We are aware of this. We have mitigated the problem but the best we may achieve is 80-90%.

 

The problem is due to the fact that the Harmony has a microcontroller that must start running before the 6507 in the 2600 does. We cannot halt the 6507 so we have to beat it to the punch. In theory, the Harmony should take about 6 ms to start running and consoles should take about 24-50 ms but apparently this isn't 100% certain.

 

This problem should be much less pronounced on Melody carts because they have fewer devices to power and should start and have stable power much sooner.

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One other thing I'll add is that the cart doesn't seem to be real good at consistent power on initialization. On both the 2600 and 7800 I've tried it on, at times I will have to power cycle the system up to three or four times before getting the cart to come up.

We are aware of this. We have mitigated the problem but the best we may achieve is 80-90%.

 

The problem is due to the fact that the Harmony has a microcontroller that must start running before the 6507 in the 2600 does. We cannot halt the 6507 so we have to beat it to the punch. In theory, the Harmony should take about 6 ms to start running and consoles should take about 24-50 ms but apparently this isn't 100% certain.

 

This problem should be much less pronounced on Melody carts because they have fewer devices to power and should start and have stable power much sooner.

 

This may sound strange but what about putting a cr2032 (standard cmos battery) into the harmony with a small switch on the cart to "turn it on" before powering up the console?

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One other thing I'll add is that the cart doesn't seem to be real good at consistent power on initialization. On both the 2600 and 7800 I've tried it on, at times I will have to power cycle the system up to three or four times before getting the cart to come up.

We are aware of this. We have mitigated the problem but the best we may achieve is 80-90%.

 

The problem is due to the fact that the Harmony has a microcontroller that must start running before the 6507 in the 2600 does. We cannot halt the 6507 so we have to beat it to the punch. In theory, the Harmony should take about 6 ms to start running and consoles should take about 24-50 ms but apparently this isn't 100% certain.

 

This problem should be much less pronounced on Melody carts because they have fewer devices to power and should start and have stable power much sooner.

 

This may sound strange but what about putting a cr2032 (standard cmos battery) into the harmony with a small switch on the cart to "turn it on" before powering up the console?

It wouldn't work in this case. Although the Harmony's chip does have a dedicated pin for a CR2032 battery, its only purpose is for the real time clock, which we aren't using.

 

However, while there are ways to throw extra hardware at the Harmony to make it start nearly 100% of the time, we felt the cost would be too great, especially for Melody boards which absolutely have to be minimal to keep their cost competitive. I felt that its current design was a reasonable compromise to allow for a cheap RAM board for homebrews and a SD card multicart we can sell for $50 and not incur a loss.

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I figured that would be the case, just wanted to double check. It's only a minor annoyance as long as repeated power cycling does no harm to the cart.

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It shouldn't. If the cart starts last, it will either enter its ROM bootloader (which floats all buses) or the bankswitch program, which would be no worse than if a game on conventional hardware crashed.

 

If you really want the Harmony to start every time, you can plug in the USB cable while the cart is in the console, then power on. The only problem with this trick is that if you power cycle the 2600, whatever game you started will still be loaded into the Harmony because its power is never interrupted, so you'd need to unplug the cable and plug it back in. I don't think anyone will want to go through all this trouble.

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Got mine yesterday and after the BIOS update I was able to get it to run no porblem, and that's saying something if i can do it ;) Thanks guys, great work!

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2 questions...

 

1. Couldn't a capacitor across the power lines of the cart keep it alive for a second or two, and ensure that Harmony only lost the powerup race once?

 

2. Is there a simple mod one could perform to delay power (or otherwise trigger a wait) in the 6507 itself?

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2 questions...

 

1. Couldn't a capacitor across the power lines of the cart keep it alive for a second or two, and ensure that Harmony only lost the powerup race once?

 

2. Is there a simple mod one could perform to delay power (or otherwise trigger a wait) in the 6507 itself?

 

That's funny, I was just reading this thread and was going to post the same thing as your point number 1 and you beat me to it by about five minutes.

 

Mitch

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2 questions...

 

1. Couldn't a capacitor across the power lines of the cart keep it alive for a second or two, and ensure that Harmony only lost the powerup race once?

 

2. Is there a simple mod one could perform to delay power (or otherwise trigger a wait) in the 6507 itself?

There are 1.0 uF caps on 5v, 3.3v and 1.8v, several more 0.1 uF caps on 3.3v, and a 4.7 uF cap on 5v on the daughterboard. I think the caps are part of the problem, actually, as they do not necessarily charge right away. A large cap would probably just about guarantee a failure on the first power cycle.

 

Further, we actually do not want to keep the Harmony alive. It has a multistage boot process and interrupting power to the 2600 but not the Harmony might put either into an unexpected state.

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