A500 NTSC/PAL switch

[dalek]

One should be enough - I can't think of any object you could use that would get both safely at once.

[th4t1guy]

Is it really safe to use straight alcohol on something like that? I would think it would be safer to use something like DeOxit instead.

[idrougge]

Push with two chopsticks and you minimise the risk of bending pins.

On the other hand, pushing in just one edge may dislodge the chip quicker.

But at least you know now why I recommended this method instead of using a PLCC extractor. If it requires this much force when distributed over a relatively large area, you can gather how difficult it would be to pull them chip out in a safe way using the small hooks of an extracting tool. Unfortunately for us A3000 users, that option is not available.

[Amiga1992]

Originally Posted by idrougge

But at least you know now why I recommended this method instead of using a PLCC extractor. If it requires this much force when distributed over a relatively large area, you can gather how difficult it would be to pull them chip out in a safe way using the small hooks of an extracting tool

Yes, I am very glad I didn't try to use a chip puller with this. I would have ruined something for sure.
I'll keep trying with the two chopsticks. I am just afraid of breaking the socket/creating a bad solder joint.

[Amiga1992]

Well look at that, I might have botched the desoldering fixing job I was doing, but I successfully removed the chip with the two chopsticks method (we could now call this technique "The Mr. Miyagi" ) and I successfully installed a switch to make the pin float or connect to pin 41 of the socket.

Now I have to fix the mess I made with the multiplexer and capacitor so I can test it.



[edit] tested it, works great! Depending on switch position it boots up either PAL or NTSC. Cannot change it on the fly but I don't think you are supposed to. Thanks for all the help!

If I pull up agnus' pin 41 on my rev5 a500 will that fix the screen cut off from playing certain pal games on ntsc? What about installing a newer kickstart with the early boot menu?

Personally I wouldn't mess about with NTSC and PAL. I am pretty sure the vast majority of Amiga games are actually written to run on PAL machines which is why they are generally more desirable than NTSC machines. Its not quite the same as the SEGA MegaDrive / Genesis where a lot of titles won't have timing issues (except us people in PAL Land must then deal with the SPEEEEDDDD difference when in NTSC Mode!) but the Amiga as far as I know is a more complicated beast when it comes to timing so I am not too bothered about the cropped screen and slower gameplay.

Edit* Oh and Hi everyone 1st post and all.

[Amiga1992]

Originally Posted by DaveDoc1984

Personally I wouldn't mess about with NTSC and PAL. I am pretty sure the vast majority of Amiga games are actually written to run on PAL machines which is why they are generally more desirable than NTSC machines.

Correct but also wrong.

Indeed most software is made to be run on PAL machines, even some software that people think is compatible with NTSC because the display is 320x200 actually isn't.

But there are a handful of American NTSC games meant to be displayed in NTSC even if they would work fine on a PAL machine. For one, they'd have an ugly black border below the screen, and second, the picture aspect ratio would be wrong. Example, all the Jim Sachs stuff like Defender Of The Crown is meant to be displayed in NTSC, otherwise it looks squashed vertically.

There's also PAL games that can be run in NTSC to remove the ugly border and increase the speed by about maybe 20% faster or something. This is significant and smooths out lots of games like Frontier or F1GP. I did this plenty. Yeah, image gets stretched vertically, but on those vector games, the speed increase is worth it!

So there are a lot of advantages to being able to switch between PAL and NTSC. 3.x+ users have it easy, since you can change from the Early Startup Menu, and yes, even on 1.3 if you use something like Degrader you can reboot in PAL or NTSC and be done with it, but it is easier if you have a switch that does it for you at boot time and this is an advantage of being able to add it so easily on a rev 5+ A500.

So to answer to BORAT

Originally Posted by boratintheuk

If I pull up agnus' pin 41 on my rev5 a500 will that fix the screen cut off from playing certain pal games on ntsc? What about installing a newer kickstart with the early boot menu?

This will work some times and some times not as I explained above. Some games that leave a border below might not work right with NTSC timing so there's no "fixing" them ,but otehrs like Lemmings 2 o, Friontier or F1GP will work much better in NTSC.

In both cases, installing a physical switch or using the Early Startup menu found on 3.1 (2.x does not allow you to switch PAL/NTSC there), you need the proper ECS Agnus to be able to do so, so that's the first thing to check.

[Amiga1992]

This is weird, today I popped out the A500 from storage, and the switch doesn't work anymore it's stuck in pal.

I checked connectivity between the pin and the socket, and the switch does make it seem like it's working, although it's weird than when supposedly floating, the multimeter doesn't display"1" as is normal when nothing is connected, it shows .700something

I'll have to pull out the chip and see what's up, maybe I accidentally pulled the cable soldered to the chip and it's not doing contact. Time to get that PLCC puller I didn't before.

[Amiga1992]

Let's get back into topic, and can a mod please erase all posts from #30 to #35 because they're stupid off topic and just ruin the conversation?

I opened up the old girl today after getting a PLCC extractor, against everyone's better judgement. I had to try it , and yes it was fucking terrible, I scraped off a tiny bit of the package and stopped trying . Brought back the chopsticks and pushed that bad boy out no problems. So for anyone reading: don't use those! Yes having to dismantle everything to flip the board is annoying, but it is a much safer way to remove the chip.

I now tried everything I can think of and this is driving me mad. The computer will NOT boot in NTSC anymore. I removed the switch connection and tried grounding the pin to other ground points, to no avail, the machine is stuck in PAL. Now I realized that maybe the test pin isn't ground, in either way, i forced a direct cable connection between the socket's bent pin and the chip's leg and it still will not boot into NTSC.

Using software I can flip back and forth between PAL and NTSC without a problem.

More weirdness: I still get .600something on my continuity display instead of 1(infinite) when the chip is floating I removed all solder and stuff, nothing is connected to this pin, what does this damn reading even mean?
I also checked the connectivity of pin 41 on the socket to the motherboard. 100% connected.

Any idea what could be happening here? I'm really stumped. The chip's pin looks fine to me. Could another component have gone bad on one of my many tinkerings with this beast?

[Jope]

I agree in this case, thread cleaned.

I disagree with the PLCC puller hate. Telling people to not use a PLCC puller is bad advice in my opinion. Someone might think about using two screwdrivers in this case, if the correct tool is somehow not recommended, ruining the socket. If the chip is stuck (and these large ones often will get stuck), you indeed cannot just squeeze and hope for the best, as the puller will slip and mar the corners of the chip. Instead squeeze enough that the hooks stay put and start rocking the puller around with moderate force to slowly dislodge the chip.

Of course if the board has the holes in the bottom and you have the time to dismantle the computer enough to get at the holes, poking the chip out through those holes is not bad advice, it works fine and doesn't ruin the socket.

No idea about the internal state of your Agnus, apart from "it's broken".

[Amiga1992]

OK fair point about the PLCC, but

Originally Posted by Jope

Instead squeeze enough that the hooks stay put and start rocking the puller around with moderate force to slowly dislodge the chip.

It seemed like there was no way the hooks were going lo lodge underneath the chip and this is what created the problem. I just had to bring out the chopsticks again.

As for my problem, you think the chip is broken? Really? Everything seems to be working fine, it just doesn't seem to be paying attention to that pin.
Also what could have broken it? I didn't do anything to it besides adding the switch, and that was working fine for a while.

[Sinphaltimus]

Originally Posted by Akira

OK fair point about the PLCC, but
It seemed like there was no way the hooks were going lo lodge underneath the chip and this is what created the problem. I just had to bring out the chopsticks again.

As for my problem, you think the chip is broken? Really? Everything seems to be working fine, it just doesn't seem to be paying attention to that pin.
Also what could have broken it? I didn't do anything to it besides adding the switch, and that was working fine for a while.

The internal connection might have been damaged from the heat and simpy not surfaced until it warmed up, cooled down a few times. Those internal chip wires are thinner than hair. It's a guess but I've have chips go bad from not using some sort of heat sink while soldering.