Mini Megi chip

[Speelgoedmannetje]

Has anybody used this chip? And what are your experiences with it? Experiences like (backward) compatibility and so?

[Speelgoedmannetje]

And btw. what's the use of switching to PAL everytime (acting blindly because of the NTSC video output, or not working at all)? Is there no jumper on it to set it to PAL?

[save2600]

No, those are new and sourced with NTSC 8375's which were made more widely available than the 8375 PAL Agnus (as evidenced when a European retailer only sells NTSC merchandise). Good price! May as well pull the trigger on it and deal with the switch. When used in an A2000 though that has the PAL/NTSC jumper, that might be a way to force PAL mode upon startup.... can anyone confirm this? I don't see why not though since the chip DOES do both modes. Come to think of it... even in an A500 can you force PAL mode on this. Just have to cut a trace going to her. There is a link here I believe if you do a little searching.

To answer your question about compatibility... I've used the DKB version and never had a problem. All the programs and games I used all ran fine or better than 1MB CHIP!

[amigakit]

We also have stock of the NTSC version here (new stock): http://amigakit.leamancomputing.com/catalog/USD.php?url=product_info.php?products_id=915

We are working hard to source the PAL version (watch this space)

[Zac67]

When used in an A2000 though that has the PAL/NTSC jumper, that might be a way to force PAL mode upon startup.... can anyone confirm this?

PAL / NTSC switching by jumper simply works by pulling down pin 41 (_TEST) for NTSC which is otherwise pulled up internally (PAL). On the 500 you can create the same effect by slightly bending the socket contact (for PAL). Some 8375 ignore this signal and therefore are not hardware switchable.

Why CSG even bothered producing two different chips when they already had an established way of preselecting the mode would be a good question. As would be why the made so many different versions of Agnus...

[Speelgoedmannetje]

PAL / NTSC switching by jumper simply works by pulling down pin 41 (_TEST) for NTSC which is otherwise pulled up internally (PAL). On the 500 you can create the same effect by slightly bending the socket contact (for PAL). Some 8375 ignore this signal and therefore are not hardware switchable.

Why CSG even bothered producing two different chips when they already had an established way of preselecting the mode would be a good question. As would be why the made so many different versions of Agnus...

So I could also solder a wire on pin 41 to a ground to get a PAL if it isn't ignored?
And btw. is the chip by any chance socketed? I can't really see it on the pictures. I ask this because I do have an (IIRC PAL) super Agnus chip, but I couldn't manage it to work, and cutting traces on my A500 board isn't my favorite hobby, thank god I could repair that with a little blob of solder.

[Speelgoedmannetje]

To answer your question about compatibility... I've used the DKB version and never had a problem. All the programs and games I used all ran fine or better than 1MB CHIP!

Ah thanks , I'll buy it when I've found out how to force the PAL mode.

[alexh]

You will have compatibility problems compared to the ultimate KS1.3, 0.5Mbytes Chip + 0.5Mbytes Fast RAM.

If you already have 1Mbyte Chip RAM then you probably have already experienced all the incompatibilities you'll ever experience.

Unlike earlier Agnus chips it is not possible to force an NTSC 8375 into PAL mode.

[Antti]

Unlike earlier Agnus chips it is not possible to force an NTSC 8375 into PAL mode.

Just for curiosity, how does the early startup menu switch mode from ntsc to pal?

[VingtTrois]

PAL / NTSC switching by jumper simply works by pulling down pin 41 (_TEST) for NTSC which is otherwise pulled up internally (PAL). On the 500 you can create the same effect by slightly bending the socket contact (for PAL). Some 8375 ignore this signal and therefore are not hardware switchable.

Why CSG even bothered producing two different chips when they already had an established way of preselecting the mode would be a good question. As would be why the made so many different versions of Agnus...

Only  "VBB" model of AGNUS 8375 can switch PAL/NTSC? I'm right?