MegAChip - A500 agnus question

[countzero]

I don't think the pin 41 hack makes the agnus PAL magically. Probably it just asserts the agnus so that it will start in PAL mode.

Also using RGB scart doesn't mean you skip PAL/NTSC. A PAL amiga will still output PAL (50 Hz) and an NTSC amiga will output NTSC (60 Hz).

[alexh]

@ arnljot
Pin 41 does not do the same thing on the 8375 as on the 8372. It is not an NTSC/PAL selector on the 8375 which is why there are both PAL and NTSC chips!!

@ Gilloo
Having both an NTSC Agnus and an ECS Denise does not make your Amiga NTSC! You have to change clock crystals, move jumpers etc. You're just asking for trouble.

@ arnljot
Hold out for a -10 PAL variant.

[countzero]

There is no NTSC/PAL distinction for Denise. Only agnus is different AFAIK (and yes I frequently swapped denise's betwen PAL/NTSC machines).

[alexh]

I meant ECS... too many damn abbreviations

[Zac67]

@countzero

Exchanging the crystals PAL <-> NTSC is only required if you need exact timing (100% video compatibility, genlocking, VCR, ...). I can't imagine monitors/TVs to be picky on this.

For RGB that is. If you're trying to use a composite or Y/C signal, the crystals will have to be swapped (plus the video encoders).

[arnljot]

I found a guy selling them at €50 a piece. But he doesn´t want to ship outside the EEC. Norway is only a part of the EEA

I´ve tried to google to see what pin 41 says on the 8372A and on the 8375... But no such luck yet.

EDIT: Changed £ to €

[Lockon_15]

Maybe you should contact AMIGACENTER in France.
They just might have a piece with your name tag on it...

[arnljot]

@Lockon_15

Thanks, I´ve sent him an email. Lets see what he replies.

[Zac67]

The A500+ service manual just states "GND" for pin 41...

btw: "8375" by itself does not really say which Agnus type it is. There are 1MB types (A500/2000), 2 MB types (A500+/600) and even (rare) 2 MB types for A3000, so a "8375" can just about be any ECS Agnus. The two latter 2 MBs are NOT compatible...

[alexh]

Someone's been reading the Agnus page on BBoAH ;-)

FYI: Some of the information on that page is not 100% accurate, I tried to get it upto date but exact information is a bit sketchy

[arnljot]

@Zac67

Yes I know I was being inaccurate. But it´s such a pain to remember and write Agnus 8375 318069-10 all the time

So I abbreviated, and I shouldn´t have perhaps.

@Thread
Btw, service manuals? Where do we find such documents?

Also, which machine introduced the Agnus 8375 318069-10?

[Zac67]

PM me your email address and I'll send it tonite (~5 MB).

[alexh]

arnljot wrote:
@Thread
Btw, service manuals? Where do we find such documents?

http://en.wikipedia.org/wiki/MOS_Technology_Agnus

arnljot wrote:
Also, which machine introduced the Agnus 8375 318069-10?

A600 PAL

[arnljot]

I've struck a deal with Amigacenter france for the needed Agnus for my MegAChip.

I found the service manuals at several sites when I googled for them, and the A600 SM picture of the Agnus pin outs is not readable. But if it's like the SM of A500 and A500+ it doesn't specify what pin 41 is for.

And the pictures seem very similar.

@alexh
Thanks for your input! It made me go for the real PAL Agnus, rather than experiment

@Thread
Thanks to you also