Amiga hardware info, help and support with a focus (but not limited to) North American NTSC experiences. Open to all.
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A10001986

by A10001986 posted Wed Oct 03, 2018 10:25 pm

I'd bet the Indy ECS works. It only grabs the signals and does its own Denise-emulation.
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A10001986

by A10001986 posted Wed Oct 03, 2018 10:27 pm

nonarkitten: the ones you listed are for 2MB chip ram.

For only 1MB, there are other options. However, as the 8372A is widely available, there should not be a reason to crack heads over which 8375 replacement is the correct one for a particular case.
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intric8
Seattle, WA, USA

by intric8 posted Thu Oct 04, 2018 1:39 pm

@nonarkitten, in addition to what A10001986 said, SEA-CCC member Christian sent me a lot more info you may find helpful and interesting. To be clear, he's keenly focused on the 2MB options.

Christian:

2 MB Agnus types for Rejuvenator boards
Agnus (2MB) 8372AB 318069-03 A3000 (PAL/NTSC), A3000T (PALNTSC)
Agnus (2MB) 8375 318069-19 A3000 (NTSC), A3000T (NTSC)
Agnus (2MB) 8375 318069-18 A3000 (PAL), A3000T (PAL)

The 8375 varieties need to have the NTSC/PAL selection jumper OPEN and need to have 0.1microFarad ceramic capacitor soldered between the Agnus facing pin of the NTSC/PAL selection jumper and ground. (That is the official rework from Commodore to use those in the A3000).

The 318069-03 can be defaulted to either NTSC or PAL using the jumper. The 318069-19 defaults to NTSC as the selection pin for NTSC/PAL is not bonded out (and is internally grounded)and that pin is instead used for the base bias voltage generator that the 8375 Agnuses use - which requires the 0.1 microfarad capacitor. The 318069-18 defaults to PAL as the selection pin for NTSC/PAL is not bonded out (and is internally pulled up to +5V) and that pin is instead used for the base bias voltage generator that the 8375 Agnuses use - which requires the 0.1 microfarad capacitor.

...

You can use the 318069-18 in the US without any problem. It's the same chip as the 318069-19. Only difference is that the Early Startup Menu and booting without Startup-Sequence defaults to PAL (can switch by pressing a key for Early Startup, and run a program from the CLI to switch). Really only a (minor) problem if you have a Microway Flicker Fixer as those are either NTSC or PAL (you won't be able to read while Agnus outputs 50Hz/PAL screen). Screenmode prefs allow you to set the Workbench to NTSC with the -18 and vice versa to PAL with the -19. The NTSC/PAL versions use the same die anyways, all that grounding/pulling up (internally or externally) does is to set the Agnus chip id register to either indicate NTSC or PAL. AmigaOS selects the actually video mode when it initializes the chip. More info.

The only Agnuses that are do not support both NSTC and PAL are the 512k chip mem varieties: 8361/8367 (A1000) and 8370/8371 (A500/A2000 OCS).
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Christian

by Christian posted Thu Oct 04, 2018 2:09 pm

I'd like to add that I have on Amiga that has a PAL 2 MB Agnus (8375VBB 318069-18) in one of my Amigas just like A10001986. Works perfectly, the only weird thing is that Sysinfo and other benchmark programs get confused because they assume 'PAL' Agnus = 7.07 MHz clock (28.375 MHz oscillator for PAL machines) instead of 7.14 MHz clock (28.636 MHz oscillator for NTSC machines). Throws the performance calculations off by about 1%.
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nonarkitten

by nonarkitten posted Thu Oct 04, 2018 6:54 pm

intric8 wrote:And holy smoke! Wait till I get a chance to post the pics from our tests tonight. You guys are ALL going to really like what you see. :)

Augh! I cannot wait, I'm dying from a lead-in like that!!!
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intric8
Seattle, WA, USA

by intric8 posted Thu Oct 04, 2018 7:19 pm

@nonarkitten:
Here you go!
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nonarkitten

by nonarkitten posted Thu Oct 04, 2018 7:40 pm

2019 is going to be a great year for Amiga.
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A10001986

by A10001986 posted Thu Oct 04, 2018 10:48 pm

That's great, as 2019 won't be the year of the Linux Desktop after all... :)
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intric8
Seattle, WA, USA

by intric8 posted Wed Jan 30, 2019 10:11 pm

I found and acquired a 2nd Rejuvenator but haven't been able to get it to work. The idea was if it did work we'd pull the Pals to see if our new board worked using them (proving the new board is viable).

One of the team members is going to take a look at it next Wednesday to see if he can find the source of the issue. When we fix it, it will get shipped to the schematic designer to use as his testing base against his own new boards (we have half a dozen printed, and he's populating one right now).

Once we prove the new boards are good to go, which shouldn't take too long, we'll do the last part: decoding the Pals. And work has already begun with the calculations.

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