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Is there any reason I should NOT upgrade chip RAM to 2MB?

Posted: Mon Jan 07, 2019 2:41 pm
by oldbull
Now that I know my A500 functions, I'm writing up a first draft of a "wish list". It's a rev 6A with 8372A Agnus. I know I can get to 1MB chip ram with that Agnus.

BUT...

Those 4 empty chip spaces on the motherboard are in my thoughts. Before I take the time and money to track down 4 memory chips, a 2MB Agnus, and a 1MB trapdoor card, I need to know if having 2MB chip RAM will cause problems with any software.

Thank you.

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Mon Jan 07, 2019 3:08 pm
by intric8
In my opinion, adding Chip RAM is never going to hurt anything at all. Only if you start to upgrade your KS or upgrade some of the other custom chips to ECS could you potentially see compatibility issues with some software. That being said, before soldering RAM to your MB, it's worth keeping an eye out for a MegaChip upgrade, too.

It's a little board that presses into the Agnus socket, and a 2MB Agnus sits inside it. It looks like this:
megachip.jpg
I use one of these in my A2000 and it is flawless. Very easy to install as well (once you've torn the machine apart, that is).

So you'd only have to source the little board and the Super Fat Agnus, and they usually come together. There's one on Ebay right now, as a matter of fact.

In addition, adding an MKL 8MB (fast) RAM upgrade that lives right below the 68000 processor (and only costs ~$50) and you'd have a smokin' machine (smokin' in a good way).

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Mon Jan 07, 2019 4:22 pm
by EzdineG
As an alternative, a good friend of mine sells 2MB "megachip" boards for under $100 including Agnus on Amibay. The only real problem is that you'll have to physically desolder the Agnus socket and replace it with what you receive.

I've done a few of these, it really isn't a big deal if you're comfortable with a soldering iron. This board + 512k trap door = 2mb chip.

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Sat Jan 12, 2019 4:34 pm
by hlide
@EzdineG

I guess we have the same "good friend" as I bought the same product for $30 (without Agnus) because I already have a compatible Agnus. Because I also have an A3000 Agnus and a rev6.A board and the 2MB chips, I'm still pondering about which to choose.

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Sat Jan 12, 2019 11:14 pm
by EzdineG
hlide wrote:@EzdineG

I guess we have the same "good friend" as I bought the same product for $30 (without Agnus) because I already have a compatible Agnus. Because I also have an A3000 Agnus and a rev6.A board and the 2MB chips, I'm still pondering about which to choose.
The choice is easy. Use the A3K Agnus and the RAM chips you already have. The adapter you purchased from Viktor leaves the A500 without the ability to genlock. I don’t believe the A3K Agnus mod has this limitation.

Not that I’d ever be using that functionality, but if you have a choice...

[Edit] Using your A3K Agnus should also give you the ability to jumper between PAL/NTSC booting.

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Mon Jan 14, 2019 2:21 pm
by McTrinsic
Who uses a genlock?

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Mon Jan 14, 2019 2:24 pm
by intric8
@McTrinsic, I'm embarrassed to admit I have one en-route to me right now. It's the one made especially for the A1000, and fits into it like a glove: the Amiga 1300. I couldn't help myself. Made by Commodore Amiga for the 1000? Yes, please.

Will I ever use it? Hm. Not any time soon.

But check out all these cool features! :)
  • connects to the 23 pin RGB connector and slips under the A1000
  • allows overlaying Amiga graphics onto an incoming video signal
  • composite input and output (two RCA connectors)
  • two stereo audio inputs and one stereo output
  • audio mixer for the two inputs
  • horizontal position and hue adjustments
  • DB23 RGB passthrough connector

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Tue Jan 15, 2019 1:53 pm
by McTrinsic
No worries. I’d also love to have one as back then I would have loved to have it.

Point being - will you use it?

OK, the 1300 at least got an audio mixer :) .

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Wed Jan 16, 2019 5:14 am
by A10001986
Please define "use" with regard to Amiga hardware in general in 2019.

;)

Re: Is there any reason I should NOT upgrade chip RAM to 2MB

Posted: Wed Jan 16, 2019 1:17 pm
by oldbull
I thought of another way to approach my original question:

Are there any programs that have problems on Amigas with "greater than 512k" chip RAM?

I know the ACA500+ has a menu setting to allow remapping the trapdoor RAM. That seems like a safer way to go because I can enable/disable that setting and go down to 512k chip if needed. But will I ever need to go back down to 512k chip is the thing.