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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: curtis on December 20, 2012, 11:33:54 PM

Title: MegaChip in an A500+
Post by: curtis on December 20, 2012, 11:33:54 PM: Picked up a 500+ mobo a couple of weeks back and was wondering IF a megaChip board could be added to it and if so, what would the memory configuration look like?

The motherboard has 1Mb onboard.

Thanks,

Curtis
Title: Re: MegaChip in an A500+
Post by: Lurch on December 21, 2012, 12:55:28 AM: Quote from: curtis;719846
Picked up a 500+ mobo a couple of weeks back and was wondering IF a megaChip board could be added to it and if so, what would the memory configuration look like?

Not needed/wont work, just buy a 1MB trap door expansion for the A500plus.
Title: Re: MegaChip in an A500+
Post by: Jope on December 21, 2012, 07:46:03 AM: Indeed it will not work. The Agnus socket has a different pinout in the A500+.
Title: Re: MegaChip in an A500+
Post by: curtis on December 21, 2012, 11:42:24 PM: I was pretty sure it wouldn't work, but wanted to make sure.

Now the hard part, find a 1Mb trapdoor expansion!
Title: Re: MegaChip in an A500+
Post by: Lurch on December 22, 2012, 07:12:28 AM: airey36 to the rescure :-)

http://www.ebay.co.uk/itm/amiga-502-500plus-1-Meg-ram-upgrade-board-tested-Good-Condition-/121041031851?pt=UK_VintageComputing_RL&hash=item1c2e9b92ab

http://www.ebay.co.uk/itm/amiga-500plus-502-1-Meg-ram-upgrade-board-tested-Good-Condition-/310541439352?pt=UK_VintageComputing_RL&hash=item484db65178

http://www.ebay.co.uk/itm/amiga-Marpit-Developments-500plus-1-Meg-ram-upgrade-board-tested-Good-Condition-/310537301470?pt=UK_VintageComputing_RL&hash=item484d772dde
Title: Re: MegaChip in an A500+
Post by: Darth_X on December 22, 2012, 09:43:11 AM: Quote from: Jope;719875
Indeed it will not work. The Agnus socket has a different pinout in the A500+.

Is it a 2MB Agnus on the A500+?
Title: Re: MegaChip in an A500+
Post by: Lurch on December 22, 2012, 10:06:21 AM: Quote from: Darth_X;719991
Is it a 2MB Agnus on the A500+?

Yes.
Title: Re: MegaChip in an A500+
Post by: desantii on December 22, 2012, 01:53:44 PM: You can also use a regular a 500 512kn expansion for now and have 1.5mb chip ram

Quote from: curtis;719948
I was pretty sure it wouldn't work, but wanted to make sure.

Now the hard part, find a 1Mb trapdoor expansion!
Title: Re: MegaChip in an A500+
Post by: curtis on December 23, 2012, 12:26:16 AM: Thought that would be the case, but with airey36 having 3 of them available at a reasonable price, I think I'll go that route.

Thanks everybody for the input and especially Lurch for the links!

Curtis

Quote from: desantii;720006
You can also use a regular a 500 512kn expansion for now and have 1.5mb chip ram
Title: Re: MegaChip in an A500+
Post by: Lurch on December 23, 2012, 07:26:23 AM: Glad I could help, hopefully shipping wont be too bad. airey is pretty good and I usually get stuff I've ordered pretty quick and I'm on the other side of the planet :-)

Hard to beat his pricing though.
Title: Re: MegaChip in an A500+
Post by: Oldsmobile_Mike on December 25, 2012, 02:51:53 AM: What would happen if you stuck a 1meg board designed for the A500+ in a regular A500? How much of it would be recognized, i.e., as "slow-fast" memory?
Title: Re: MegaChip in an A500+
Post by: Zac67 on December 25, 2012, 01:41:15 PM: Quote from: Oldsmobile_Mike;720257
What would happen if you stuck a 1meg board designed for the A500+ in a regular A500? How much of it would be recognized, i.e., as "slow-fast" memory?

512K (which may possibly not work, or nothing at all)
Title: Re: MegaChip in an A500+
Post by: Lurch on December 25, 2012, 08:17:33 PM: 512k... works just fine but wont go over 1MB as is expected :-)