A500 chip ram upgrade?

[psxphill]

Keep in mind.... that if you perform the 2MB chip mod using a 2MB Agnus + MiniMega + Trap Door 512KB, that you will no longer have any Fast Ram.

There is a 2mb upgrade that allows you to still use the trap door. I know because I used to have a revision 5 a500 with 2mb chip, 1.5mb slow memory & 2mb fast ram. It was awesome, it could run anything.

I still have the hardware somewhere, but it's not assembled right now.

[psxphill]

Maybe you're thinking about an A500+?  A500+ is an odd animal. I should get one for the learning experience.

Bust that puppy out and post up!

No it was definitely an a500. It's all in pieces spread in boxes unfortunately.

I started with a 512k slow memory upgrade, then added a 1mb slow upgrade that had a pass through so you could have 1.5mb. Next came the 2mb chip ram upgrade, which also connected to gary. IIRC this was a unique one in that it contained 2mb of chip ram & didn't use the motherboard chip ram or the trapdoor slot ram. I don't remember if I knew it was different to the others when I bought it.

[psxphill]

The type of Ram in the trap door is called "Ranger" mem.
Not as fast as 'real' FastRam, but faster than CHIP Ram.

It is exactly the same speed as chip ram. It suffers from the same slow down if there is a lot of dma activity, which is the only reason that chip ram is slow in the first place.

The trap door isn't actually ranger memory, it just appears at the same address as the 512k extra ram in the ranger prototype and then the third party boards which were based upon it. I believe this was true fast ram.

The fat agnus was an anti amiga inc (los gatos) project. Jay claimed it wouldn't work and that ranger should be the next step, which likely encouraged the chip guys even more to make it work.