SupraDrive 500XP + Trapdoor ram problem

[dougal]

Yesterday I got an A500 which came with a SupraDrive 500XP and a 2MB trapdoor expansion.

With the trapdoor ram enabled the HDD does not boot or even be seen.

As soon as I disable the trapdoor you can hear the HDD working and it works perfectly.

The SupraDrive has 4MB ram inside it. That works correctly both with the trapdoor ram enabled and also disabled.

I also tried it in my A500+ which has a 1MB expansion (Total 2MB chipram) and had the same issue. Can see 2mb chip and 4mb fast but no HDD.

Disable the trapdoor ram and the HDD works.

I don't know if its worth noting but I do NOT have the optional PSU for the Supra.

Also worth noting that I am using the same PSU that I use for my A1200 which has a Blizzard 1230IV and HDD. Its an A500 heavy PSU, so it should be good enough.

[dougal]

The HDD spins up with the trapdoor expansion in, but it doesn't make the reading clicking sounds of the self test as it does when the trapdoor ram is disabled.

I don't have any spare SCSI drives to test.

As far as I've read on Amigaresource the power supply for the supradrive is optional but on the manual it states that it is included. So conflict there.

In any case I don't have an external power brick for it unless I can use the same one of the CD32 or A590.