A4000 64mb motherboard mod and Warp Engine

[trixster]

That’s a good question. I didn’t actually try removing the mediator busboard or logic board and the reason for that is I am unwilling to sacrifice my mediator setup just to swap a WE for a CSMK2. So whilst the mediator might have been the culprit, knowing so wouldn’t have helped me get the WE up and running in my A4000.

It’s a loose end but I’m happy enough having the WE in the 3000 and keeping the CSMK2 in the 4000. I might strip the 4000 down someday and try the WE again ... but tbh when it comes to Amigas I’m moving towards “if it isn’t broken don’t try and fix it”. A working mediator system is a fickle beast, sometimes you just have to leave it well alone

[eteP]

I was just wondering if there was a more general problem with the combination WE + Mediator as I also have this setup and don't seem to get any PCI cards working. However, I've tested my setup with an A3640 in the meantime but still no luck with the Mediator...

[trixster]

Thread revival. After a year this is now fixed

I tried the WE again in my 4000, this time with 3.1.4 roms as I wondered if makeshift 3.1 roms with the fpu fix were somehow the problem. This didn’t change anything. So I inspected the WE again - all pins on J2 open with the exception of the far left hand one “L”. The manual says L is Reserved and all indications on the internet say to leave it closed; indeed, with it closed as normal the board works fine in my 3000 and AA3000+

Anyway, this is not so with this 4000! Opening jumper L and hey-pesto it now works fine!

So, any ideas why this jumper affects my 4000? Some clash with the 64mb mod, or the mediator?

[trixster]

Update: not 100% fixed - only 50% of the ram is seen. This is a modded WE now with 2 slanted simm sockets to fit in a 3000. In the 4000 with L removed only one of the 32mb Simms is seen by the 4000, so only 32mb shows up

[Wrangler]

@trixster As you know, I have had a similar problem: Warp Engine in an A4000d (with a Mediator) that goes into an infinite yellow screen reboot cycle. This A4000d and WE are unmodded (except the WE has an 060 in it). The only solution I've found is your trick of removing the L jumper (despite this being RESERVED) and then it works fine.

I think you are losing half your WE mem because you have had alternate slots on the WE removed and the ram configuration isn't finding the second bank of 32 MB. I'm seeing all the 128MB on mine.

But I still don't know WHY the L jumper fixes the problem or why the problem of the yellow screen occurs at all.

[trixster]

Yep, agree with you on the simm mod!

[trixster]

Next update: using addmem E000000 FFFFFFF Pri 40 I can add in the ‘missing’ 32MB. So the autoconfig of the memory was missing the 2nd simm.

[jaesonk]

Interesting reading.

Any more information about the reserved jumper?

I skimmed thru the documentation a few times and didn't see whether or not to set the A4000 motherboard jumpers to EXT or INT. I presume EXT. But the link provided in an earlier message says:
If you have an early Amiga 4000 that has a processor module with a 28MHz oscillator in U104, change the jumpers at JP100 and JP104 from "INternal Clock" to "External Clock".

Is it possible to update a WarpEngine to use use 64mb or 128mb SIMMs? 2x64MB or a single 128MB on a 3040 would max it to 128MB. Mine is the WE4040. Since the A4000 CPU slot can 256MB max on a turbo card, 4x64MB or 2x128MB SIMMs would hit that ceiling.

Should one be inclined to experiment with speed? What type of crystals are used on the WarpEngines? What vendor carries them?