Ongoing A4000 saga.....

[Jose]

Ok, now that the PSU is working I think I'll just name this thread like this cause there will probably be a heap of problems to resolve...

Right now:

Nothing happends. Just a grey screen.
I'm using a 3640 board rev.3.1 and a 4MB SIMM on the Chip RAM slot.

I've also set J100(CLK 90 Clock Source)to external and J104 (CPU Clock Source) to internal... can someone confirm?
Saw this on amiga-hardware.com
I've also tried with a different SIMM but the result was the same. Is it picky with mem modules?

Slowly I'll get there 8-)

[Jose]

And I've currently the HD and floppy disconnected, but I think the tick screen should appear anyway...
I'm using 3.0 Rom, so wait time shouldn't be that long...

[Ilwrath]

First off:

Warren Block's A4000 reference page <-- The single best A4000 resource I've found.

I've also set J100(CLK 90 Clock Source)to external and J104 (CPU Clock Source) to internal... can someone confirm?

I believe both J100 and J104 should be set to external.  (AFAIK Both clocks come from the 3640 card, but I haven't found a site to confirm this.)

I've also tried with a different SIMM but the result was the same. Is it picky with mem modules?

Yes, it's very picky.  But if you get it wrong, it'll usually either mis-detect the chip mem size, guru, or cause a green-screen fault.

[Castellen]

Correct, with the A3640 both clock source jumpers need to be set to external.
It won't have done any damage by getting them wrong, the computer just won't run.

[Jose]

Yes!!! :-D  Got the Rom screen when I set both jumpers to external.
Now connecting the drives...

[Jose]

Why is it that I only get 1MB chip ram? :-o

By they way, I remember the A4000T needed a different workbench disk set tailed for it, cause it had SCSI2 drivers in the Rom and because of lack of space some stuff was loaded directly from the Workbench disks like workbench.library...
But is the A4000D workbench disk set the same as the A1200's ? I know the Rom's are diferent (different IDE drivers, due to different addresses or something..)...

[Ilwrath]

Why is it that I only get 1MB chip ram?

Wrong SIMM in your CHIP RAM slot.  Like I said, it's picky.  If you get one it doesn't like, it'll detect wrong sizing.  You really need to get a 2MB one of identical stats to the original.

But is the A4000D workbench disk set the same as the A1200's ?

Yes, I believe so.  Back in the day, I used the disk set from my A1200 to format and install my brand new (used) A4000D for the very first time.  :-)  I don't remember running into any problems.  

Also, AFAIK, you can use the A4000T disk set on any Amiga, it'll just copy a couple files you don't need.  (You just can't use any disk set other than the proper one on an A4000T, though.)

[Jose]

Hey8-)
Can someone confirm the configuration to use 8MB Simms?
I'm using bank 0 and 2 but still get only 4MB recognized.. Maybe it's the Simm? Still I'd like someone to confirm the configuration so that I don't have to try varous ones everytime I manage to get a borrowed one from a computer store to try out 8-)

 I also managed to get 2Mb chip ram with a 2MB Simm but the SIMM didn't fit well in the socket, and in the process of trying to fit it I forced it too much and hear a snap kind of noise.. Luckily everything is still fine, but I'm gonna try to get one that fits well and will never force it again!...

[TjLaZer]

@Jose

I use two 8MB SIMMs in my 4000.  Use the 2nd and 4th slot for the SIMMs. They work fine but the problem is they do not snap in as they are double sided, so they may work loose and fail so be aware of that.  Other than that it works fine.

[Jose]

Thx:-D , I'll try that..  Yeah, i got a green screen sometimes when I was using one that didn't snap.

[Hyperspeed]

A green screen is caused by something wrong with the ChipRAM or Agnus.
I didn't know the A4000t's ChipRAM was on a SIMM?

So this fabled 8mb ChipRAM jumper was almost there in terms of
reality!

:-o :-o

A grey screen confirms the CPU has passed.

:-)

I reccomend everyone use single-sided FPM no matter what Amiga. Why
use somthing that is fatter (double-sided) or has no performance
increase (EDO) on Amiga?

The lowest common denominator will always be FPM and it will always be
the most reliable.

You can also swap FPM with other Amiga users or sell it on when you
have upgraded to a larger SIMM.

If indeed the ChipRAM comes on a SIMM then I wouldn't dare change it
for something other than the Commodore original since there are so
many factors to take into account.

i.e physical size, speed, refresh, type, parity/ecc, contacts,
manufacturer

:-)