Amiga 3000 Battery and SCSI NVRAM

[madgrizzle]

I read this about the Amiga 3000:

"The built in SCSI host adapter - based around the Western Digital 33C93 SCSI controller - supports up to seven devices connected simultaneously. The controller's configuration is stored in a NVRAM powered by the same battery which the clock is."

I pulled the battery out of my Amiga 3000 and, even though I have some issues with the SCSI drive not wanting to boot unless I pull the power cable out of the computer and reinsert it, I've not had to "reconfigure" the SCSI device.  

Is the battery needed in the A3000?

Does the PSU supply power even when turned off to keep things in memory (maybe why pulling the plug on the computer gets the SCSI drive to boot)?

[madgrizzle]

Without battery just default settings. With battery:
NVRAM
~~~~~
   Multiple LUNs Mode:   This enables multiple LUN's, which allows
            for multiple drives at each address.

Hmmm.. I have a mechware reader that uses LUNs that I was thinking about installing here.  So if it is disabled by default, sounds like I'll need a battery.

[madgrizzle]

Thanks mechy.. that's good to know.  I have a coin battery thingy coming and will solder it on.  I was wondering what to do if I needed to replace the coin battery (will it stop booting).. but as long as I boot from the PCMCIA, sounds like I'll be fine.

I haven't really used the 3000 yet, just got it working after 'fixing' the battery damage.  I'm waiting on KS3.1 to arrive before I move the mechware over from my 2000.. shame the front cover of the 3000 isn't 'configurable' like the 2000.  I'll have to figure out something with that.

[madgrizzle]

I put a coin battery into the amiga and I assume it's working as I don't need to boot from a floppy after it sits for a while.. HOWEVER, when I try to run SCSIPrefs, it reports:

Can't find battery backed up memory

If I run setbatt-1.2, it reports:

Failed to open "battmem.resource"!

I've got loadmodule battmem.resource in the startup-sequence so it's at least getting loaded.  Any suggestions?  This was a battery damaged A3000 that I got working again.  Where is the NVRAM located?

Update:  I cant click save when I try to set the time (ghosted) and when I reboot, the time is lost.  Maybe the battery isn't working.

Update: So it's U190 (RP5C01) that has the nvram it seems.  maybe something not entirely fixed.  sigh.

[madgrizzle]

Pretty confident he has a lot of backlogged work...

[madgrizzle]

While I'm trying to get the NVRAM to work, is it possible to enable LUNS support a different way?  I'm trying to run OS3.9 from a PCD-50B and REALLY want the SD card to work (which requires LUNS)... it's how I transfer files to the Amiga.

[madgrizzle]

Those programs won't run for me.. I get error messages about not being able to access the battery backedup RAM.  I think maybe my RTC isn't completely repaired.

[madgrizzle]

http://amiga.serveftp.net/RTCrepair.html[/url]

Very good resource, even though its for a 4000, I've been able to do some mental gymnastics to keep track of the tests.  However, I ran into something odd.

With the 3000 daughtercard installed, I get a good solid continuous continuity tone from the +5V feed to ground.  With the daughtercard removed, its only a chirp (which I associate with capacitors charging).  The daughtercard looks pristine and I don't readily see anything that would suggest a short.

Should there be 'continuity' between +5V and ground with the daughtercard installed?  This seems to me to be a bad thing to have...

[madgrizzle]

Anthony Hoffman has a great tutorial on clock circuit repair

Very good resource and even though its for a 4000, I've been able to do some mental gymnastics to keep track of the tests.  However, I ran into something odd.

With the 3000 daughtercard installed, I get a good solid continuous continuity tone from the +5V feed to ground.  With the daughtercard removed, its only a chirp (which I associate with capacitors charging).  The daughtercard looks pristine and I don't readily see anything that would suggest a short.

Should there be 'continuity' between +5V and ground with the daughtercard installed?  This seems to me to be a bad thing to have...