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)?

[zipper]

Without battery just default settings. With battery:
NVRAM
~~~~~
   The A3000 also has a NVRAM configuration which is powered by the
same battery which the clock is.  It supports the setup of the following:

   SCSI Controller ID:   This places the onboard SCSI controller
            at a specific ID location, 7 by default.
            You can change this to something else,
            to get a device at 7, but be careful
            of conflicting the SCSI controller and the
            device addresses.

   Long SCSI Timeout:   This slows the boot process for SCSI
            drives, for those units which take longer
            to spin up and be ready.
   
   Synchronous SCSI:   This enables Synchronous SCSI mode,
            which can speed access on some drives.
            This is fully operational on Kickstart 3.1.

   Multiple LUNs Mode:   This enables multiple LUN's, which allows
            for multiple drives at each address.

   These options can be toggled using various freeware programs
available on the Aminet file archive on the Internet.  SCSIPrefs
(Aminet:hard/drivr/SCSIPrefs.lha) is one of them, but there are many
others.  Some things to note: It's a better idea to get a Prefs program
that is simple, basic and doesn't use any OS extensions like MUI, as if
you accidentally set something wrong and your system doesn't boot, it'll
be easier to load your basic Prefs program than something which requires
all of MUI.  Why do I write this?  A friend did this and had to install a
base MUI setup, taking many extra hours.

[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.

[mechy]

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.

the A3000 will see the pcmcia slot,and it will work/BOOT with the pcmcia to cf adapter in that slot without any changes/battery because its lun0. other slots are luns 1-4 and will be ignored without LUN'S SET ON.

SYNCHRONOUS usually improves speed some.
its possible to call the scsi settings in the startup sequence but might likely need a reboot once.
A battery is best is easiest if you can replace it.

[TCMSLP]

I can't imagine having a 3000 without battery - do you set your clock via NTP?

I guess the best option is to fit a battery away from the main board,

[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.

[mechy]

it will boot fine with or without a battery,with the rare exception scsi vram is scrambled somehow,but i've only heard one case of this in 20 yrs.

If you dont mind a external card reader, what you can do is install it in a old external floppy case and build a scsi cable to hook to the back of the 3k scsi port. makes for a pretty slim external card reader solution.

@tcmslp Getting time from internet works very well on amigas with badly damaged boards that are not practicle to add a battery. Its more accurate than onboard time in alot of cases.
They draw very little power and run cool,so no worries the card reader will get too hot etc.

[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.

[QuikSanz]

Send it to Acill!

[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.

[mechy]

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.

yes it should be, call the scsi settings in startup-sequence or user-startup, but i think it will need a warm reboot and then it will be active(likely the 3.9 reboot will do it if you call it in the startup early enough).just add a line to enable luns.

http://aminet.net/package/driver/media/SCSIPrefs

or
http://aminet.net/search?query=setbatt

[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.

[mechy]

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.

sounds like it can't find the clock chip,so yes i suspect its bad or not repaired right. the chip holds the scsi settings ;/
you might also check voltage to the chip with the amiga powered.

chip is here if u need one,i think its the correct one: https://www.ebay.com/itm/RICOH-RP5C01-DIP18-REAL-TIME-CLOCK-WITH-INTERNAL-RAM/361790820669?epid=1223826694&hash=item543c69d13d:g:zBkAAOSwn7JYD4Um

you might also check voltage to the chip with the amiga powered.

Anthony Hoffman has a great tutorial on clock circuit repair:  http://amiga.serveftp.net/RTCrepair.html

[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...