Topic: Replacing Archimedes A300 Battery - Help required  (Read 4143 times)

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Offline Panther

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Replacing Archimedes A300 Battery - Help required
« on: September 01, 2011, 01:56:35 PM »
Well not so much help in replacing the battery, more as to what diode to use and where to obtain it from.

Confused yet ? if so I shall explain

I have my A3000 that appears to have a faulty battery as when I power on it loses all of it's settings (including the internal HDD info), I replaced the battery but still no luck and it has therefore been suggested that perhaps the internal charging circuit is FUBAR'd.

After doing some digging around I found this excellent walkthrough on how to strip an A3000, change the battery and rebuild

http://www.waitingforfriday.com/index.php/Restoring_an_Acorn_A3000_computer

The author describes how he changed the standard internal battery for a 1.5v 'AA' but soldered in a diode to ensure that this doesn't get charged. Whilst this may not be an issue I want to err on the side of caution. However what diode do I require and where do I obtain one from ? Is there anything suitable on a speccy mobo as I have a few duff ones of these lying around.

Help appreciated as always

Offline Phu

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #1 on: September 01, 2011, 02:19:02 PM »
The diodes on a speccy are 1N4148 signal diodes are not suited for power circuits. There is also the zener diode used for the -5V circuit, but thats even worse because it conducts in both directions if you put enough oomph in!

What you want is 1N4001. These are quite common, particularly in rectifier circuits. If you got an old speccy PSU, there's four inside there.

Otherwise, Maplin will have these for around 2p a piece.

-- Richard
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Offline Prime

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #2 on: September 01, 2011, 03:16:01 PM »
What you want is 1N4001. These are quite common, particularly in rectifier circuits. If you got an old speccy PSU, there's four inside there.

Otherwise, Maplin will have these for around 2p a piece.

Well not quite that cheap but 29p, which is supprisingly cheap for Maplin.

Cheers.

Phill.

Offline Panther

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #3 on: September 01, 2011, 03:57:03 PM »
Cheers,

I'll take a look the weekend  :) need to get this sorted, fed up of keep typing in the HDD commands at boot up !!


Offline Phu

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #4 on: September 01, 2011, 03:59:36 PM »
What you want is 1N4001. These are quite common, particularly in rectifier circuits. If you got an old speccy PSU, there's four inside there.

Otherwise, Maplin will have these for around 2p a piece.

Well not quite that cheap but 29p, which is supprisingly cheap for Maplin.

*cough*ripoff*cough*

http://uk.farnell.com/diodes-inc/1n4001-t/diode-rectifier-50v-1a-do-41/dp/1843694

-- Richard
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Offline Panther

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #5 on: September 01, 2011, 04:11:37 PM »
£0.033 !!!!

Bloody hell, second mortgage required !!  :)

Offline Prime

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #6 on: September 02, 2011, 01:28:13 AM »
Well not quite that cheap but 29p, which is supprisingly cheap for Maplin.

*cough*ripoff*cough*

http://uk.farnell.com/diodes-inc/1n4001-t/diode-rectifier-50v-1a-do-41/dp/1843694

Indeed, if you are also ordering other stuff from Farnell, as they have a £20 minimum order, Maplin has the distinct advantage that if you want one today and live near a store and they have one in you can get it. Of course if you want to buy more than a couple then I agree Farnell, Rapid etc are cheaper.

Cheers.

Phill.

Offline Panther

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #7 on: September 05, 2011, 12:44:12 PM »
New diode has now been purchased from Maplin for the extortionate fee of 29p !! Will see how that goes.

Offline Panther

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #8 on: September 12, 2011, 04:48:39 PM »
Carried the mod out yesterday, will see tonight if it's managed to remember it has an hard drive fitted (well CF card)

Is there anyway to clone an Arc HDD on a PC ? or do I have to reload everything back onto it ?

Offline Phu

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #9 on: September 12, 2011, 05:25:07 PM »
Sort of...

If you download and burn a linux live cd and boot it (you don't need to install it, it just gives you access to certain tools that would be a pain in the arse in Windows*) then you can use dd to clone the raw disk, e.g.:

dd if=/dev/sda1 of=/mountpoint/of/your/windows/partition/disk.img

You can then write this back to a new disk by reversing if and of. Of course, a lilttle linux/dd knowledge would help.

You may need to ensure the new disk is *Excatly* the same size (i.e. to the byte) as the old one.

-- Richard

* Most windows imaging tools assume a windows filesystem. When they encounter ADFS with its 256-byte sectors they shit themselves and refuse to cooperate.
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Offline Panther

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #10 on: September 12, 2011, 07:24:21 PM »
Well I think I'll just  start from scratch again then  :) I've already formatted a few 800K disks on the Arc ready to accept some stuff  ;D

Good news is that I turned the A3000 on tonight (not been powered on for 24hrs) and it booted straight to the desktop and showed the harddrive ;D

Got a game on a single disk to bring Saturday (unless it's already on the RCM Arc), game called Chaos, pretty decent version of Asteroids  :)

Also it now houses a 1Gb CF card in place of the 128Mb one I had, so plenty of space for games  :)

Offline Prime

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #11 on: September 12, 2011, 09:41:39 PM »
Sort of...

If you download and burn a linux live cd and boot it (you don't need to install it, it just gives you access to certain tools that would be a pain in the arse in Windows*) then you can use dd to clone the raw disk, e.g.:

dd if=/dev/sda1 of=/mountpoint/of/your/windows/partition/disk.img

Just a word of caution, if you are not familliar with Linux it would be best to disconnect your main drive and go directly old Archemedes disk to new Archemedes disk rather than via an image file.
Reason is get the of=blah device wrong and you just overwrote your windows drive with however many megs of arc data :( :(

Note unlike windows for the most part Linux and Unix based operating systems assume that if you type a command that's what you want it to do even if it is potentially destructive !

Cheers.

Phill.

Offline IanS

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #12 on: September 12, 2011, 10:03:01 PM »
Got a game on a single disk to bring Saturday (unless it's already on the RCM Arc), game called Chaos, pretty decent version of Asteroids  :)
http://www.spheresofchaos.com/ ??

Spent many an hour playing that.

Offline Panther

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Re: Replacing Archimedes A300 Battery - Help required
« Reply #13 on: September 12, 2011, 11:31:50 PM »
That looks like the one  ;D