Getting to grips with a Rock Lobster.

r0jaws

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I picked up a really nice clean example of an a500+ at a car boot sale today for a tenner.
I have to say I was really impressed with how carefully this machine was looked after by it's previous owner. It took him 10 minutes to pack it up for me after I handed over my crisp £10!
Whilst not being "mint" it is very clean and white, much more so than you can usually expect from this age of machine.

a5000.jpg


I also noticed that it had what appeared to be a ROM switch mounted on the side, a very neat little mod which will prove useful.

a5001.jpg


First things first lets check out this baby and make sure she works,

1.3 ROM boot screen
a5009.jpg


2.04 ROM boot screen
a50010.jpg


That's all good then. :D

Stripping off her creamy top, got to check that battery!
a5003.jpg


Not a speck of dust, how very weird,
a5005.jpg


ROM switcher, too cool for school,
a5006.jpg


Rock Lobster! :drinkin:
a5008.jpg


Oh Noes! Battery leakage!
a5007.jpg


Underside of battery area, this needs to be sorted fairly quickly,
a50013.jpg


Out, and ready for a visit from Dr Solder, ably assisted by Nurse Flux.
a50015.jpg


Now, I'm no soldering genius, but I'm fairly sure that if solder refuses to budge when exposed to temps of 480 deg C that this is going to be one tricky little job.
I slathered the flux on like butter on a crumpet but, to no avail. I've just ordered some wick that may help draw it out.
Dang, but I love a challenge. :wink:
 

Zetr0

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Re: Getting to grips with a Rock Lobster.

AWESOME!!!

Now I can give you that CBM A501+ 512KB Chip upgrade!!!! its yours =D

AND NOW you have a use for that 8MB upgrade too =D *sweet!*

Now all you need is IDE or SCSI and your rollin' =D

------

That battery is going to be a stubborn B to the I to the T, C and H m8.. the whole battery assembly will act like a heat sink...

use a small pair of snips to snip the battery free, run you iron to around 430 (as you dont have a digital 5/6ths the way round )

*give the iron an extra minute or two to catch up.... while doing so lay down flux on BOTH sides =)

now from the TOP of the board, add the heat from the iron and (not burning your fingers) pull the legs free once the solder has melted...

Now, remember to CLEAN well =D

looking forward to the pics my friend :)
 

Firthy2002

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Re: Getting to grips with a Rock Lobster.

I miss my A500+.

Damn that's one nasty looking battery! Hope you can get it out!
 

Harrison

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Re: Getting to grips with a Rock Lobster.

That reminds me to strip my A500+ down and check the battery too.

BTW, is anything else needs if converting to a coin style battery holder? Any extra things like resisters needed?
 

Nathanieltolbert

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Re: Getting to grips with a Rock Lobster.

Wait a minute, the motherboard in my A500 states that it's a rock lobster, but my board doesn't say it's an A500+. Were there several revisions of the same board with the same name?
 

rkauer

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Re: Getting to grips with a Rock Lobster.

Harrison said:
That reminds me to strip my A500+ down and check the battery too.

BTW, is anything else needs if converting to a coin style battery holder? Any extra things like resisters needed?

No resistor, just a diode. Prefer a 1N60 (germanium unit) as they have a lesser voltage drop. Search for lithium hack on Aminet.

Nathanieltolbert said:
Wait a minute, the motherboard in my A500 states that it's a rock lobster, but my board doesn't say it's an A500+. Were there several revisions of the same board with the same name?

All A500 units are "Rock Lobster", don't matter the board revision or features.
 

r0jaws

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Re: Getting to grips with a Rock Lobster.

Cheers for the inputs guys.
I've spent most of my evening wrestling with this battery. It certainly was a Biatch! :boxer:

Got the snips on it and removed the battery body itself, if nothing else removing the reservoir of contamination.

a500Batteryremoval0.jpg


That was the easiest bit! By far and away the hardest part was removing the single pin connection closest to the chip. With the corrosion, a snug fitting leg and some brutally stubborn solder it took nearly 2 hours to get the last of that out, I even used the Hot Air with some success, although I had to be very careful so as not to scorch the PCB!

I spent another half hour cleaning up all the flux with screen wash and then mopping up and finally drying off with a hair dryer.
I did a couple of continuity checks on some of the traces that had been blackened, and looked damaged and everyone checked out A Ok. :thumbsup2:

a500Batteryremoval1.jpg


a500Batteryremoval2.jpg


I'm really quite chuffed TBH, this is the first time I've done any sort of desoldering work Solo, especially to rescue an ailing board. It was hard work, but the fact that it's done and it all works is a great feeling. One more Miggy saved from battery death!

a500Batteryremoval3.jpg
 

Kin Hell

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Re: Getting to grips with a Rock Lobster.

OMG! That's an awesome repair job. Nice one Phil. I am seriously impressed. Well done m8y. :D

Charlie

PS. One of my favourite games on sceen too. :mrgreen:
 

Zetr0

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Re: Getting to grips with a Rock Lobster.

Great work r0jaws! (y) (y)

I dont know what to say... i dont want to sound condesending but I am rather pleased to see your first bit of unsupervised work... you have a latent talent... =D

This certainly was no mean feat my friend,

you had a huge battery acting like a giant heatsink, when you look at the bottom of the board you also have a HUGE ground plane, that again, acts as a giant heatsink!

you managed to remove the battery and keep the through-hole ringlets!... thats something to be chuffed at!

well done indeed m8y!

in the spirit of another sensi game... "you have advanced a tech level!"
 

r0jaws

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Re: Getting to grips with a Rock Lobster.

Thanks guys, I appreciate the comments. (y)

If it hadn't been for the patient tutelage of Zetro, the Flux Mastah, this padawan would probably have set fire to the board, table, my own eyebrows etc. :bowdown:

That Ground was difficult, which is why I thought about using the hot air (eventually).That got the solder moving. If I used the iron, nothing happened at all. I may as well have tried to chip it out!
 

keropi

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Re: Getting to grips with a Rock Lobster.

nice job r0jaws !!!! Another amiga rescued! :thumbsup2:
 

r0jaws

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Re: Getting to grips with a Rock Lobster.

The Rock Lobster goes from strength to strength.

Received an AlfaData Alfa Power Expansion from Rudi. For those who don't know what it is, it provides upto 8Mb Fast RAM and access to IDE ports.

What makes it a bit special is that it has both a 40 AND 44 pin IDE connector with internal power supply available. This means that it can have an IDE hard drive and CD ROM hooked up simultaneously.
It can also be powered entirely by the 500, but also has a power brick for hungry hard discs, or for when you have a CDROM attached.
I have fitted this with a 4Gb CF Card with WB 2.05 installed, and it does not require the power brick as well, leaving you with a less cluttered desktop.

It also has switches on the front enable you to switch the RAM or Hard Disc on and off as you wish.

a500Alfadata0-1.jpg


a500Alfadata1.jpg


a500Alfadata2.jpg


The only problem I have, is that I miss identified my ROMs as 2.05, I only have a 2.04 ROM! Unfortunately, that doesn't have the patch enabling it to boot from IDE. Bah! :Doh:

However, once I get these installed, and maybe even get hold of some patched 1.3 ROMs, I'm sure she will be good to go. (y)
 

Zetr0

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Re: Getting to grips with a Rock Lobster.

ROMS you say ;)

Looking great r0jaws!!!!
 

rkauer

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Re: Getting to grips with a Rock Lobster.

Not a problem if the A500+ have just 2.04 ROM, Phil.

The device will boot straight away with the 2.xx ROM, but not with 1.3 without some little hack or with a slightly modified 1.3 ROM.

Just to remember the old times, all you need to do is setting a 1.3 partition using the tool from the A2091 install and then save changes to the RDB. This will make the first partition bootable (don't forget to put a copy of the AlfaData SCSI/IDE device into the EXPANSION drawer!). After that, all partitions you want to be available to the 1.3 ROM must be mount-listed. Pretty much the same for 2.1, IIRC. But 2.xx just need the wanted at-boot partitions saved to the RDB.

Have a lot of fun with this piece of retr0-licious hardware history. (y)
 

Kin Hell

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Re: Getting to grips with a Rock Lobster.

Nice one r0jaws. (y)

Kin
 

chiark

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I think an A500 or 500+ with KS1.3 will boot the alfapower without any problems at all... Apologies if I'm missing your point here rkauer :)

I don't think you need the stuff in the expansion drawer either, as the driver is loaded at boot from the autoboot roms...

(I know we're not talking about gayle emulation devices which would need 2.05 or a 1.3 with scsi.device embedded here :D )
 

rkauer

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You remember the old-school days? At least the RDB must have the (auto boot and necessary at boot time) partitions and file systems saved into for proper operation.

Other partitions and devices can be invoked by mount list.

But as I remember, the device driver must be tossed inside the expansion drawer even for those who have the ROM in memory (or was it from kick 1.2 time?). My memory fails on this...
 

chiark

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I do remember the old days :D . I stil live 'em :D . This is my experience/memory: I could be wrong...

A lot of controllers from the old days didn't support RDB so had to have a single partition with particular geometry or used a non-standard RDB-style approach which only mounted 1 partition. The Spirit HDA-506 is like this.

If the controller supports RDB, I believe it should mount everything under 1.3. I think. Certainly the SupraDrive mounts 3 partitions under 1.3 without an apparent mountlist... I'll give this another check to see what exactly is happening :D

The device driver is needed in the Expansion drawer is for 1.2 boot disks for hard drives, or for other devices which don't have enough space to load their drivers (such as bridgeboards, which do need the right driver in expansion).

I could be horribly wrong!
 

AndyLandy

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If you need a Kickstart 2.05 ROM, I can send you a 37.300 for the cost of postage. Alternatively, you have enough FastRAM that you could put Kickstart 3.1 in there and install Workbench 3.5/3.9

Actually, I might even have a spare 2MB ChipRAM expansion for the A500+ lying around somewhere if you are interested.
 
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