My Amiga 2000 restoration

[Avrovulcan]

Part 1

Retrieved my Commodore Amiga A2000 from my mum and dad’s loft last week.
The machine could be about 32 years old (going by the dates on some of the chips). I purchased it whilst I was in the Royal Navy back in early 1991 from a computer shop in Plymouth called Computerbase. This shop is still there and over the years has supplied me with a few computers, normally being custom built high end PC compatibles.
This machine was mothballed some time in 1995 when I bought my first PC and hasn’t been powered up for at least 25 years. You’ll have to excuse the photos as they have been taken on my phone.



Here’s a picture of the inside of the machine. (this was taken after I had removed the Hard drive from the controller card).



From the left side of the machine the cards are: Commodore A2088 XT Bridgeboard, Supra Corp 8MB RAM expansion, GVP Impact II SCSI controller card, GVP 25MHz 68030 accelerator and on the far right a Microway Flicker Fixer. The small board on top of DF1 is a dual 1.3/2.0 ROM switcher. Out of sight under the floppy drive chassis is a ICD ADSPEED 68000 CPU and a ECS Agnus chip to give the machine 2MB of chip memory if I remember rightly. The main motherboard is a revision 4.4

The first thing I had to do was remove the Varta battery. This was the main reason I retrieved the computer. As we all know its not a case of ‘If’ these batteries leak but ‘when’.
After removing the floppy drive chassis I found that the battery had indeed leaked:



On closer inspection it seems I have got away quite lightly as regards the damage, which seems to have only attacked the solder mask and some corrosion to the legs of resistor R914. So I cut away the battery and gently scrubbed the area with a toothbrush soaked in a little vinegar to neutralise the juice from the battery. This area was then washed with a little soapy water and left to dry.



The area doesn’t look to bad. I have a brand new replacement battery and I’ll address the solder mask later on. I checked the electrolytic's on the power supply and motherboard/daughterboards for any signs of leakage or bulging and all seemed ok. I am not someone who believes changing electrolytic capacitors or any capacitor for the sake of it, unless the capacitors are of the Rifa brand, and then only if they are being use as mains input filters, or unless the capacitors do show signs of leaking/bulging. Its personnel choice really, its something I’m not prepared to waste my time on.

If I remember rightly the machine was set up to autoboot Workbench from the SCSI dirve. Now considering that the machine had been dormant for at least 25 years I didn’t hold up much hope that the hard drive wouldactually spin up and function.
So I plugged in the mains leads, connected a monitor and powered up the system. After about 60 seconds of the hard drive light flashing on and off the machine powered up to the 'Insert Workbench disk' prompt. Which is both good and bad. Good because this at least tells me that the RAM, ROM and graphics should be ok.
Bad because as I suspected the hard disk showed no signs of life. Well, as we all know, on any computer that has laid dormant for over two decades hard drives either don't work, or fail fairly soon after. If the machine had been power cycled regularly, even once or twice a year, the hard drive would probably still be ok. Pity really as I was keen to see what I had on it.
Any case, I found my old Workbench 1.3 operating system disk and after several tries I managed to boot to the workbench
It took a few attempts to boot to the operating system from disk as the runners and bearings on the floppy drives need lubrication.



So I have a working computer of sorts. I went to my local hardware store and purchased a can of White Lithium Grease so I can strip the floppy drives and lubricate everything. Next I’ll replace the clock battery. I have also ordered a 170GB SCSI hard drive off eBay, and that should be here next week

More soon


Kind Regards
Andy

[alexh]

Nice post. Looking good. What's next for you? A replacement hard drive? SCSI2SD v5 might be worth looking at. OS/KS 3.1.4? RTG Graphics Card?

Supra Corp 8MB RAM expansion, GVP Impact II SCSI controller card, GVP 25MHz 68030 accelerator

Do those three play nicely together? I would have thought the memory maps of those three would overlap.

ICD ADSPEED 68000 CPU

I'm surprised you're using this considering you've got a GVP 68030. I guess it was more trouble to take out than leave in.

ECS Agnus chip to give the machine 2MB of chip memory

You must have a MegAChip or similar to get 2MB.

[Jope]

Judging by the pics, the Series II doesn't have any RAM populated.

[amigasith]

Nice read and pics

Regarding the hard drive: I have successfully re-animated a couple of old hard drives by giving them a gentle knock from the side with a small hammer. This helps when the mechanical parts (heads or drive motor) are stuck, which happens quite often when the drives haven't been spun up for years.

[Avrovulcan]

Originally Posted by alexh

Nice post. Looking good. What's next for you? A replacement hard drive? SCSI2SD v5 might be worth looking at. OS/KS 3.1.4? RTG Graphics Card?

Hi. and thanks
To answer your questions, the replacement hard drive is on order. The one I had was a Quantum Fireball 101MB. I'm replacing it with a 170MB Seagate ST2209N. Ive seen the SCSI2SD system. This is plan B if I can't get the hard drive working. Although I would probably still one of these sooner rather than later. I've seen the V5.1 for quite a good price. As regards the O/S I'm open to anything once I get the system up and running. I have a copy of Circuit Studio, I like the idea of having a ROM switcher with more capacity, so adding one or more O/S upgrades would be defiantly on the cards once I knock up a Swittcher PCB with more than two sockets. As for the RTG graphics card, I've seen this and again it's something I'll get once I have the system sorted out.

Originally Posted by alexh

Do those three play nicely together? I would have thought the memory maps of those three would overlap.

TBH I don't ever remember having a problem. I don't remember any obvious issues. The ICD ADSPEED is disabled by the accelerator card I think. So it's sat there basically doing nothing.

Originally Posted by alexh

I'm surprised you're using this considering you've got a GVP 68030. I guess it was more trouble to take out than leave in.

I think at the time I couldn't afford the memory modules, which is why I ran both, although there would have been a speed penalty in the 030 addressing the 16-bit memory. That's assuming it could. I got the GVP Impact II and the Supra Corp card long before I got the Accelerator. Once I get everything sorted I probably will buy the correct memory modules for the accelerator and remove the Supra Corp RAM card.

Originally Posted by alexh

You must have a MegAChip or similar to get 2MB.

Aye, that's der bunny. I couldn't for the life of me think of what it was called.


Regards

Andy

[Avrovulcan]

Originally Posted by Jope

Judging by the pics, the Series II doesn't have any RAM populated.

That's correct the memory slots in the Impact II and Geforce 030 card are unpopulated.

Regards
Andy

[alexh]

GVP 25MHz 68030 accelerator

Which version is this? I can't tell from the photos. GeForce 030 Series 2?

http://amiga.resource.cx/exp/gforce2030

I think there are 3 or 4 GVP 030 cards each with different capabilities.

http://amiga.resource.cx/dir/a2000proc

If you find out which we can advise you how to upgrade this card. It should have an integrated IDE or SCSI controller depending on which model it is making the other SCSI controller unnecessary.

And RAM slots or a RAM card connector. Someone is (or was) remaking GVP SIMMs just recently which fit the SIMM slots on later models so you should be able to max it out for not a lot. Not so sure about the RAM boards for earlier models.

Earlier versions (A3001) have IDE but you may need the IDE ROM to make it functional, it should be easy to find and an IDE controller would allow the use of a cheap IDE->CF adapter.

If upgrade-able you could consider removing the other two cards (Supra Corp 8MB RAM expansion, GVP Impact II SCSI controller card) as they won't be needed. And they could raise money to pay for your upgrades if you considered selling them. The GVP Impact II HD8+ is/was highly prised.

I knock up a Switcher PCB with more than two sockets.

There are much more capable flash based cards available cheap today. I dunno if they support bigger ROMs (larger than 512K) on the B2000

NOTE: A GeForce 030 Series 2 supports MAPROM so you can switch in software without a kickstart switcher. Unlikely it can do 1MB but it might be able to do 512k (KS3.1)

[Avrovulcan]

Originally Posted by amigasith

Nice read and pics

Regarding the hard drive: I have successfully re-animated a couple of old hard drives by giving them a gentle knock from the side with a small hammer. This helps when the mechanical parts (heads or drive motor) are stuck, which happens quite often when the drives haven't been spun up for years.

Cheers

I did try, but got no joy. I could have tried a bit harder I suppose. I have most of all the old software I had for the machine. Bearing in mind I only used this as a games machine with a bit of 3D modelling I haven't really lost much.

Kind regards
Andy

[Avrovulcan]

Originally Posted by alexh

Which version is this? I can't tell from the photos.

If you find out which we can advise you how to upgrade this card. It should have an IDE or SCSI controller and RAM slots. Someone is (or was) remaking GVP SIMMs just recently so you should be able to max it out for not a lot.

If upgrade-able you could consider removing the other two cards (Supra Corp 8MB RAM expansion, GVP Impact II SCSI controller card) as they won't be needed.

If it has IDE you may need the IDE ROM to make it functional, it should be easy to find and an IDE controller would allow the use of a cheap IDE->CF adapter.

Thanks

Its a GVP G-Force 030 Combo 25MHz 030 with FPU and 1MB of RAM Part No. 500025-04. It's a SCSI card with 3 RAM slots. 4MB per slot for a total of 13MB

Regards
Andy

[alexh]

Cool. 4MB GVP SIMMs are still being sold. 3 will set you back about £35 delivered.

http://www.amibay.com/showthread.php...P-accelerators

If £35 is "beer money" then I recommend you get them before they are sold out.

Or take a chance and hold off for a bit and your card might be getting an upgrade allowing for 16MB SIMMS to be used.

http://eab.abime.net/showthread.php?t=98508

[Avrovulcan]

Brilliant. Thanks very much for the info It will certifiably come in handy.

As an aside, I went up into the man cave in my loft (which still needs finishing ) and found all the manuals for the ICD ADSPEED and Megachip. I also found the manual and software for the GVP cards as well. This is quite handy as I haven played around with an Amiga in 25 years and have pretty much forgotten everything
But I'm sure it will come back to me. Ive just been refreshing myself in MSDOS , (something else I hadn't used in many years) as I'm refurbishig and upgrading severl old PC's. Its amazing how quickly it all comes back to you.

[alexh]

If you later decide you want to use a SCSI HDD drive >4GB and partitions greater than 2GB you might want to buy a new SCSI ROM for your controller. The best is the GURUROM. It was being sold up until last year on Amibay for a reasonable £50

http://www.amibay.com/showthread.php...mniscsi-device

The vendor has gone very quiet since the lockdown but you can always register interest.

In that thread is a link to the latest GVPCPUTool which you can use to switch between 68000 and 68030 for compatibility and "MAPROM" to load kickstarts into 32-bit FASTRAM and use the MMU to remap for speed (also reduces the need for kickstart switcher)

https://www.dropbox.com/s/rxwpm78f1i...Tools.zip?dl=0

[Misclegend]

replace the black crt monitor with another one white or beige
do not fit

[Avrovulcan]

Originally Posted by Misclegend

replace the black crt monitor with another one white or beige
do not fit

The Dell monitor is just one I had lying around and it really doesn't fit does it?
The monitor I used with the machine originally was a NEC Multisync 3D. Unfortunately 25 years in storage has been even less kind to it. It powers up but all I'm getting is about 3mm of scanlines across the middle of the display. Considering this did work when the system last powered up I'm working on the assumption that I have a bad joint somewhere on the board inside. This is something I'll tackle once I get the computer done.

Regards
Andy

[McTrinsic]

The removal of the battery leackage does not look so convincing. This would be a major concern to be. Better have an expert look at that. The danger is that residues can continue to destroy the PCB-traces.

Other than that: great machine!

Might consider to get a SCSI2SD.The GuruROM is indeed highly recommended.

[Avrovulcan]

Originally Posted by McTrinsic

The removal of the battery leackage does not look so convincing. This would be a major concern to be. Better have an expert look at that. The danger is that residues can continue to destroy the PCB-traces.

Other than that: great machine!

Might consider to get a SCSI2SD.The GuruROM is indeed highly recommended.

Thanks for the recommendations

As regards the battery leakage, trust me it looks worse than it actually is. In any case I'm an electronics engineer by trade and this sort of repair, is going to be pretty basic considering what I'm used to on a daily basis. But I appreciate the context of your reply

Kind regards
Andy

[Avrovulcan]

My replacement SCSI drive turned up today.
Unfortunately it's a 5.25" hard drive. it would probably work but it will take up far too much space. Serves me right, I shoold have paid more attention to what I was buying.
In any case, it won't go to waste as I have a NUXT PC clone I'm building (I'm going the whole hog and building the PCB from scratch) so it'll go well with that.
Decided to go ahead and buy a SCSI2SD V5.1 from AmigaKit.
Anyone recommend what versions or brands of SD card are reliable to use? Or is it not a big issue.

Kind regards
Andy

[Fastdruid]

Given the relatively low cost of SD cards and that even the slowest are faster than the Amiga can manage I tend to go with the decent brands like SanDisk and a class 10.

I mean an Class 10 16Gb SanDisk Ultra SDHC is all of £4.79 from Amazon on prime.

I don't see much point in going much bigger (and indeed an 4-8Gb may be better suited) so you want SDHC (4-32Gb) rather than SDXC (64Gb+).

But decent brands, SanDisk, Lexar, Transcend. Also for MicroSD (ie via an adapter) add Samsung, Kingston.

[alexh]

I always buy SanDisk and try to get a relatively small one 2GB or something. Don't you have an old card from an old phone and an adapter? Try that first.

[Avrovulcan]

Thanks for the recommendation as regards the SD cards

Believe it or not I dont have much in the way of SD cards hanging around spare. I'll have a look but at today's prices it's just as convenient to pick a brand new one up.

Now, once the SCSI2SD card turns up and I've fitted it along with a new SD card I'm assuming I just run the GVP Faastprep software and format the SD card just like a regular hard drive.?

Regards
Andy