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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Lurch on March 17, 2011, 06:03:08 AM

Title: Strange A590 mod
Post by: Lurch on March 17, 2011, 06:03:08 AM
Trying to work out the mod that's been done to an A590 PCB before I go connecting power to it ;-)

Photo attached, seems to run from the memory jumper to a a chip I can't quite make out. Will be probably remove it.

http://www.flickr.com/photos/60671882@N06/5530782057/
Title: Re: Strange A590 mod
Post by: Jiffy on March 17, 2011, 07:10:09 AM
Quote from: Lurch;622391
Will be probably remove it.

Why?
Title: Re: Strange A590 mod
Post by: alexh on March 17, 2011, 09:10:00 AM
Your photo is terrible, you cannot deduce anything from it.

Are you sure it is a home-made mod?

If you look at this photo of an A590 motherboard (Ignore the two power mod wires.)

(http://members.iinet.net.au/~davem2/overclock/a590.jpg)

There is a similar wire on this A590 motherboard (blue wire)

It looks like it could be a factory mod (i.e. to fix a PCB flaw)?

Leave it alone?
Title: Re: Strange A590 mod
Post by: a1200 on March 17, 2011, 10:01:45 AM
Agreed, they used to put traces on boards after they had done a run and subsequently found a bug - cheaper than doing 1000's more boards and throwing the rest away! You notice on most Amiga PCB's there is a revision number - the later revisions fix problems they have found in the previous versions, so the next run of those boards might not have that on. It was common practice back then.
Title: Re: Strange A590 mod
Post by: Matt_H on March 17, 2011, 11:36:23 AM
Indeed. That looks like a factory-installed patch wire. Most A1200s have one of these, too (took them several revisions to incorporate it into the PCB).
Title: Re: Strange A590 mod
Post by: Lurch on March 17, 2011, 05:43:36 PM
First A590 I've seen with it, plus it doesn't look like the blue wire and has a lot of glue stuck all over it which you can see in my crappy photo.

Ah well will have a play on the weekend.
Title: Re: Strange A590 mod
Post by: Matt_H on March 17, 2011, 09:26:57 PM
Most factory patches are glued like that. Strongly suggest not playing with it. (Does the 590 work?)
Title: Re: Strange A590 mod
Post by: Lurch on March 17, 2011, 10:53:18 PM
Not sure if it's working, was marked as bad. Trying to get a working A590 from this PCB and my old one which decided to melt one of the memory chips.

Will find out today when I get home, if all is good I have some V7 ROM's and some new RAM on it's way.

If not it's back to hunting for a working A590, was offered one for 75 euro's but that's more than I really want to spend on it.
Title: Re: Strange A590 mod
Post by: alexh on March 18, 2011, 08:52:58 AM
For less than €75 you could get the superior GVP Impact II HD8+
Title: Re: Strange A590 mod
Post by: cv643d on March 18, 2011, 10:09:37 AM
Quote from: alexh;622732
For less than €75 you could get the superior GVP Impact II HD8+


And for e7.5 you could get the superior A600 with the built in IDE-interface (just ask Alexh where that famous flee market full of second hand cheap A600 is located) :)
Title: Re: Strange A590 mod
Post by: alexh on March 18, 2011, 10:24:01 AM
Sit on eBay UK for 2-3 weeks and you'll get a (yellowed) working A600 for under €30

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300531567214

If you're willing to take a gamble... much much less.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280642802748
Title: Re: Strange A590 mod
Post by: Lurch on March 21, 2011, 04:34:10 AM
Quote from: alexh;622732
For less than €75 you could get the superior GVP Impact II HD8+


LOL Cheapest one I've seen is $110 euros + shipping on that :)

Anyway the RAM works on the "new" A590 PCB, just need to suss out a scsi HDD and the new PCB has a different power connector for the HDD so will need to sort out what to try there.
Title: Re: Strange A590 mod
Post by: Lurch on March 21, 2011, 05:39:13 AM
After looking at it closer the new PCB is using a standard molex connector were the old PCB was using a weird Commodore connection.  The power connector has the strange connection at one end then the molex connector at the other, so will just swap the strange connector over to a molex connector and see what happens ;)

On another note if I put in a larger than 4GB HDD and partition it as 4GB would there be any issues?
Title: Re: Strange A590 mod
Post by: Jiffy on March 21, 2011, 07:18:52 AM
Quote from: Lurch;623405
On another note if I put in a larger than 4GB HDD and partition it as 4GB would there be any issues?

Nope. There's a chance it will be recognised by HDtools as something entirely different, but just correct those figures until they represent the correct values.

For example: I have had an 20 GB drive I used for testing showing up as 60 MB. After partitioning (which took a while to figure out), it worked without problems.
Title: Re: Strange A590 mod
Post by: Lurch on March 21, 2011, 07:24:27 AM
Quote from: Jiffy;623416
Nope. There's a chance it will be recognised by HDtools as something entirely different, but just correct those figures until they represent the correct values.

For example: I have had an 20 GB drive I used for testing showing up as 60 MB. After partitioning (which took a while to figure out), it worked without problems.


Nice, that's good news as I can get my hands on some cheap drives but they're all 37GB. Have to purchase a 50pin to 68pin adapter though but they're pretty cheap :)

Thanks for the NFO Jiffy, just worried about the power adapter but will find out tomorrow when I give it a shot :-)
Title: Re: Strange A590 mod
Post by: psxphill on March 21, 2011, 07:44:26 AM
Quote from: cv643d;622747
And for e7.5 you could get the superior A600 with the built in IDE-interface

a500 & a600 are pretty much on the same par, the built in ide is not as good as a gvp (probably not even as good as an a590).