A600 motherboard revisions

[HamStar50]

Hi guys,

Still walking my first steps on the Amiga chaps - bought a rev 1.5 motherboard (by accident) to replace my rev 1.0 motherboard. Any noticeable differences? I mean physically I saw a resister wired between 2 pins on a chip near the power port (just beneath the cluster of capacitors). Anyone know why there are revisions?

 

[Justin]

lot's info here m8

http://www.amiga-hardware.com/showhardware.cgi?HARDID=10

but usually mobo revisions were for cost cutting and timing fixes

 

[HamStar50]

Cheers mate - nothing amazing then

 

[alexh]

I don't think anyone really knows. I asked many years ago with no reply.

The reason behind board re-spins are usually :

• A re-work of mistakes on earlier production PCB's which were fixed with "expensive" cut-n-shut jumper wires.
• Cost reductions. Usually a company will try and source the cheapest price for parts, if there can be a significant saving using a comparable part with a different PCB form factor they will re-spin the board.
• Tooling changes. If the factory changes the equipment it uses to make the PCB sometimes the PCB has to be re-worked.

I'd really like to see the ERRATA between the different Commodore schematics but I am pretty sure that data is lost.

 

[AmiNeo]

In my experience (not a heck of a lot but a bit) I've noticed nothing between all the revisions in terms of performance / compatability.

It's entirely possible they just used different parts over the years as different components became cheaper / more expensive and shifted the board around in minor places to compensate.

 

[Justin]

it does seem to be only the 1200 that suffers the most between revisions (and the early A2000)

 

[rkauer]

The A600 have its share of problems in early revisions. But those are related to accelerators (the new ACA630), mostly.

 

[alexh]

Yes? I've not seen anything... please point me in the direction where I can read about it.

I've got a 1.0 and a 1.5 and my ACA630 30MHz is working fine (albeit not extensively tested) in the 1.0

 

[rkauer]

Mate, I remember seeing some threads about 1.0 revisions & accelerators.

But may be due to the micro-fractures on old solder points Jens told about some time ago.

 

[AmiNeo]

End of the day, hes either gonna have no problems with a 1.5 or better compatability. tie or win situation. No lose

 

[Khyron]

1.0 and 1.3 seem to be almost the same, there's nothing easily spotted, but I assume that if there is a change, it would probably be gayle related since the GAL was removed on most 1.3 boards.

1.5 changes the jumpers for the GAL so that they're closed by default so there's no need to solder them in like on 1.0-1.3, and there was a bad attempt to clean up the poor power supply to the video encoder, which didn't work so you'll see the cap soldered there on all 1.5's (and some 1.3's) to take care of excessive noise from the PCMCIA signals and floppy power drain.

2X removes the GAL artwork all together and the signaling was completely rerouted around the PCMCIA and Video encoder, which cleans up the video out noise considerably..

 

[HamStar50]

Wow...

Being new to the hardware aspect of Amigas, I didn't realise they were so poorly made! As I mentioned on my recently purchased 1.5 board, there a chip near the power socket which has a resister soldered between 2 pins on the same IC. Just looked like shoddy design really.

 

[rkauer]

The chip near the power connector is the video composite generator (CXA1145), and over it the piece is a filter capacitor.

 

[Timtheloon]

I recently discovered that one of my A600's is A rev 1 (type 1) I believe when looking at the pictures on BBOAH.

Is there any rarity in A600 Motherboards like you have with certain A4000 & A1200 mobo's

 

[SilentBob]

Sorry to update this old thread, but I have two A600's that are both 1.5 revision boards, but with very slight differences.

I've noticed two things. Different caps were used, the yellow composite connector looks different like the one used in the 2B board. The white audio connector looks different as well.

View attachment 2428590