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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Pinballer on June 01, 2014, 07:33:57 AM

Title: A1200 accelerators - all have timing issues??
Post by: Pinballer on June 01, 2014, 07:33:57 AM
I suspect the problem I am having with my A1200 (Rev2B motherboard) and  the 1230-28 accelerator is due to timing issues.  I have read that to  resolve this issue it requires removal and replacement of some  components on the A1200 motherboard.  Not sure exactly what is required.

My question is, has the designer/manufacturer corrected the timing  issues with the newer accelerator cards?  Such as the the 1220 or 1232  accelerators?  Or do all A1200 (Rev2B) motherboards require the mods to  correct the timing/crashing issues I'm experiencing with mine?

Any help greatly appreciated.

Original thread when attempting to diagnose the problem with my system locking up....
http://www.amiga.org/forums/showthread.php?t=67449
Title: Re: A1200 accelerators - all have timing issues??
Post by: Lurch on June 01, 2014, 07:53:25 AM
Mainly the ACA accelerators... old meeting new clashing. Some 060 accelerators also have issues.

The other thing to get done is the caps at the same time. Amigakit offer a good service to have this done.

It's not the accelerators at fault but it's showing up faults in the Amiga 1200 boards.
Title: Re: A1200 accelerators - all have timing issues??
Post by: Lurch on June 01, 2014, 07:56:17 AM
This site is a good read:

http://www.ianstedman.co.uk/Amiga/amiga_hacks/A1200_Mobo_fix/a1200_mobo_fix.html

Service from Amigakit

http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=1020
Title: Re: A1200 accelerators - all have timing issues??
Post by: Pinballer on June 01, 2014, 07:56:33 AM
Thanks for the reply Lurch.  The strange thing is my motherboard was recapped last year according to the sticker inside it when I got it recently.

Is it just the older revision from ACA, or even the newer version all have issues?

Are their any accelerators that don't have this issue?

Does anyone have a link to the mods required to the A1200 motherboard to correct the issue with the ACA accelerators?
Title: Re: A1200 accelerators - all have timing issues??
Post by: Lurch on June 01, 2014, 07:58:12 AM
See my second post above :-) All ACA, some Apollo's and Blizzards but less likely.

If the motherboard is already re capped then just need the timing fixes.

Older accelerators are mostly fine.
Title: Re: A1200 accelerators - all have timing issues??
Post by: som99 on June 01, 2014, 09:22:16 AM
Check the first link from Lurch, many 2B boards are fine after just removing E123C and E125C so you can start of trying that before you continue.
Have you ever removed SMD resistors and such before? They are not only soldered but has a tiny dab of glue underneath, takes it slow and you should be fine, don't use to much heat when removing the SMD's tho :)
Title: Re: A1200 accelerators - all have timing issues??
Post by: Pinballer on June 01, 2014, 09:51:09 AM
No I never have removed a SMD component.  Do I just heat either end with a small iron tip and use solderwick, then pry the component off the board gently?
Title: Re: A1200 accelerators - all have timing issues??
Post by: Astral on June 01, 2014, 10:05:58 AM
I've got to say - the whole timing fix thing from my perspective seems to be a big bucket load of codswallop. I've tried so many different accelerators on so many different A1200's and NEVER had to be concerned with timing fixes of any kind. Yes, logically this may be just entirely co-incidental in that all the 1200's I've had over the years have been timing fixed without me knowing it, or I've been lucky...who knows. I've tried PPC's, 1260's, ACA's, Apollo's and so on. Different revision motherboards. Demos, games, music, graphics, workbench proggies. Not a problem due to any lack of a "timing fix". I'll admit I've never looked into it from a technical perspective, as to why it might be needed, but maybe the whole timing fix thing is just an 'ol wives tale? Is there something specific to the 1200 that makes it that no other Amiga model needs timing fixes also? Because noone ever says "Oh...the Mtec 68020 needs a Rev 6 motherboard with timing fixes" - why not? Go figure...

On a similar note being a trade qualified mechanic I was O V E R people commenting about batteries being stored on cement, and how it damages them. Absolutely over it. Noone could ever say why. Or how long it took. Or exactly why it damaged them. But yet somehow everybody seemed to know that it damaged them! So, in short, I performed a "scientific" test over a period of 6 months using 4 brand new identical batteries under controlled conditions and my conclusion was that it was an absolute myth!

Disclaimer: Just my findings :D
Title: Re: A1200 accelerators - all have timing issues??
Post by: Lurch on June 01, 2014, 10:19:06 AM
Had an ACA card and a 1200, would red screen on occasion. Hang and lock-up. Had the timing fixes applied now it's rock solid.

So not a myth.
Title: Re: A1200 accelerators - all have timing issues??
Post by: Havie on June 01, 2014, 11:00:36 AM
Quote from: Astral;765455
I've got to say - the whole timing fix thing from my perspective seems to be a big bucket load of codswallop. I've tried so many different accelerators on so many different A1200's and NEVER had to be concerned with timing fixes of any kind. Yes, logically this may be just entirely co-incidental in that all the 1200's I've had over the years have been timing fixed without me knowing it, or I've been lucky...who knows. I've tried PPC's, 1260's, ACA's, Apollo's and so on. Different revision motherboards. Demos, games, music, graphics, workbench proggies. Not a problem due to any lack of a "timing fix". I'll admit I've never looked into it from a technical perspective, as to why it might be needed, but maybe the whole timing fix thing is just an 'ol wives tale? Is there something specific to the 1200 that makes it that no other Amiga model needs timing fixes also? Because noone ever says "Oh...the Mtec 68020 needs a Rev 6 motherboard with timing fixes" - why not? Go figure...
 
On a similar note being a trade qualified mechanic I was O V E R people commenting about batteries being stored on cement, and how it damages them. Absolutely over it. Noone could ever say why. Or how long it took. Or exactly why it damaged them. But yet somehow everybody seemed to know that it damaged them! So, in short, I performed a "scientific" test over a period of 6 months using 4 brand new identical batteries under controlled conditions and my conclusion was that it was an absolute myth!
 
Disclaimer: Just my findings :D
Well - back in the day with my Apollo 040 40mhz it was constantly crashing (and hadn't with the 28mhz blizzard). Sent for a timing fix and it never crashed again. My understanding is only certain revisions of motherboards (I think early Commodore ones) need the fix and only 040+ accelerators. it certainly is not a myth!
Title: Re: A1200 accelerators - all have timing issues??
Post by: som99 on June 01, 2014, 11:15:19 AM
Not a myth at all, I could not get my Amiga stable at all with the ACA1231/42Mhz, I got a lot of weird crashes/gurus within secons/minutes in a lot of programs/games and also WB crashes, after performing the timing fix on my 2B motherboard all issues dissapeared and everything have been working perfect since :)

You can read a bit about it on the link Lurch posted to get a better understanding why it's needed http://www.ianstedman.co.uk/Amiga/amiga_hacks/A1200_Mobo_fix/a1200_mobo_fix.html

There are more technical information to find if you search around a bit.


Quote from: Pinballer;765454
No I never have removed a SMD component.  Do I just heat either end with a small iron tip and use solderwick, then pry the component off the board gently?

There are a few different techniques to do so, all depends on what equipment you got, just google "remove SMD resistors" end see what feels doable for you, I myself use a SMD puller and a soldering iron and heat/pull/heat/pull and done, ive also done with a "tin sucker" (dont know the english name for it) and also tried with a desolder/heatgun. But to be safe don't use to high temerature when desoldering one.

But im planning on buying an SMD Rework Station to make life easier :)
Title: Re: A1200 accelerators - all have timing issues??
Post by: jj on June 01, 2014, 01:00:27 PM
The faster boards like the apollo and the newer ones do have issues because they are not buffered.  That is why the blizzards were always rock stable but didn't reach the speeds of the other boards.
Title: Re: A1200 accelerators - all have timing issues??
Post by: Pinballer on June 02, 2014, 09:16:14 PM
Thanks for the replies, very useful information.
Title: Re: A1200 accelerators - all have timing issues??
Post by: Buzzfuzz on June 03, 2014, 06:07:51 AM
I don't have much problems with ACA's or Blizzards, that said, my 1232 locks  up when I insert my transfer card in the PCMCIA slot.


 It seems Blizzard PPC's and Apollo's run best on 1B boards, my 1230/56 ACA's  are both on 2B boards and also run fine.


 Blizzard 1230's will work on all of them, most of them have 32 MB which is  more than enough for games.


 I've encountered the most problems with ACA's on 1D4 boards, so these do need  timing fixes if you want to use a board like that, so to sum up:


No not all boards need timing fixes when you pop in an accelerator.
And like they say, if it ain't broken, don't try to fix it.


Also when using ACA's keep tweaking with WHDLoad and ACA parameters until you got it stable.