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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: acharris05 on September 03, 2007, 10:41:45 AM

Title: Strange A1200 floppy disc problem
Post by: acharris05 on September 03, 2007, 10:41:45 AM

Hi all, I need some advice.  I have an Amiga 1200 with a 8 Mb Ram expansion board and 240 Gb HDD.  The amiga works fine from the HDD, but I can't get the 1200 to read any floppy I put in the machine from either DF0: or my 2 external floppy drives.

I tried putting a floppy disc game in the drive to start the Amiga, so that it will bypass the HDD and load from floppy, but after a few seconds it will switch to HDD and load WB up.  

I can format the floppy discs in any of DF:0, DF:1 and DF:2, but I can't seem to read or open a disc to viewthe contents in any of the floppy drives.  Also I am getting like a fishy smell from my A1200, which I would assume means that something is burning.

So what part of the motherboard controls the floppy read access, and what is the fix, as I am not fully up on the internal workings of a A1200 only know basic, though I do know PC's. Any help is appreciated.

Anthony

Title: Re: Strange A1200 floppy disc problem
Post by: rkauer on September 03, 2007, 10:59:23 AM

 Looks like one CIA chip is broke. Hard to repair.

 Buy a spare motherboard from ebay, vesalia, sothut or amigakit...
--------------------

 Hummmmmmm.......
 Second tought.

 Try this first (before you throw the towel): in  a cli, type "diskchange df0:". Try to read again the floppy. No good? Ok, it's time to throw the towell. :-(

Title: Re: Strange A1200 floppy disc problem
Post by: acharris05 on September 03, 2007, 01:18:44 PM

Thanks for the advice.  Good thing I got a few A1200 knocking around all working.  I will have to swap one over.  Thanks again.

Anthony

Title: Re: Strange A1200 floppy disc problem
Post by: Gwion on September 03, 2007, 04:43:31 PM

Or they could be disabled in the quick boot option menu!

Title: Re: Strange A1200 floppy disc problem
Post by: murple on September 03, 2007, 07:00:43 PM

The quick boot menu options can't be saved between boots though, can they?

Title: Re: Strange A1200 floppy disc problem
Post by: Gwion on September 04, 2007, 07:33:35 AM

I think it can if it has a onboard battery! But im not to sure

Title: Re: Strange A1200 floppy disc problem
Post by: weirdami on September 04, 2007, 08:29:42 AM

@acharris05

Quote

Good thing I got a few A1200 knocking around all working. I will have to swap one over.

Why not just use one of the working A1200's?

Title: Re: Strange A1200 floppy disc problem
Post by: Damion on September 04, 2007, 09:27:17 AM

Quote

weirdami wrote:

Why not just use one of the working A1200's?

:roll:

Let me make an absolutely -WILD- guess... probably because he's trying to figure out what's wrong with the one he's using now??

Title: Re: Strange A1200 floppy disc problem
Post by: acharris05 on September 04, 2007, 06:36:28 PM

Hi, and thanks for the replies.  Yes I will use another 1200 and transfer the HDD and Ram expansion, but I was looking to see if there was a simple solution to this problem, and also to learn a little more about the A1200 and what chips control what, as oppsose to just swap amiga's and never learn nothing about the working of the Amigas.

Anthony

Title: Re: Strange A1200 floppy disc problem
Post by: CLS2086 on September 04, 2007, 06:42:52 PM

Hi,
in this case AmigaCenter can repair your A1200 and change the dead CIA.
But first, try to unplug the internal floppy. The A1200 can boot on DF1 with the Kickstart menu !

Title: Re: Strange A1200 floppy disc problem
Post by: rkauer on September 04, 2007, 06:50:37 PM

 Then I do you a quick (and superficial) lesson:

 - Alice controls memory (and a small part of video generation), like its predecessor, Agnus;

 - Lisa does all the hard video job, (before was Denise ECS and OCS);

 - Paula does the audio and a little part of timing control for the floppy ports (in all Miggys);

 - CIAs (even and odd) controls directly the ports (floppy, ext floppy, serial, parallel, joy & mouse);

 - ROM keeps the basic routines in order to the Amiga boot.

 - CPU runs the programs (d'oh!) and controls the FastRAM (only acessed by itself), in the case of accelerators.

 More details to come... Someday:roll: