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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: crawff on May 27, 2010, 10:42:43 PM

Title: Why low memory on my a1200?
Post by: crawff on May 27, 2010, 10:42:43 PM
Hi,

I have a A1200 which has a 6GB hard drive which is split into 2 separate 3GB drives.

My 1200 is stock with my no upgrades.

I cannot boot into HD0 as this is loaded with AmigSYS 4? and will start loading and then crash. This is ok because i think it is because i need more memory to run this.

I can boot from HD1 which loads into workbench 3.0 fine. The issue i have is that my available memory is around 750k and i cannot get many games to work. Some games work fine from the floppy drive but every game i install also fails to load because of not enough memory.

How do i free up my memory back to 2MB? so i can load some more games. All the WHDload games also do not load. Is it normal to only have 750k memory when first booting into workbench?

Thanks guys,
Title: Re: Why low memory on my a1200?
Post by: Karlos on May 27, 2010, 10:46:15 PM
Simply having a hard disk uses memory, as a certain amount is reserved for buffers etc. You can actually change this in your startup sequence by using the addbuffers command with a negative buffer count.

2MB of chip ram is not going to get you far, no matter how much you strip from your configuration.

The best thing you can do is add more memory. Even a basic 4MB of trapdoor ram will be a significant improvement in performance terms.

-edit-

How are you supporting the 6GB drive btw? I thought that you needed OS3.5/3.9 or 3.1 with NSD to support drives > 4GB
Title: Re: Why low memory on my a1200?
Post by: Thomas on May 27, 2010, 10:49:54 PM
Quote
I have a A1200 which has a 6GB hard drive which is split into 2 separate 3GB drives.

My 1200 is stock with my no upgrades.


This won't work. A stock AmigaOS cannot handle more than 4GB. Your data is at high risk. You will loose everything sooner or later.

Quote
How do i free up my memory back to 2MB?


You can't. Without a gfx card and without FastRAM you won't get more than 1300 ~ 1500 KB. The rest is needed for display, sound, floppy DMA and operating system.

To free memory, reduce size and depth of the Workbench screen, reduce number of partitions, number of buffers per partition and file system block size.
Title: Re: Why low memory on my a1200?
Post by: crawff on May 27, 2010, 10:51:03 PM
Ok thanks,

If i insert a floppy disk game and boot it from a fresh restart, will i have the full memory available to me? as it didn't have to load the hard drive?
Title: Re: Why low memory on my a1200?
Post by: Karlos on May 27, 2010, 10:53:35 PM
Quote from: crawff;561429
Ok thanks,

If i insert a floppy disk game and boot it from a fresh restart, will i have the full memory available to me? as it didn't have to load the hard drive?


This isn't enough. Unless the floppy is a game that takes over the system, your HD will still be mounted by the OS. To prevent that, you need to disable them from the early startup menu which you can get by (re)booting with both mouse buttons held.
Title: Re: Why low memory on my a1200?
Post by: crawff on May 27, 2010, 10:56:37 PM
Thank you both for your help :-)
Title: Re: Why low memory on my a1200?
Post by: Karlos on May 27, 2010, 11:00:48 PM
Quote from: crawff;561431
Thank you both for your help :-)


Until such time as you can upgrade, what I would suggest is, repartition your 6GB drives into a few partitions all of which are below the 4GB limit and leave the upper 2GB empty.

Writing beyond the 4GB boundary without proper large HD support (such as is found in OS3.5+) is going to destroy your data.
Title: Re: Why low memory on my a1200?
Post by: Tajmaster on May 27, 2010, 11:57:20 PM
This may sound like an obvious answer but just buy some extra RAM or an accelerator, problem solved :)
Title: Re: Why low memory on my a1200?
Post by: illy5603 on May 28, 2010, 12:17:58 AM
Quote from: Tajmaster;561463
This may sound like an obvious answer but just buy some extra RAM or an accelerator, problem solved :)

That's pretty much it. I can't imagine running an A1200 with a hard disk without at least more memory. Otherwise it is a floppy disk gaming machine.
Title: Re: Why low memory on my a1200?
Post by: Karlos on May 28, 2010, 12:19:27 AM
Quote from: Tajmaster;561463
This may sound like an obvious answer but just buy some extra RAM or an accelerator, problem solved :)


Granted, but that doesn't fix the HD size issue.
Title: Re: Why low memory on my a1200?
Post by: Karlos on May 28, 2010, 12:21:01 AM
Quote from: illy5603;561473
That's pretty much it. I can't imagine running an A1200 with a hard disk without at least more memory. Otherwise it is a floppy disk gaming machine.


I did it for a brief while between selling a memory expansion and saving for my first accelerator card.

The difference from 14MHz 020/2MB chip ram only to 25MHz 68040/16MB fast was pretty astounding :)