Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: skforty on August 02, 2009, 10:21:06 AM

Title: Upgrading Amiga 500 Ram
Post by: skforty on August 02, 2009, 10:21:06 AM
Hey all,
 
Currently i have 4MB fitted to my GVP expansion and a 512 trapdoor, with 512 internal. I am running into "need ____ ammount of CHIPRAM to run" certain games in WHDLOAD. My question is, how exactly can i upgrade the chip ram? Do i need to change my agnus? If i ordered this, would it be counting towards my Chipram? http://cgi.ebay.com/BaseBoard-4MB-RAM-Expansion-for-Commodore-Amiga-500_W0QQitemZ400064053127QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item5d25acff87&_trksid=p3286.c0.m14
 
 
So one note, i just put a 8372A for my pal/ntsc switch.  It looks like this chip is actually 1MB, but its not showing up as 1MB in workbench.
 
Thanks for all the help!
Title: Re: Upgrading Amiga 500 Ram
Post by: amigakit on August 02, 2009, 11:02:00 AM
Hello,

To upgrade Chip Memory to full 2MB on an A500 or A2000, you should use the Mini Megi Chip (http://amigakit.leamancomputing.com/catalog/USD.php?url=product_info.php?products_id=915):

http://amigakit.leamancomputing.com/catalog/USD.php?url=product_info.php?products_id=915
Title: Re: Upgrading Amiga 500 Ram
Post by: orange on August 02, 2009, 11:30:47 AM
its easy (and free!) to change the trapdoor 512k into chip ram. aminet is full of guides about it.
you just need to change few traces on motherboard.

minimegi is better of course, but pretty expensive :(
Title: Re: Upgrading Amiga 500 Ram
Post by: skforty on August 02, 2009, 12:09:13 PM
So i have a revision 5 a500, and just did the hack.  Where i cut the trace between middle and bottom of j2 and then bridge middle and upper...then lift pin 32 on gary...It took 512 off of my fast ram, but my chip ram is still 512...any suggestions?
Title: Re: Upgrading Amiga 500 Ram
Post by: orange on August 02, 2009, 12:33:38 PM
er, did you "Cut Trace Above Solder Point Across From Pin 8" near expansion connector?
( http://aminet.net/docs/hard/1MBChip.lha )
Title: Re: Upgrading Amiga 500 Ram
Post by: skforty on August 02, 2009, 12:41:10 PM
That guide says, "cut the trace, or lift the gary pin".  Either way its just making sure exram is connected to ground.
Title: Re: Upgrading Amiga 500 Ram
Post by: whiteb on August 02, 2009, 01:02:52 PM
Quote from: skforty;517731
Hey all,
 
Currently i have 4MB fitted to my GVP expansion and a 512 trapdoor, with 512 internal. I am running into "need ____ ammount of CHIPRAM to run" certain games in WHDLOAD. My question is, how exactly can i upgrade the chip ram? Do i need to change my agnus? If i ordered this, would it be counting towards my Chipram? http://cgi.ebay.com/BaseBoard-4MB-RAM-Expansion-for-Commodore-Amiga-500_W0QQitemZ400064053127QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item5d25acff87&_trksid=p3286.c0.m14
 
 
So one note, i just put a 8372A for my pal/ntsc switch.  It looks like this chip is actually 1MB, but its not showing up as 1MB in workbench.
 
Thanks for all the help!


Agnus itself does not ADD ram to the Machine.  Agnus controls ADDRESSING of available ram, and determines access by the custom chips, to Chip Ram (Because the Custom Chips access it).

By upgrading the Agnus, you upgrade the capability of the chip to control MORE ram as Chip ram.  Fatter Agnus can handle 1MB of Ram, as CHIP ram and SUPER Agnus controlled up to 2MB of ram, as CHIP.

If you modded your A500 to 1MB of chip, and use a 1MB Agnus, then you will have no FAST ram available.  Then yes, as Workbench loads, then CHIPRAM will be used, that is why it does NOT have 1MB.

If you open a Shell, and type 'Avail'  you should get a Breakdown of what is being used, and TOTAL ram.  I think you will find Ram is being 'Used'.

Because Workbench is using MOST of your ram, Whdload (even the simplest of games) will not run.  Some games need around 4MB of FAST Ram (IF you preload the disks), as well as 1MB of Chipram.
Title: Re: Upgrading Amiga 500 Ram
Post by: skforty on August 02, 2009, 01:14:38 PM
Thanks for the explanation, however, my graphic/chip ram is staying the same...when i use avail or perf tool it shows me as having 4MB fast ram and .5 MB of chipram...So it seems as its not working.
Title: Re: Upgrading Amiga 500 Ram
Post by: skforty on August 02, 2009, 01:28:55 PM
So im not sure what changed...I started getting green screen on boot...So then i desoldered the upper jumpers, and reclosed the bottom 2. Everything was happy again. Then i desoldered all the jumpers clean. And covered both middle and top jumpers completely....its working now. (http://eab.abime.net/images/smilies/smile.gif) I mustve still had a connection to bottom or something?...who knows...anyways its working now. Thanks for the help!
Title: Re: Upgrading Amiga 500 Ram
Post by: tone007 on August 02, 2009, 01:35:21 PM
...great, now I feel like pulling out one of my older A500s and cutting some traces ;)