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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: chriscampbell on August 24, 2021, 07:57:04 PM

Title: Advice needed on RAM Chips for A500
Post by: chriscampbell on August 24, 2021, 07:57:04 PM
Hi everyone,

I am hoping that someone can help me out a bit here.  I have been working on cleaning up and upgrading my Amiga 500.  I keep getting the occasional yellow screen on boot. After doing a lot of reading it looked like my CPU was maybe trying to write to some bad RAM.  On one of my stable boots I ran a RAM test and sure enough I came back with a problem in one of my chips.  I am looking to replace them but I am not sure how to find a replacement.  I looked on ebay and found a couple of sellers who were sellling some obviously cut up boards.

https://www.ebay.co.uk/itm/224503285754?hash=item34457047fa:g:eUUAAOSwKIlgzfMB (https://www.ebay.co.uk/itm/224503285754?hash=item34457047fa:g:eUUAAOSwKIlgzfMB)

I have an Amiga 500 Rev 6A board that has 512 kb of RAM on it in 4 chips. Would this be what I would be looking to get?  Or is there another root I can go where new chips may be available? Any help would be appreciated. Thank you.
Title: Re: Advice needed on RAM Chips for A500
Post by: Castellen on August 26, 2021, 09:09:38 PM
The 256kb x 4bit DRAMs are easy enough to find as new old stock on Ebay, search for TC514256AP.  The speed doesn't matter, i.e. you can use -70 or -80 parts.  Make sure the package type is DIP20, not ZIP.

You can populate the other 4 optional ICs for a full 1MB on board if you don't already have a 512kB expansion module, though you'll need to move a couple of links on the board to make this work.
Title: Re: Advice needed on RAM Chips for A500
Post by: chriscampbell on August 31, 2021, 06:16:45 PM
Thanks.  I will look that up and order some. Hopefully I can get my A500 back on its feet.