A500 rev 6a Motherboard Ram Chips Type

[Mark sealey]

Hi all...bit of a noob question....what type size/spec are these ram chips...?

Im replacing upgrading my a500 to a A500+

where can i buy them....?

thanks

[Vypr]

Assuming you are upgrading a Rev 6a or higher board, These should work:

https://www.ebay.co.uk/itm/5pcs-MCM5...item3d50f39d12

Remember to also fit the decoupling capacitors which are ceramic type 0.33 uF
Also, while it is best practice to fit DIL sockets, the placement of hte RAM chipson the board means that the keyboard may have problems fitting on top so it is usually a better idea to fit chips directly onto the board.

[Mark sealey]

Originally Posted by Vypr

Assuming you are upgrading a Rev 6a or higher board, These should work:

https://www.ebay.co.uk/itm/5pcs-MCM5...item3d50f39d12

Remember to also fit the decoupling capacitors which are ceramic type 0.33 uF
Also, while it is best practice to fit DIL sockets, the placement of hte RAM chipson the board means that the keyboard may have problems fitting on top so it is usually a better idea to fit chips directly onto the board.

Thank you for your reply.

[jbilander]

You can use those ultra-flat sockets, but I would rather just leave it as is and only use a 2 mb ram trapdoor expansion, giving you a total of 1mb chip and 1.5mb slow with the gary adapter + jumper wire.

http://eab.abime.net/showthread.php?t=97077

[8 Bit Dreams]

There is a problem to get these ultra-flat sockets. Wasn't able to find them till now..

[Mark sealey]

Awesome...well i have bought another A500 from Ebay..its all boxed etc...and powers up ok acording to the seller...i did ask if the power led is constant and not flashing...and the drive is "ticking2 waiting for a disk etc.

I have also Bought a Individual Computers A512 Chip ram expansion that has a "though port"

So im guessing I will have 512k on bored chip...512k Trapdoor chip....If i did the Chip ram mod that would give me 1mb on bored and 512k trapdoor chip ram...?

[Vypr]

Originally Posted by Mark sealey

Awesome...well i have bought another A500 from Ebay..its all boxed etc...and powers up ok acording to the seller...i did ask if the power led is constant and not flashing...and the drive is "ticking2 waiting for a disk etc.

I have also Bought a Individual Computers A512 Chip ram expansion that has a "though port"

So im guessing I will have 512k on bored chip...512k Trapdoor chip....If i did the Chip ram mod that would give me 1mb on bored and 512k trapdoor chip ram...?

The modification disables the RAM expansion port

[Mark sealey]

Ah....right...thank you.....just wish there was a way to get 2mb chip on a A500.

[watman]

Originally Posted by Mark sealey

Ah....right...thank you.....just wish there was a way to get 2mb chip on a A500.

There is
If you have mainboard rev 8.1A it's a matter of adding ram chips and demultiplexer onboard, if you have lower rev, you need a MegAChip (or clone) addon.

[jbilander]

With rev 6A you can replace with a fatter Agnus chip (318069-18 (PAL), 318069-19 (NTSC), 318069-03) and do the mod below to get 2mb chip ram, but I doubt it is worth it if you are not heavy into graphics or music on your A500. 1mb chip and some slow ram will take you far in terms of playing games. Probably better to put your money on an Accelerator card such as tf534 and get an 030 cpu and 4mb of fast ram, a WHDLoad dream machine

http://www.rasterline.com/images/ami..._2MEG_CHIP.jpg

[Mark sealey]

Originally Posted by watman

There is
If you have mainboard rev 8.1A it's a matter of adding ram chips and demultiplexer onboard, if you have lower rev, you need a MegAChip (or clone) addon.

Thanks for the reply....been looking into this alot over the weekend...got my A500 Rev 6a mobo.....with the OS1.3 rom the 512k on bored and 512k in the trapdoor (individual computers A512) is seen and chip ram....with my OS3.1.4 rom its seen as 512k chip...512k slow ram.....interesting change with a OS rom.

I have seen a CDTV/a500 ram explanation that replaces Agnus.

also the Individual Computers ACE2.....Also the All singing all dancing ACA 500+ that magically turns your trap door ram into Chip ram.


What im trying to do is get the spec as close as i can to my A600 furia...with IDE of some sort....so at the moment the ACA500+ looks like the Ideal solution at th moment.