upgrading fast ram in an A3000

AMIGAZ · 06 February 2005, 11:22

My current memory setup in my A3000 is 2mb chip and 4mb fast and I've bought 16 pcs of 256k x 4 page mode 20 pin zip modules that I want to expand my fast ram with but the problem is that I don't know what type I have in now (have 8 modules attached) and if I can mix the ones I bought with the ones I have and how to arrange them in the sockets (just fill all sockets up)
I've attached some pics of how they are arranged now and the numbers can be seen on them.
Hope someone can help me, don't want to post at Amiga.org yet because it sometimes seem that they ingnore people with less than 500 posts

patrik · 06 February 2005, 15:31

@AMIGAZ:

You can only have one size of zips in the A3000 - either 256kx4 or 1Mx4. You set the size of the used zips with the J852 jumper which is located between the videoslot portion going to the daughterboard and the Super DMAC. Currently you have 4MB fastram in 8 chips which makes the zips have the size 1Mx4, thus you wont be able add more memory using your 256kx4 zips

.

If you look the printing on the motherboard, you will see that each zip-socket is labeled - from U850 to U881. These 32 zip-sockets are divided in four banks of 8 zip-sockets each and when expanding the memory you must fill a bank completely. U850 to U857 is the first bank, U858 to U865 is the second bank, U866 to 873 is the third bank and U874 to 881 is the fourth bank.

Also stumbled upon the A3000 manual, it has lots of info and is probably more accurate than me :=).

/Patrik

AMIGAZ · 06 February 2005, 15:47

Quote:

Originally Posted by patrik

@AMIGAZ:

You can only have one size of zips in the A3000 - either 256kx4 or 1Mx4. You set the size of the used zips with the J852 jumper which is located between the videoslot portion going to the daughterboard and the Super DMAC. Currently you have 4MB fastram in 8 chips which makes the zips have the size 1Mx4, thus you wont be able add more memory using your 256kx4 zips

.

If you look the printing on the motherboard, you will see that each zip-socket is labeled - from U850 to U881. These 32 zip-sockets are divided in four banks of 8 zip-sockets each and when expanding the memory you must fill a bank completely. U850 to U857 is the first bank, U858 to U865 is the second bank, U866 to 873 is the third bank and U874 to 881 is the fourth bank.

Also stumbled upon the A3000 manual, it has lots of info and is probably more accurate than me :=).

/Patrik

Thanks for the info, Patrik!
Can't use the zips I bought if I remove the ones I have in now?

After a cup of nice warm coffee here I'll study the manual

alexh · 06 February 2005, 17:31

1Mb x 4 = 1024 Kbits * 4 = 512 Kbytes

Thus 8 * 512Kbytes = 4Mbytes.

That is what you have at the moment.

-------------------------------------------------------------

256K x 4 = 256 Kbits * 4 = 128 Kbytes

Thus 16 * 128Kbytes = 2Mbytes.

I think you could use your new chips ( with a Jumper change) but you would loose 2Mbyte of FastRam. Even with 32 chips you could only equal what you already had.

If you can take the chips you got back and get 1Mbx4 ones. Or an Amifast Zip2Simm converter.

06 February 2005, 11:22	#1
AMIGAZ Amiga-Mad Join Date: Oct 2004 Location: Sweden Age: 46 Posts: 1,286	upgrading fast ram in an A3000 My current memory setup in my A3000 is 2mb chip and 4mb fast and I've bought 16 pcs of 256k x 4 page mode 20 pin zip modules that I want to expand my fast ram with but the problem is that I don't know what type I have in now (have 8 modules attached) and if I can mix the ones I bought with the ones I have and how to arrange them in the sockets (just fill all sockets up) I've attached some pics of how they are arranged now and the numbers can be seen on them. Hope someone can help me, don't want to post at Amiga.org yet because it sometimes seem that they ingnore people with less than 500 posts

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Use of 4MB PCMCIA Fast Flash Memory as Fast RAM in A1200	nkarytia	support.Hardware	10	16 September 2011 13:37
[SAS/C] Making malloc() allocate in fast RAM instead of chip RAM?	8bitbubsy	Coders. General	3	07 August 2011 07:06
Upgrading the Ram on a standard 4000D?	davideo	support.Hardware	7	06 May 2008 01:41
32-bit FAST RAM vs. ZII FAST RAM	polbit	support.Hardware	16	28 January 2007 20:16
A3000 - no fast RAM ;_;	LocalH	support.Hardware	3	05 September 2004 14:22

06 February 2005, 15:31	#2
patrik Registered User Join Date: Jan 2005 Location: Umeå Age: 43 Posts: 922	@AMIGAZ: You can only have one size of zips in the A3000 - either 256kx4 or 1Mx4. You set the size of the used zips with the J852 jumper which is located between the videoslot portion going to the daughterboard and the Super DMAC. Currently you have 4MB fastram in 8 chips which makes the zips have the size 1Mx4, thus you wont be able add more memory using your 256kx4 zips . If you look the printing on the motherboard, you will see that each zip-socket is labeled - from U850 to U881. These 32 zip-sockets are divided in four banks of 8 zip-sockets each and when expanding the memory you must fill a bank completely. U850 to U857 is the first bank, U858 to U865 is the second bank, U866 to 873 is the third bank and U874 to 881 is the fourth bank. Also stumbled upon the A3000 manual, it has lots of info and is probably more accurate than me :=). /Patrik

06 February 2005, 17:31	#4
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,337	1Mb x 4 = 1024 Kbits * 4 = 512 Kbytes Thus 8 * 512Kbytes = 4Mbytes. That is what you have at the moment. ------------------------------------------------------------- 256K x 4 = 256 Kbits * 4 = 128 Kbytes Thus 16 * 128Kbytes = 2Mbytes. I think you could use your new chips ( with a Jumper change) but you would loose 2Mbyte of FastRam. Even with 32 chips you could only equal what you already had. If you can take the chips you got back and get 1Mbx4 ones. Or an Amifast Zip2Simm converter.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)