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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: orange on May 05, 2008, 01:54:16 PM

Title: is this ZIP RAM?
Post by: orange on May 05, 2008, 01:54:16 PM
I found an old GFX card (http://www.fileden.com/files/2006/9/12/214909/Amiga/ZIP_IMG_1240-up.jpg) and noticed it has chips that look like ZIP RAM but are longer. Can they be used somehow as ZIP inside for eg. Alpha Power?
Title: Re: is this ZIP RAM?
Post by: Plaz on May 05, 2008, 03:09:00 PM
They are zip packages, but unless they are pin for pin matches to the card you want to use them in, they's no way they will works without something like an adapter.

Plaz
Title: Re: is this ZIP RAM?
Post by: Zac67 on May 05, 2008, 06:13:22 PM
That's (probably) ZIP packaged VRAM - you'll need ZIP packaged DRAM of the 4x256K or 4x1M flavor.
Title: Re: is this ZIP RAM?
Post by: CLS2086 on May 05, 2008, 07:09:33 PM
As it is a nice an old Cirrus, it may be DRAM.
But watch out the references !!
If you plain to get one day a bridgeboard, keep the card ;-)
Title: Re: is this ZIP RAM?
Post by: rkauer on May 05, 2008, 08:54:08 PM
 What exactly is the ZIP chips name? With the "name" (code) we can dig the chip type.
Title: Re: is this ZIP RAM?
Post by: Zac67 on May 05, 2008, 09:27:50 PM
I'm not entirely sure this is DRAM - the lengthy package looks strange.
Can't find any decent details on the GD5422 though, only it's 32 bit memory interface and 1 MB max - 4x256K chips for sure.
Title: Re: is this ZIP RAM?
Post by: rkauer on May 05, 2008, 10:26:40 PM
Quote

Zac67 wrote:
I'm not entirely sure this is DRAM - the lengthy package looks strange.
Can't find any decent details on the GD5422 though, only it's 32 bit memory interface and 1 MB max - 4x256K chips for sure.


 To achieve 1Mb you need 8 chips! 4bits x 256kb = 128kb.
Title: Re: is this ZIP RAM?
Post by: Zac67 on May 06, 2008, 07:23:34 AM
8x 4x256K = 32x256K == 8x1M  ;-)
Title: Re: is this ZIP RAM?
Post by: countzero on May 06, 2008, 08:09:20 AM
the ram in the pic is 28 pin if I counted right. alfa data and most amiga stuff uses 20 pin ram AFAIR.
Title: Re: is this ZIP RAM?
Post by: rkauer on May 06, 2008, 08:32:01 PM
Quote

Zac67 wrote:
8x 4x256K = 32x256K == 8x1M  ;-)


 Nope.

 8x 1/2byte (4bit) x 256k (1/4 Mb) == 1Mb
Title: Re: is this ZIP RAM?
Post by: Zac67 on May 07, 2008, 07:35:25 AM
Sigh...

1 chip is 4 bit x 256K.
2 chips in parallel are 8 bit x 256K = 256KB.
8 chips are 4x2 chips, so either 8x (4x256K) or - one this card - (8x4)x256K - same amount of memory: 1M bytes or 256K 32bit words.
Title: Re: is this ZIP RAM?
Post by: orange on May 07, 2008, 04:07:15 PM
the chips have 28 pins
here is whats written on them:
D42274V-12
Title: Re: is this ZIP RAM?
Post by: Zac67 on May 07, 2008, 06:34:32 PM
Well, I told you it's VRAM (http://www.xs4all.nl/~ganswijk/chipdir/n/42.htm)... ;-)
(hey, my middle name is 'smart ass' :-D)