Welcome, Guest. Please login or register.
Forums
« previous next »
Pages: [1]   Go Down

Author Topic: A2091 Ram Capacity??  (Read 1040 times)

Description:

0 Members and 1 Guest are viewing this topic.

Offline DiskChrisTopic starter

  • Full Member
  • ***
  • Join Date: Jul 2012
  • Posts: 109
    • Show only replies by DiskChris
A2091 Ram Capacity??
« on: August 14, 2014, 09:23:32 PM »
I'm looking to put some ram on my a2091, which according to amigaresource would be 4x256k dip. However, the card has 16 sockets and a max of 2 MB...Wouldn't that be 4 MB of ram if each chip was 256k??
Logged
 

Offline Oldsmobile_Mike

Re: A2091 Ram Capacity??
« Reply #1 on: August 14, 2014, 09:48:58 PM »
Has to do with some obscure and long-forgotten (except by some people on this board) conversion, kilobit vs kilobyte, etc.  I honestly don't remember anymore!  But the maximum ram capacity of that board when fully loaded is 2MB.  Sorry!  You might try adding a 32-bit accelerator, or a Zorro-II memory card, or one of those Kipper2K cards that fits underneath the processor, etc., if you want more.  :)
Logged
Amiga 500: 2MB Chip|16MB Fast|30MHz 68030+68882|3.9|Indivision ECS|GVP A500HD+|Mechware card reader + 8GB CF|Cocolino|SCSI DVD-RAM
Amiga 2000: 2MB Chip|136MB Fast|50MHz 68060|3.9|Indivision ECS + GVP Spectrum|Mechware card reader + 8GB CF|AD516|X-Surf 100|RapidRoad|Cocolino|SCSI CD-RW
 Amiga videos and other misc. stuff at https://www.youtube.com/CompTechMike/videos
 

Offline DiskChrisTopic starter

  • Full Member
  • ***
  • Join Date: Jul 2012
  • Posts: 109
    • Show only replies by DiskChris
Re: A2091 Ram Capacity??
« Reply #2 on: August 14, 2014, 10:47:47 PM »
Ah yes that makes sense....Can you mix manufactors and speeds? I'm kinda finding a few here and a few there....
Logged
 

Offline aggro_mix

  • Full Member
  • ***
  • Join Date: May 2004
  • Posts: 150
    • Show only replies by aggro_mix
Re: A2091 Ram Capacity??
« Reply #3 on: August 14, 2014, 10:52:22 PM »
Quote from: DiskChris;770909
I'm looking to put some ram on my a2091, which according to amigaresource would be 4x256k dip. However, the card has 16 sockets and a max of 2 MB...Wouldn't that be 4 MB of ram if each chip was 256k??


The chips are 256 kilobits, 4 bits wide. 1 byte = 8 bits so you'll need two chips to give 256 kilobytes.

Zorro II memory is 16 bits wide which means you'll have to add 4 chips in parallel (as they are 4 bits wide) 4x256x4= 256x16 = 512x8 (512 kiloBytes)
Logged
 

Offline DiskChrisTopic starter

  • Full Member
  • ***
  • Join Date: Jul 2012
  • Posts: 109
    • Show only replies by DiskChris
Re: A2091 Ram Capacity??
« Reply #4 on: August 14, 2014, 10:58:09 PM »
Yeah I was thinking in bytes not bits....And I managed to find some which should work, but I can only get 5...Would I be able to get different manufactors/speeds in the future assuming they were 4x256k and at least 120ns??
Logged
 

Offline Plaz

Re: A2091 Ram Capacity??
« Reply #5 on: August 15, 2014, 02:11:45 AM »
Quote from: DiskChris;770921
.Would I be able to get different manufactors/speeds in the future assuming they were 4x256k and at least 120ns??


It's possible to mix chips. I've used a few 2091's over the years and used anywhere from 80-120ns chips from different manufactures. Do some home work though and make sure pinouts and other specs match up as not to hurt your card or other chips.

Plaz
Logged
 
Pages: [1]   Go Up
« previous next »