Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Miloo on September 08, 2007, 03:33:39 PM
-
What was the original chip ram speed in desktop 4000's?
-
It probably shouldn't matter, but A1200s have 80ns Chip RAM soldered to the board. Rev. D 4000s probably do as well, so earlier revisions likely have 80ns chips on the SIMM.
-
Does the chip ram work with the fast ram? ie if you mix memory speeds they will all run at the slowest.
Seeing as 72 pin simms are cheap I want each simm on the mobo/csppc/zorro to be the same speed.
-
Don't bother. The Chip RAM is on an entirely separate bus from the Fast RAM. It probably needs to be its original speed to work right. It definitely must be a 2 meg SIMM to work right.
-
Chip RAM and onboard fast RAM requires 80ns or less, otherwise it doesn't work. Faster RAMs provide no benefit.
-
Does it HAVE to be 2mb simm for the chip ram or will a 4mb be ok?
-
IIRC any size will do as long as it is double-sided. Single-sided will only give you 1MB of Chip RAM.
--
moto
-
SamuraiCrow wrote:
Don't bother. The Chip RAM is on an entirely separate bus from the Fast RAM. It probably needs to be its original speed to work right. It definitely must be a 2 meg SIMM to work right.
WRONG!
As Brian Guralnick indicated a few months ago, you can use a 4MB or 8MB SIMM. You won't GET more than 2MB of chip but it does work with a 4MB SIMM or 8MB SIMM.
You have to flip J213 and J214 if my memory is correct.
-
J213/J214 are for selecting 2MB vs 8MB chip RAM (the 'free sex & beer' thing) - as the Great Dave himself has pointed out, the 8 MB setting will never ever work.
Have never tried it, but the 'all single sided SIMMs yield 1 MB chip, two sided 2 MB' does make a lot of sense to me...
-
on amiga.kit you can buy it.
-
Hi,
in my A4000D the 2MB Chipram PS/2 Simm was broken and I didn't get a new one.
Therefor I tested it with an 4MB PS/2 Simm (2 Chips single sided, 70ns EDO Simm) and it works!
First there was only 1MB Chipmem available. Then I switched the both Jumpers to "8M" and suddenly the whole 2MB Chipram was available!
The same PS/2 Simms (4MB s.sided EDO 70ns) are working well as onboard Fastram.
The upper 2MB of the Simm are wasted but still better then a non working A4000.
8MB Chipram are not possible, thats right for sure!
-
That's interesting. If the reports are accurate, then the 8MB jumper does actually do SOMETHING, although the Custom Chips still wouldn't know what to do with any additional memory, anyway.
So, do we need to make a pre-emptive strike and make sure this doesn't turn into another 8MB ChipRAM thread? ;-)