View Full Version : GVP IMPACT Series II A500-HD+ questions

29th June 2012, 07:07
Hi to all :)

I have bought one GVP IMPACT Series II A500-HD+ but I want to fully populated to 8MB.

As I can see here http://amiga.resource.cx/exp/impact500mk2 it uses 30 pin SIMMs modules but......

Only accept 120ns SIMMs? 70ns or 80ns modules can be used?


29th June 2012, 08:58

there should be no problem, if the ram is faster than 120ns! :)

29th June 2012, 09:29
Column Address Strobe (CAS) latency, or CL, is the delay time between the moment a memory controller tells the memory module to access a particular memory column on a RAM memory module, and the moment the data from given array location is available on the module's output pins. In general, the lower the CAS latency, the better. So anything faster then 120 ns works while any thing >120 ns is too slow to work properly

29th June 2012, 12:06
As already commented upon, faster RAM will generally work fine. There's a small catch but it isn't an issue in this case, even 70 ns will work fine (actually that's exactly what I use in my own GVP-A500HD+, 2x4 MB 70 ns SIMMs).

29th June 2012, 17:37
Hi to all,

Thanks for the useful info. :thumbsup:

Yes, I think a faster RAM will be compatible and more reliable but it's my first GVP controller I want to get all possible info.

2nd July 2012, 23:54
Dug up the manual for more specific info (I'm pretty sure it exists online too).
Relevant quotes:
1. "The RAM that should be used is 100 ns (nanosecond) or faster, page mode DRAM SIMMs."
2. "The Impact A500-HD Series II uses 1Mx8 SIMMs for all the memory settings but the eight ( 8 megabyte setting. The 8 megabyte setting uses 4Mx8 SIMMs."
3. "The SIMMs must be inserted in a specific order. They go in from the socket closest to the front, to the socket closest to the rear of the unit. (CN9 - CN12)."
So it's either none filled (0 MB option), CN9+CN10 filled (2 MB or 8 MB options) or all filled (4 MB option).

3rd July 2012, 00:57
BLTCON0 nailed it, everything you need to know about it's RAM;

30th August 2016, 12:19
The manual talks about 1Mx8 but it doesn't say you cant use 1Mx9, or it's possible to use 1Mx9?