A4000 chipmem speed: 70ns? 80ns? or 100ns???

[keropi]

I got some replacement 2MB memory sticks for my A4000D, and they are rated 80ns. the original one on my 4000 is 70ns, I was wondering what is the real speed of A4000 chipmem... most likely 80ns right? or slower? :-?

[justthatgood]

Yeah you know it's slow....

[keropi]

yes, but how many ms ???

[Framiga]

80ns on mine (originally) swapped then with a 70 ns one.

At least on my A4000/030 the 80ns was the default one.

PS- just checked the manual... =/< 80ns

[alexh]

I would imagine that Chip RAM requires a period of no less than 140ns. Why? It has a clock rate of 7.14MHz

Hmm... maybe it has a clock rate of 14.28MHz with AGA?

Note: using slower chip-RAM you cannot use the "speedramsey" util.

[keropi]

speedramsey?
I thought this was only for the A4000T version...

[alexh]

I dont think so, but I am not 100% sure.

I thought that it was A3000(T) and A4000(T) all models

[keropi]

checked the docs again, works on any A4000 and on A3000 that have the rev.G ramsey... all A4000 have rev.G ramsey chips, according to the author.

[DamageX]

I would imagine that Chip RAM requires a period of no less than 140ns. Why? It has a clock rate of 7.14MHz
That's true for OCS/ECS. Actually it takes two cycles (~280ns) for a RAM access, one for RAS and one for CAS. AGA needs 80ns or better static-column DRAM so it can divide the 280ns into RAS+CAS+CAS, doing two reads in a row and doubling the bandwidth.

[Zac67]

Static column on PS/2? Are you sure?