Adding an extra ram socket to apollo 1260

[Nikolaj_sofus]

I were thinking of adding another ram socket for my apollo 1260 accelerator.

The only thing is that i'm using it in a desktop case and wondered if it would cause any trouble if i added the socket trough wires, so i could still fit it in the a1200 case.

Has anyone attempted this before?

[mfilos]

I don't think anyone tried it, but I can't see any reason not to work. Of course the wires should be kinda short to avoid noise in signals. Dunno only if you try you can know. It's a lot of trouble but if it works it should worth it

[Nikolaj_sofus]

Originally Posted by mfilos

I don't think anyone tried it, but I can't see any reason not to work. Of course the wires should be kinda short to avoid noise in signals. Dunno only if you try you can know. It's a lot of trouble but if it works it should worth it

i guess its limitted how short it can be made if you want to get it out of the way.

[8bitbubsy]

Not a good idea, the read/write timing is probably critical... And it's important to have good contact, which can be frustrating.

[Zetr0]

Hiyas Nikolaj

Originally Posted by Nikolaj_sofus

I were thinking of adding another ram socket for my apollo 1260 accelerator.

The only thing is that i'm using it in a desktop case and wondered if it would cause any trouble if i added the socket trough wires, so i could still fit it in the a1200 case.

Has anyone attempted this before?

I am afraid that by adding wires you will introduce three things... Noise Pickup, signal impedance and propagation delay.


I am not saying its impossible, but with critically timed circuits like memory managemet these things become paramount.

What is more concerning is speed of the CPU and Memory, its quite a struggle to find good memory that can keep up with 50mhz (syncronus with the CPU) and most of the times we shuffle back to half of that (asyncronus) 25mhz.


Propagation Delays

By introducing propagation delays this skew timing, imho making it difficult to even achieve operation at 25mhz.


Signal Impedence

Then we have signal impedence, - wire is a resistor, the longer the wire the greater the resistence becomes, its quite likely that you will lose signals when introducing lengths of wire.


Noise Pickup

Copper tracks can act as signal picks up, that is to say they can resonate with the exterior RF noise and collect enough energy to -

1. provide a signal burst where none should be
2. introduce enough noise to drown a signal burst

Most tight circuits that rely on clean (sharp) signals and as such have filters / decouplers to reduce the effects of external RF and hence reduce signal pickup.

By introducing lengths of wire you are creating an antenna array which converts elctromagentic radiation (external RF noise) into electrical current.

Although this will be a weak its likely to enough to scramble the circuit in places thus making it inoperable.


A While back...

I thought about adding an extra SIMM socket on wires so that I could use my Apollo 060 in my Desktop with 64MB ram. I factored that 5cm (50mm) would be the maximum I could use.. Unfortinately 5cm is not enough to make any difference and runs to high a risk of RF interference.

With that I decided that this was not going to be (atleast for me)

Theres nothing stoping you from trying, But I do insist that are very carefull with what you do, as its possible to damage the memory controller by driving it too hard.

[Cosmos]

And what do you think about this, Zetro ?

[mfilos]

@Cosmos
Hahahaha man you're an unbelievable modder! I so much love seeing your work

[Cosmos]

... more to come...

[Zetr0]

Originally Posted by Cosmos

And what do you think about this, Zetro ?

Some nice work Cosmos!

[cosmicfrog]

hehehe hardware on stilts