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Where would the second ram module go on the digital IO board if/when required

Posted: Thu Feb 03, 2022 7:30 pm
by Spartan
Hello

I bought a MISTer kit from MISTer Addons last Feb. Great site, everything is working fine.
I ended up buying a MISTer with the digital IO board knowing I'd never connect it to an analog input TV/monitor.

Given that the upcoming PSX/Saturn cores may require two RAM modules, where exactly on the IO board would the second RAM module connect to?
For planning purposes, I want to ensure I have a compatible Digital IO board. Would the second RAM module connect to the spare GPIO header?

Forgive the blurry photo as I currently have a case on my MISTer, but I believe this is the spare GPIO header. Would the second RAM module connect here? Is there anything else I would need to check/confirm to ensure I have a compatible board for 2 RAM modules?

Re: Where would the second ram module go on the digital IO board if/when required

Posted: Thu Feb 03, 2022 7:57 pm
by Sigismond0
Plug the module in there, flip one of the switches on the DE-10, and you're set. PSX core runs on single RAM, with improvements with two sticks. Based on what we can see in the nightly builds now, single RAM for PSX is a shoe in, and the second stick will likely just be for some performance improvement. Saturn core is still far enough out that I wouldn't invest in anything this early. Just wait and see what they need.

Re: Where would the second ram module go on the digital IO board if/when required

Posted: Thu Feb 03, 2022 10:11 pm
by Spartan
Thanks for the reply, I appreciate it..
So I was correct in thinking the second RAM module would connect to the spare/unused GPIO header on the digital io board from my previous photo? In other words my board appears to be compatible?

And I think the switch you're referring to is that SW3 switch, right?
You're right though...probably not smart to invest in another RAM module until further development is completed.

Thanks again

Re: Where would the second ram module go on the digital IO board if/when required

Posted: Thu Feb 03, 2022 10:15 pm
by Sigismond0
Correct on all counts!

Re: Where would the second ram module go on the digital IO board if/when required

Posted: Fri Feb 04, 2022 3:53 am
by dalingrin
Sigismond0 wrote: Thu Feb 03, 2022 7:57 pm Plug the module in there, flip one of the switches on the DE-10, and you're set. PSX core runs on single RAM, with improvements with two sticks. Based on what we can see in the nightly builds now, single RAM for PSX is a shoe in, and the second stick will likely just be for some performance improvement. Saturn core is still far enough out that I wouldn't invest in anything this early. Just wait and see what they need.
You're not wrong but I wanted to make sure folks don't think the single SDRAM will be slow. A single SDRAM is enough to run PSX at full speed. Both single SDRAM and dual SDRAM are currently running faster than real PSX hardware. That said, dual SDRAM will probably have a higher performance ceiling. FPGAzumSpass guessed that dual SDRAM might enable a further 10% GPU performance beyond the single SDRAM.

Re: Where would the second ram module go on the digital IO board if/when required

Posted: Thu Feb 24, 2022 4:25 pm
by Dafoof
I just installed a second SDRam module, just to be future proof and avoid any potential shortage down the line (and yes I know it is not all that useful atm, and may never be ;) ). Is there a way to test that the second module is taken into account, and working? What options should be activated on the PSX core to take advantage of it (as of the 23/02/2022 build)? Thanks!

Re: Where would the second ram module go on the digital IO board if/when required

Posted: Sat Feb 26, 2022 3:37 am
by dyne
I know the top icon on the Home Screen that looks like a street light shows how much ram is installed when running one stick. Not sure if it behaves the same way with two sticks.

Re: Where would the second ram module go on the digital IO board if/when required

Posted: Mon Feb 28, 2022 10:01 am
by Dafoof
dyne wrote: Sat Feb 26, 2022 3:37 am I know the top icon on the Home Screen that looks like a street light shows how much ram is installed when running one stick. Not sure if it behaves the same way with two sticks.
No, it doesn't, unfortunately (that would be handy) -- unless it does and my module is not active... :roll:
And I'm not sure if any options are supposed to look different in the PSX core when a second RAM module is operational. If someone does know, don't hesitate to share! ;)

Re: Where would the second ram module go on the digital IO board if/when required

Posted: Fri Mar 04, 2022 12:50 am
by KnightNZ
If it's something you'd be interested in, then the current development version(s) of the Jaguar core(s) require 2 sticks. It remains to be seen if Jotego's core will do or not as afaik nothing is known about it at this stage.