SD Mapper Megaram will only play 64K games and smaller!

Master (195)

06-06-2023, 06:28

I have one of the my friends who owns MSX2 Alalmiah 350AX II and have SD Mapper Megaram, he couldn't initially make it run but then I help him a little bit and we get it to run and we managed to run games that are 64K and smaller using SofaRun but it won't run anything higher (128K, 256K, or 512K).

I tried to search for similar topics regarding the SD Mapper but didn't find anything that could help.

If anyone could help or give us a hint that would be appreciated.

By mars2000you

Enlighted (6565)

06-06-2023, 17:13

Do you have tried with the machine booted in European mode?

By alali.ahmed.t

Master (195)

07-06-2023, 02:13

mars2000you wrote:

Do you have tried with the machine booted in European mode?

Yeah, that's how we got it to work on 32K and 16K games. We used CTRL to be able to access but it won't run games at 128K or higher that needs a mapper!

By st1mpy

Paladin (947)

07-06-2023, 02:42

So, do you set the sd mapper to megaram mode for those megaroms (128k+ roms)?
And which megaram loading tool do you use to run the megaroms?

By alali.ahmed.t

Master (195)

07-06-2023, 06:45

st1mpy wrote:

So, do you set the sd mapper to megaram mode for those megaroms (128k+ roms)?
And which megaram loading tool do you use to run the megaroms?

I tried the switches in all directions written on the SD Mapper manual. both to the right, then the first to the left and the one by the corner to the right. both same results.

Here is what we got when we ran MSX MEM. I don't see any RAMs on his cartridge which is wierd !!! I am not sure if that's normal, but that's probably why it doesn't run any game that is more than 32K !!

By digital8

Supporter (13)

07-06-2023, 13:39

What kind of Mapper are u using.?

This is what my brothers Memory Mapper SD 512kb looks like.

I myself have a Memory Mapper SD 512kb v2 and that one uses different software, so make sure you have the right software on it.

Also try using a different test utility like Test Map.

https://www.retropix.com.br/lista-de-ferramentas-para-testar-o-hardware-do-msx/

By alali.ahmed.t

Master (195)

07-06-2023, 18:12

digital8 wrote:

What kind of Mapper are u using.?

This is what my brothers Memory Mapper SD 512kb looks like.

I myself have a Memory Mapper SD 512kb v2 and that one uses different software, so make sure you have the right software on it.

Also try using a different test utility like Test Map.

https://www.retropix.com.br/lista-de-ferramentas-para-testar-o-hardware-do-msx/

It has only one SD slot.

We tried another Test Ram, it only reads the machine but no the cartridge.

By st1mpy

Paladin (947)

07-06-2023, 19:18

Have you tried cleaning the cartridge?

By alali.ahmed.t

Master (195)

08-06-2023, 02:01

st1mpy wrote:

Have you tried cleaning the cartridge?

That didn't work.

What is the reason that prevents the RAM of the cartridge to be detected?!

By Pentarou

Hero (563)

08-06-2023, 12:43

A problem in the computer Subslot or some defect in the CART.
Try the cart in another computer, and if it still doesn't work it could be a defective RAM IC, a defective CPLD or bad soldering on RAM, CPLD, Switches.

By alali.ahmed.t

Master (195)

16-06-2023, 19:59

Pentarou wrote:

Thank you for your input. At the moment my friend only have access to Arabic MSX machines AX170, AX200, AX350 and AX370. I will have send him a chip for the AX370 because it is the easiest to upgrade/downgrade into another MSX.