SD MAPPER/MEGARAM 512KB on MSX Sakhr AX170

By bcastroalves

Supporter (3)

bcastroalves's picture

15-05-2022, 14:11

Hi everyone!
I recently purchased an SD MAPPER MEGARAM 512KB., but I couldn't get it to work on my MSX Sakhr AX170. For some reason it doesn't load MSX-DOS, it just enters Disk BASIC, where I can use fdisk, format the SD cards, test the reading...
I've used different SD cards, I've used files and even images (*.img ) different and did not work. Tried all possible switch combinations (ON/OFF and MR/MP).
When turning on the Sakhr AX170, I hold the "Ctrl" key to enter international mode, but even this way, it's not working. Entering normal mode (from the Arabic menu) doesn't work either. And finally, using the "CALL SYSTEM" command just restarts Disk BASIC. Does anyone have any idea what else I can try to do to make it work? I'm about to buy another MSX to make this SD Mapper work.

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By sdsnatcher73

Prophet (3217)

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16-05-2022, 07:05

What SD card are yyou using? The SD mapper can be quite picky (detection during boot and being able to run fdisk are unfortunately not enough to say the card is compatible in my experience). The card should be 4GB or less I have been told.

By bcastroalves

Supporter (3)

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21-05-2022, 03:04

I used one from Sandisk 4GB, one from PQi 2GB and another 4GB from Toshiba. I can do the read test with everyone in Disk BASIC and even format and see the partitions.
But I will test with more SD cards.

By sdsnatcher73

Prophet (3217)

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21-05-2022, 05:45

Then it seems indeed the firmware is causing the issue with booting DOS.

By sdsnatcher73

Prophet (3217)

sdsnatcher73's picture

21-05-2022, 06:51

Hmm, then again I tried MFR on AX170 in openMSX and it boots into Nextor (directly after the boot logo). It's possible the MFR detects and skips the firmware though.

By sdsnatcher73

Prophet (3217)

sdsnatcher73's picture

21-05-2022, 07:03

Tried with Carnivore2 and AX170 in openMSX. You need to boot the MSX with Ctrl and 1 key pressed. Then with _FDISK you can create a 16MB FAT12 partition. If you put MSXDOS.SYS and COMMAND.COM on the partition and boot again with Ctrl and 1 key pressed what happens?

By gdx

Enlighted (5485)

gdx's picture

21-05-2022, 09:19

If your interface use Nextor, it should be works for you because it works for this guy:
https://www.msx.org/forum/msx-talk/general-discussion/msx-do...

I tested on emulator (Nextor 2.10 + driver 0.1.5 for OpenMSX IDE) and it works even without press CTRL during the start up. So the AX170 firmware doesn't interfere with Nextor.

By bcastroalves

Supporter (3)

bcastroalves's picture

22-05-2022, 13:51

That way it starts MSX-DOS 1, I used version 1.8 (Commmand 1.21 - Ted Chary). But I couldn't use commands like cd, change drive, etc.

By gdx

Enlighted (5485)

gdx's picture

22-05-2022, 14:43

The goal is to check if your computer is working properly. No need for commands like cd, change drive, etc to do it.