SDCard adapter with eMMC - does not work

sander76 · Mar 8th 2022

Hi,

in my quest for a hardware based, recent Amiga that works (see my other threads...) I was busy with my Chaco V2 + MinimigAGA and when encountering some SD Card issues figured: why not order some eMMC memory, a micro SD card adapter and use that ? It has more wear leveling, so ideally better for long duration use than any regular SD card, while maintaining compatibility to the SD card SPI interface.

I have this: a (ordered from antratek nl) 64 GB eMMC module and a eMMC module reader to micro SD card adapter, in combination with (any ol') micro SD to SD Card adapter.

After formatting to FAT32 on a Linux PC, which just recognizes the combination as any SD card, and when then inserting the card combination into the Chaco V2, it gets stuck on "initializing SD Card". Not even getting to the menu. So something funny is going on, but what ?

If I can create more debug logging, I would - just tell me what you need. Here is at least what Linux shows for this combination, and as comparison what a regular SD card shows, delta being the 2*4MB mmcblk0boot# on the eMMC:

SD Card 32 GB:

mmc0: new ultra high speed SDR104 SDHC card at address 0007

mmcblk0: mmc0:0007 SD32G 29.3 GiB

mmcblk0: p1

eMMC:

mmc0: new high speed MMC card at address 0001

mcblk0: mmc0:0001 CJTD4R 58.2 GiB

mmcblk0boot0: mmc0:0001 CJTD4R partition 1 4.00 MiB

mmcblk0boot1: mmc0:0001 CJTD4R partition 2 4.00 MiB

mmcblk0: p1

Thanks !

Sander

Tobias · Mar 8th 2022

Quote

64 GB eMMC module and a eMMC module reader to micro SD card adapter, in combination with (any ol') micro SD to SD Card adapter.

To be honest, i am not surprised that such a contraption does not work. - It could be a power issue, or SPI simply doesnt work with this. I don't think we can do anything about it. You could try if it works in other cores, if it does then at least we can tell its a software or core issue.