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1541 emulates by sd card

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Not nice enough, though  :(.

Attached is the schematic that I use to connect the SD card. The cable to the core goes like this:

K1-1: J7 RC

K1-2: J7 SC

K1-3: J7 SO

K2-4: J7 Vd

K2-6: J7 Vs

K4-7: J6 SI

(I am counting the pin numbers of the SD card as shown in the SD footprint PNG).

When I load the "dir_browser" example application, all I get is error code 01, which apparently means "0x01  Error during SD Card Access (SDCARD_SectorRead or SDCARD_SectorWrite)".

Although I am using 1N4148 diodes, the voltage drop across these seems to be considerably smaller than 0.7V each - I measure around 4.2V at VDD33 of the SD card... which might be related to the low current that the SD card needs. Anyway, I am a little afraid of killing my SD card. So far it is still working...

So, what could be wrong here? TK, can you confirm that this is the schematic that you use?

Thanks, ilmenator



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Basically I'm using the same circuit like Ulrich Radig, but for the 3.3V supply I'm using the LM317 based VR circuit of MBHP_USB

Depending on the weather I will find some time this WE to draw the circuit (hope for a bad weather! ;))

Best Regards, Thorsten.

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I can confirm that the above schematic is actually correct, my card seems to be working now. The problem apparently was that I am using the floppy cable connector as shown below - you have to be careful not to push the card too far into the connector, otherwise contact will not be made. It's a bit fragile, but for a first try okay - if you know about the difficulties, that is  ;).

Note that only two of the diodes are actually used - the other two are bridged on the backside, so the circuit is exactly as shown in the schematic above. Also, when the card is correctly inserted, the voltage is 3.6V which apparently works without damaging the card.

Btw, the card is partitioned to 1GB so that FAT16 can be used (the full 4GB can not be used).

Best regards, ilmenator



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