Simple Electon MMC Interface

[hoglet]

An older 2Gb (also with adapter) gives me the error "Card format?". I tried the debug version, the output is in the image.

I've finally found time to try the card that you sent me, and I think managed to reproduce the error.

The problem is caused by the card being formatted as FAT16:

Code: Select all

$ sudo fdisk -l /dev/sdc
Disk /dev/sdc: 1.9 GiB, 2002780160 bytes, 3911680 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x4ed703c6

Device     Boot Start     End Sectors  Size Id Type
/dev/sdc1         129 3911679 3911551  1.9G  6 FAT16

MMFSv2 (which you were using) only supports FAT32, because it includes code to follow FAT chains, and making that generic would take a lot of space.

MMFSv1 supports both FAT16 and FAT32, and this card seems to work fine.

Dave

[pmul128]

Doh'
Should have spotted that! Thanks for taking the time, relief to know it's not a bug in MMFS2.

[Bitstik]

Hi,
I’m just about to try this on one of my Plus 1s-

I’m going to try to connect a cable to the underside so that I can leave the sd connected internally.

On trying to work out which pins to solder to I note that there is a solder bridge on my circuit board - not done by me.
Please can anyone tell me if I should leave this as it is or try to remove the solder bridge.
Many thanks

[Bitstik]

Looking at the manual it seems even pins 2-24 are tied to ground anyway so this might not be an issue

[Bitstik]

Soldering done to underside- I’ve followed the wiring colours from the first page.

[Bitstik]

And it works…
Had to make up a printer port cable to assist in debugging…
Then I realised I’d forgotten to RTFM and my card? error was as a result of me using sideways ram which was write protected…
Loaded vanilla electron printer port version and all good.
Thanks all for developing this.

[Ukwebb]

I've just tried doing this to my Slogger ROMbox Plus and cant get it work beyond "Card?"
Using the same MMFS (v1.55 Jan24) rom, same wiring, same SD reader and card on my Acorn Plus 1 it works fine
which points at either a problem with the ROMbox+ or a simple incompatibility

So first things - Has anyone got an SD reader connected to their ROMbox+ like this?
or does anyone have an idea where to start diagnosing?

( I've also not tried the printer port on a printer yet )

I wonder if SirMorris got it working 7 years ago?

[rharper]

I have tried MMFSv2 Electron printer port version (1.55) connected as my modified Plus 1's except powering from elsewhere but could not get it to work.
I haven't tried looking at the schematics to see if the pins used for the MMC card are connected differently.
Ray

[vanekp]

MMFSv2 requires a SD card formatted at Fat32 and then normal disc imaged on it not a BEEB.MMB with disc images in it.

[Ukwebb]

except powering from elsewhere

Using a common ground wire .tied to both the elks and your 'elsewhere' PSU ?

[Ukwebb]

For anyone tying to do this on a slogger romboxplus, be aware of this

viewtopic.php?p=424127

[rharper]

except powering from elsewhere

Using a common ground wire .tied to both the elks and your 'elsewhere' PSU ?

Power was from a User Port - UPURS or AP5.
Ray