I made some progress with SD Card support.
-Two new buttons SDUpload & SDPrint added
-List files on SD card and choose one from printing
-Upload current gcode to SD card and start printing
Only progress reporting during SD print is missing. (M27)
When will this appear in the beta? I’d love to try, now that the SD-Card is enabled on my makibox.
@My_Makibox this weekend I guess
Awesome! I found out about this app, purchased it, requested the SD update and you just happened to be working on it and now it’s being tested! I’d be very happy to try the beta, and to confirm that this and any future versions do work for Melzi electronics / Marlin firmware 
What is involved in ‘trying the beta’ Mathias? will you post a link or should I send a request via email?
@Jarred_Baines SD Card support was easier to implement than expected. I will post a link, probably later today. Stay tuned 
I haven’t had a chance to try the new beta yet Mathias, but when I was printing using the previous version (manually entering the M codes to get it to print from SD) I found that the speed control did not work.
How is the speed control implemented? I use pronterface when using the PC and I’ve created custom buttons to send “M220 S%%%” where S%%% is the speed override expressed as a percentage. M220 S50 brings the speed down to 50%…
In pronterface, somehow if I am printing from the SD I can still issue a M220 S%%% command and as soon as the buffer is empty (10-20 moves or so usually) the M220 code is inserted and the speed change takes effect, so I can change speed on-the-fly for tricky layers, even when SD printing.
I will test your new beta first, but I noticed in the past version this didn’t work for me, so was wondering how your speed control works? does it modify the G code which is being sent to the printer, or does it send an M220 command to the printer?
@Jarred_Baines good catch. This was a bug in the speed control. I have added M220 to the manual print queue, but I pulled from this print queue only when pause is activated.
Next beta version will include the fix.
Righto! Thanks @Mathias_Dietz 