I was following this topic for a while trying to figure out the MS28 read/flash. I didn't succeed at all.
But now I found a great solution which works flawlessly for me. It's from sTix at xboxhacker.
I finally got my MS28 to read and write firmware WITHOUT doing the VCC trick. (Thanks go to Textbook and Rodpad @ Xbox-Scene for helping me out). Here's what I did:
Turn off the Xbox 360 and PC.
Connect the SATA cable from the MS28 drive to the PC, and also use croc clips to be safe.
Leave a PC CD or DVD drive on one of the IDE channels
Turn on the PC and boot from floppy , but leave the 360 off.
When you get to command prompt, turn 360 on.
Type this command: mtkflash r /m /sata orig.bin and hit enter
It should display your ports. Do NOT select anything, just leave it at the "menu"
Turn off your 360.
Now, select the port the 360 was connected to, even though the 360 is now off.
It will "pause" when you select that port
I counted to ten, then turned on the 360
It started reading automatically
Thank you sTix!