I think after much reading I know the sequence.

Note in DaveF link above there is a V9 version of the firmware.

So first you download v9-SD Tools.zip

Then unzip that and get :
DiskImager    Application  88 KB    and      S2S4S5S7-img   Disk Image File  512,000 KB

Then - using the Diskimager program -  you put the S2S4S5S7-img file onto your SD Card. Then load the SD card software into your miner on a startup.

With luck you should end up with a miner that will get into the normal miner program.

Then using the update function from within the miner you update with Antminer-V9-20180312-600M.tar  which you should have downloaded to your computer previously.

The only file that ever gets put onto the SD card is the S2S4S5S7-img   Disk Image File

I would feel better if the name of this file included V9 but the title does say v9-SD Tools.zip

The main software ( Antminer-V9-20180312-600M.tar ) gets updated from within your computer NOT the SD Card.

At this point I am not ready to try this so cannot say it works. Use at your own risk!

Comments please if you think this is the correct method or is a wrong method.

There seems to be very little info available on how to use the SD Card. Maybe they think it is so easy us newbies should already know.