Following a comment from Sivan, I have produced an upgraded version of the IAST or ISO 15919 keyboard. Sometimes it is useful to write Sanskrit and other Indic languages in a form that is unambiguous but can be easily read by people who know the Latin alphabet. The standard ways of doing this are with IAST or ISO 15919. The two schemes are almost identical. An example is ताण्डव which can b written as Tāṇḍava. I have produced a windows keyboard that contains the necessary diacritics (accent marks). The normal keys are assigned the same as the standard UK keyboard, only the characters accessed with the AltGr and Shift-AltGr change, as do some characters using the caps lock.
The changes to the keyboard are as follows. Firstly in the previous version I had placed the ṅ character as AltGr-n. Most other keys used the AltGr to indicate the dot underneath, and this difference was confusing. I have therefore swapped the ṅ and ṇ so that AltGr-n gives the ṇ character. Apart from anything else it makes typing Tāṇḍava a lot easier!
Also Sivan pointed out that I had missed the visarga from the keyboard. This is the h with a dot ḥ. I have placed this as AltGr-h Here is the layout of keys with AltGr (or Ctrl-Alt does the same if your keyboard doesn’t have an AltGr key)
The Shift-AltGr keys are as expected, showing the capitalised versionsof the same letters.