The 2013 version of my Rainbow disassembly (HTML + IDA 5 freeware source included).

https://dl.dropbox.com/u/37819653/Jan-2013_DISASSEMBLY.zip

Documented & located a bunch of internal routines, for example

$1e15 - ROM_ConsoleLev2In
$1e01 - ROM_ConsoleLev2Stat
$1e24 - ROM_ConsoleLev1In
$001e - ROM_DisableCursor
$0021 - ROM_EnableCursor
$1e49 - ROM_InitVectors
$1dfa - ROM_ReturnClock
$1ebf - ROM_SetLeds (keyboard LED positions documented)
$1ec3 - ROM_ClearLeds
$1ecc - ROM_FastVideo (with parameters!)
$1f09 - ROM_InitToNVM
$1f0c - ROM_RawKbdData
$1f23 - ROM_RomVersion
$1f66 - ROM_ChangeVectorMap
$1fc2 - ROM_RingBell
$1fc8 - ROM_GetSet7or8

(just search for :1DBA in the HTML output)