I believe it was for a RAM drive since there's no cache on-board, or possibly video.Just a gentle nudge on this... but maybe nobody knows!
Finally found the answer for sure in the 1400LT service manual - it's for disk cache, 128KB, DC000 - FC000. So what I need now is a disk caching utility for an 8088 CPU that can be configured to use this.
Lol! But doesn't Smartdrv require 386?
t14mem.zip
Program loads TSR's into the 128k "extra" RAM on the 1400LT, other features.