Target coordinates are normally supplied to the telescope computer by means of an observation catalogue. This must be typed in directly through the user interface or using an editor. If you have an extensive catalogue, this is best done in the afternoon before you start observing. Catalogues can of course be saved to disc, so they are available from night to night, but will normally be deleted at the end of an observing run. The telescope computer now has a tape drive and files can be transferred from the VAX 8300 on a scratch tape. This is a clumsy procedure and advance notice is necessary.
Positions of guide stars selected in advance of the observing run should be entered in the catalogue in the normal way.