Before going any further, we ought to agree on a few terms to simplify the description of the INMEMO system.

Memo File refers to the entire auxiliary data file containing all of the individual memo pads.

Memo Pad Window (or Display Window, or Memo Window) refers to the rectangular area on the screen in which the memo pad editing and display takes place. The Memo Window is defined by its 4 corners in parameters passed to INMEMO.SBR.

A Memo Pad is a single logical block of memo text associated with one primary data file record. This may include any number of Physical Memo Records, and may be smaller or larger than a Memo Window. In the picture of a screen in section 2.0, the text shown in the Memo Window makes up a single Memo Pad.

The terms Logical Memo Record and Memo Pad are equivalent.

Scrolling is the process of moving the Memo Window throughout a larger Memo Pad. The Memo Window may be scrolled both horizontally and vertically to allow editing of Memo Pads both wider and longer than the Memo Window.

Paging is equivalent to Scrolling, although it usually refers to moving the display forward or back by the size of the Memo Window (as in Next Page or Previous Page).

Absolute Pad Dimensions (or Virtual Pad Dimensions) refers to the maximum width and length allowed for a particular memo pad. This determines the limits of scrolling.

A Physical Memo Record is a single 64-byte record in the Memo File. Physical Memo Records are linked together to form Memo Pads in a fashion similar to the way physical disk blocks are linked together to form sequential files in AMOS. Note that a Physical Memo Record is actually a logical disk record in AMOS. The internal layout of a Physical Memo Record is described in Section 7.

The Memo Control Record is a special case of a Physical Memo Record, which is always the first record in a Memo File. The Memo Control Record is used to keep track of the allocated and free portions of the Memo File; it contains the master pointers to the start of the deleted record chain and the first eof-marked record.

The Invisible Header is an optional string of up to 60 characters which is stored at the beginning of a memo but that does not normally display. This header can be used to store information allowing a memo to be identified independent of any link from another file.