Atari 400 Technical Reference Manual page 209

B46 TMPROW* [0288,IJ and TMPCOL* [0289,2J -- Temporary storage
B47 TMPLBT* [02A1, 1J -- Temporary storage
B48 SUBTMP* [029E,1J -- Temporary storage
B49 TINDEX* [0293, 1J -- Split screen text window screen mode
TINDEX is the split-screen text window
e~uivalent
of DINDEX and is
always equal to zero when SWPFLG is
e~ual
to zero (see 844).
B50 BITMSK* [006E,IJ Temporary storage
B51 LINBUF* [0247,40J
Physical line buffer
LIN8UF is used to temporarily buffer one physical line of text
when the Screen Editor is moving screen data.
B52 TXTMSC [0294,2] -- Split screen memory address
TXTMSC is the split-screen text window version of SAVMSC (836).
See 844 for more information.
B53 TXTOLD* [0296,6J -- Split screen cursor data
See B44 for more information.
Internal Character Code Conversion
Two
variables are used to retain the current character being
processed (for both reading and writing); ATACHR contains the
value passed to or from CIQ, and CHAR contains the internal code
corresponding to the value in ATACHR. Because the hardware does
not interpret ATASCII characters directly, the transformations
shown below are applied to all text data read and written:
224
ATASCII
CODE
00-IF
20-3F
40-5F
60-7F
BO-9F
INTERNAL
CODE
40-5F
00-IF
20-3F
60-7F
CO-OF
OPERATING SYSTEM C016555 -- Appendix L