Commodore Plus 4 - Page 215

Graphics Programming in BASIC 80S
The value in the table for the character base address (characters) tells you
where to copy the ROM patterns to if you want to use some of the standard
characters. If you want to know where a specific character's patterns begin, take
its screen code (see Appendix E), multiplied by 8, and add it to the character base
address. To copy the pattern of a specific character in the character ROM, use the
following:
FOR 1=0 TO 7
POKE oharaoters+new code*8+I,PEEK(ii0M+oid code*8+I)
1TEXTI
where characters is the new character set base address, new code is the new screen
code for the character, ROM is the old- base address (53248 for an upper
case/graphic character, or 54272 for an upper/lower case character), and old
code is the original screen code for the character.
High-Resolution Custom Characters Example Program
In this example, type the small letters inside the quotes without shifting, and type
the capital letters inside the quotes shifted.
10 POKE 1177,62
SO FORI=0TO1023
30 P0KE8192+I,PEEK(54272+I)
40 1TEXT
50 P0KE1177,63
60 P0KE65299,(PEEK(65299)AND3)0R32
70 P0KE65298,PEEK(65298)A]H)251
80 P0KE1351.128
90 F0RI=0T07:READA:P0KE8192+IrA.:NEXT
100 PRIHT'The Temperature is 25@C"
110 PRINT"Hit a key to restore standard characters"
120 GETKEYAl
130 P0KE65299,(PEEK(65299)AlirD3)0R208
140 P0KE65298,PEEK(65298)0R4
150 P0KE1351.0
160 END
170 DATA24,36,36,24,0,0,0,0
Line-by-Line Explanation
10 The BASIC function PEEK is altered to look at ROM.