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· Tech Notes & Util.
#Peeking LCD memory
5 messages in this thread
Characters are displayed in a matrix of 8 rows X 6 cols. The standard printable
ASCII characters (32(blank)-127(DEL)) use only 7 rows X 5 cols (the last row &
col is cleared). The pixel map for these starts at ROM adrs 30481 (the entry
for "blank"). Each standard character has a 5-byte entry here, the 1st byte
describing the 1st col, & so on. In a byte, the sign bit is set if the last row
in the column is to be set, & so on. (E.g., "A" is described by 124, 18, 17, 18
124).
Following this table is a similar table for the "graphic" chars (128-255).
Graphic chars use the full 8 rows X 6 cols, so each entry in THIS table is 6
bytes long. The entry for ASCII 128 starts at 30961, and so on until 255's
entry at 31723.
Sorry you asked?! – tim
Tim,
Now my only question is which byte has the sign bit turned on if the
last row/column is on? The first, last or all of them. I'll write the program
to test the first and see what happens. Thanks.
Bill.
Tim,
Now my only question is which byte has the sign bit turned on if the
last row/column is on? The first, last or all of them. I'll write the program
to test the first and see what happens. Thanks.
Bill.
Ah! Thanks! Where were you when I asked the same question two week ago? (Do I
have bad breath? Have I been offensive? Have the angels turned their backs on
me? Am I paranoid?)
Ah! Thanks! Where were you when I asked the same question two week ago? (Do I
have bad breath? Have I been offensive? Have the angels turned their backs on
me? Am I paranoid?)