BBS: Inland Empire Archive
Date: 09-16-82 (06:00) Number: 298
From: RICH GELDREICH Refer#: NONE
To: ROB SMETANA @ 914/201 Recvd: NO
Subj: Text Mode Fonts Conf: (2) Quik_Bas
RS> That's one type of approach we demonstrated in an article
RS>we just sent to Cleary for QBNews. But a Clipper programmer
RS>mentioned a firm offering 4 fonts (full, I believe) at once.
RS>If true, like to know how they're doing it -- in TEXT mode.
Simple, with the VGA you can select between 256 characters
with blinking control, or 512 characters without blinking control
for each character cell on the screen. (The 7th bit of the
attribute byte in video memory controls blinking, as you probably
know.)
This is off the top of my head, but once this mode is
enabled each char/attribute in video memory works something like
this:
1st byte 2nd byte
-------- --------
First 8 bits 7 6 5 3 2 1 0
of character | | | | | | |
| | | | -------Foreground color, 3 bits
| --------Background color, 3 bits
--This is the 9th bit of the character, 1 bit
Do you see? With 512 possible characters, you could have 4
fonts of 128 characters, or 8 fonts of 64. I could give you some
more info if you want it...
Rich
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