[A83] Special ram areas?


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[A83] Special ram areas?




Hi,

Dunno if I told it, but I'm planning to make a font app, with external font
support, if possible. If I have external fonts, I need to transfer them to a
static location in ram, like ion's 9F60 or so. Is there another such
location that won't shift through memory? How does ion do it?
Another one: The ti-font is 5 pixels wide, but bytes are 8 bytes. Do I have
to fill the rest with zeroes? Can anyone (Andy Hochhaus?) tell me what to
change if I want to make a big font? And can anyone tell the use of eea? I
don't see it. Maybe if I downloaded it, this will change.


;Start of Andy Hochhaus code:
;To enable: (or else do a B_CALL)
ld hl,fonthook
in a,(6)
ld (9b9ch),hl  ;start of font hook
ld (9b9eh),a   ;page num font hook is on
set 5,(IY+35h)  ;flag for font hook

;Then the font hook itself:
;in: a=0 if big font, a=1 if small font
;    b=ascii of char to be displayed

;out: nz if display default tios bitmap
;     z if display custom font then also
;        hl->bitmap
fonthook:
db 83h
cp 0    ;
ret nz ;don't do anything if BIG font ;here was an error he said, however,
        ;with BIG font this should be okay(?)

ld a,b
cp 2ah ;acsii of '*' 2ah
ret nz ;if any key other than '*' return
push af
push bc
ld hl,newmult
ld de,sfont_record
ld bc,8
ldir ;copy new bitmap to safe ram location
pop bc
pop af
ld hl,sfont_record ;hl->new bitmap
ret

newmult:
db 2 ;char width
db 00000000b ;bitmap right justified
db 00000000b
db 00000000b
db 00000010b
db 00000000b
db 00000000b
db 00000000b






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