itty-bitty-vtty/vt100.ctrl.S
Kelvin Sherlock 6e0de284e0 more vt100 code
to handle DECAWM mode, bit 7 of x ($80 + 79) indicates a wrap is imminent, as opposed to just being in column 79. backspace, etc will drop back to column 78 (based on testing).
2021-09-17 19:50:56 -04:00

119 lines
1.3 KiB
ArmAsm

lst off
cas se
rel
xc
xc
use vt.equ
*control chars
ext draw_char,update_cursor
control ent
asl
tax
jmp (:table,x)
:table
dw :rts ; ^@
dw :rts ; ^A
dw :rts ; ^B
dw :rts ; ^C
dw :rts ; ^D
dw enq ; ^E
dw :rts ; ^F
dw bel ; ^G
dw bs ; ^H
dw tab ; ^I
dw lf ; ^J
dw vt ; ^K
dw ff ; ^L
dw cr ; ^M
dw so ; ^N
dw si ; ^O
dw :rts ; ^P
dw xon ; ^Q
dw :rts ; ^R
dw xoff ; ^S
dw :rts ; ^T
dw :rts ; ^U
dw :rts ; ^V
dw :rts ; ^W
dw can ; ^X
dw :rts ; ^Y
dw sub ; ^Z
dw esc ; ^[
dw :rts ; ^\
dw :rts ; ^]
dw :rts ; ^^
dw :rts ; ^_
:rts rts
enq
* send answer back message.
* answer back message is a user-controllable string of text sent as-is
* (with no specific terminator character)
rts
bel
* todo - trigger nice ensoniq beep.
rts
bs
* backspace, no wrap
lda x
beq :rts
and #$7f
dec
sta x
jmp update_cursor
:rts rts
tab
* go to next tab stop
* tab at 80 does not reset overflow.
rts
lf
vt
ff
* vt and ff interpreted as lf
* LNM: also do cr.
bit LNM
bpl :lnm
stz x
:lnm
lda y
cmp BM ; bottom margin
bne :iny
jmp scroll_up
:iny inc y
jmp update_cursor
cr
stz x
jmp update_cursor
so ; G1 character set
si ; G0 character set
rts
xon
xoff
* flow control...
rts
can
sub
* cancel esc sequence and display error character
stz state
rts
esc
lda #st_esc
sta state
rts