RosettaCodeData/Task/Draw-a-clock/Forth/draw-a-clock.fth

65 lines
1.8 KiB
Forth

HEX
8379 CONSTANT TICKER \ address of 1/60 second counter
CREATE PDT ( -- addr) \ bit pattern descriptors for 0..9 and colon
0038 , 444C , 5464 , 4438 , ( 0)
0010 , 3010 , 1010 , 1038 , ( 1)
0038 , 4404 , 1820 , 407C , ( 2)
007C , 0810 , 0804 , 4438 , ( 3)
0008 , 1828 , 487C , 0808 , ( 4)
007C , 4078 , 0404 , 4438 , ( 5)
0038 , 4040 , 7844 , 4438 , ( 6)
007C , 0408 , 1020 , 2020 , ( 7)
0038 , 4444 , 3844 , 4438 , ( 8)
0038 , 4444 , 3C04 , 0438 , ( 9)
0000 , 3030 , 0030 , 3000 , ( :)
: ]PDT ( 0..9 -- addr) [CHAR] 0 - 8 * PDT + ;
: BIG.TYPE ( caddr len -- )
8 0
DO
CR
2DUP BOUNDS
?DO
I C@ ]PDT J + C@ \ PDT char, byte# J
2 7 DO \ from bit# 7 to 2
DUP 1 I LSHIFT AND \ mask out each bit
IF [char] * EMIT \ if true emit a character
ELSE SPACE \ else print space
THEN
-1 +LOOP DROP
LOOP
LOOP
2DROP ;
DECIMAL
CREATE SECONDS 0 , 0 , \ 2 CELLS, holds a double integer
: SECONDS++ ( -- ) SECONDS 2@ 1 M+ SECONDS 2! ;
\ subtract old value from new value until ticker changes.
: 1/60 ( -- )
TICKER DUP @ ( -- addr value)
BEGIN
PAUSE \ *Gives time to other Forth processes while we wait
OVER @ \ read ticker addr
OVER - \ subtract from old value
UNTIL
2DROP ;
: SEXTAL ( -- ) 6 BASE ! ;
: 1SEC ( -- ) 60 0 DO 1/60 LOOP SECONDS++ ;
: ##: ( -- ) # SEXTAL # DECIMAL [CHAR] : HOLD ;
: .TIME ( d --) <# ##: ##: # # #> BIG.TYPE ;
: CLOCK ( -- )
DECIMAL \ set task's local radix
BEGIN
1SEC
0 0 AT-XY SECONDS 2@ .TIME
?TERMINAL
UNTIL
2DROP ;