Vic20 - Turtle Basic
Op Internet heb ik alleen deze gegevens kunnen vinden:
Turtle BASIC [VIC] (1985, Craig Bruce)
Adds 51 turtle graphics, sound, I/O and programming commands.
Daarom heb ik Craig Bruce himself geschreven en hij schreef de commando's voor me op:
GRAPHIC initializes the screen for either text or hi-res graphics.
OLD is the opposite of NEW; it brings back the old program if memory hasn't
TURN, TURNTO, PEN, DRAW, MOVE, MOVETO, and REPEAT are turtle-graphics
PEN selects the pixel-plotting mode.
POINT, DRAW BOX draw graphics at absolute positions.
KILL disables Turtle Basic and KILL SYS probably removes Turtle BASIC from
WRITE writes characters on the hi-res screen.
DOKE is a 16-bit poke.
SCREEN selects the memory address of the text screen.Â Turtle Basic
reserves all of 4096 to 8191 as graphic memory, so the screen can go
anywhere in there.
RELOC I'm not sure about; it might move raw memory contents around.
FILL fills raw memory.
RTIME I'm not sure what it does.
BASE changes the character-set base for text mode and maybe also for the
PAUSE pauses for a duration.
POP removes the last GOSUB or ALL of them.
COLOR selects the colors; you only need to get as many values as you need;
the cursor color is also the graphic-plotting color.
MERGE merges another BASIC program into your current program.Â I'm not sure
if it untangles overlapping or out-of-order line numbers.
CHAR I'm not sure about.
TAKE might be like GET except giving a PETSCII code.
SOUND sets the sound values; only give as many values as you want.
VOL sets the volume.
PUT is probably like a POKE to screen and color memory.Â Location 0 is
probably the start of the screen.
PLACE stores a string of hexadecimal-encoded bytes into memory.
CLS clears the screen and presumably the graphic screen if you are in hi-res
ACCEPT is probably like an INPUT that reads an entire line including commas,
RESET resets the computer.
GRAB function is like a PEEK to screen memory, GRAB COLOR to color memory.Â
The location probably starts from 0.
RDOT function reads the content of a graphic pixel.
PLR$ function, I don't know.
DEEK function is a 16-bit peek.
JOY function reads a joystick.
RUN looks like it is extended to properly run a chained program.
POKE accepts multiple values to poke to sequential memory locations.
POS positions to cursor on the screen and optionally prints stuff.
PEEK$ function is kile peek but maybe returns hexadecimal.
ASC function is probably fixed not to blow up on an empty string.
PEN function returns the current pixel-plotting mode.
RESTORE accepts a line number.
Eigenlijk was ik nieuwsgierig naar de turtle graphics, maar die heb ik (nog) niet tevoorschijn kunnen halen. Iemand een idee? Misschien kan het alleen in / via een programma, bedenk ik nu.