'===========================================================================
' Subject: 320X400 TURTLE DRAW               Date: 05-28-96 (18:29)       
' Author:  Earl Montgomery                   Code: QB, PDS                
' Origin:  FidoNet QUIK_BAS Echo           Packet: GRAPHICS.ABC
'===========================================================================
 'Here is some code that I wrote awhile back that uses the 320x400x256
 'mode. Press "H" to get the help menu. It allows you to sketch in this
 'mode. But it does give you the basic code to do all sorts of things
 'in this mode. Enjoy.

setmode:
 'Sets SCREEN 13 to the 320X400X256 mode
 SCREEN 13: DEF SEG = &HA000
 KEY(10) ON
 ON KEY(10) GOSUB endofprogram
 OUT &H3D4, 9: OUT &H3D5, &H40: OUT &H3D4, 20: OUT &H3D5, 0: OUT &H3D4, 23
 OUT &H3D5, &HE3: OUT &H3C4, 4: OUT &H3C5, &H6
 OUT &H3C4, 2: OUT &H3C5, 15: CLS : 'rem this clears (CLS) all 4 planes
 IF flag$ = "restart" THEN GOTO loadtemp
 OUT &H3C4, 2: OUT &H3C5, 1
begin:
 position% = 15318: c = 15: plane% = 1: OUT &H3C4, 2: OUT &H3C5, 1
restart:
 flag$ = ""
 POKE position%, c
waitkey1:
 i$ = INKEY$: IF i$ = "" THEN GOTO waitkey1
 i$ = UCASE$(i$)
 keycode% = CVI(i$ + CHR$(0))
 IF keycode% = 19712 THEN GOTO moveright
 IF keycode% = 19200 THEN GOTO moveleft
 IF keycode% = 18432 THEN GOTO moveup
 IF keycode% = 20480 THEN GOTO movedown
 IF i$ = "C" THEN GOTO changecolor
 IF i$ = "H" THEN GOTO helpscreen
 IF i$ = "X" THEN GOTO clearscreen
 GOTO waitkey1
moveright:
 IF plane% = 1 THEN OUT &H3C4, 2: OUT &H3C5, 2: plane% = 2: GOTO pokescrn
 IF plane% = 2 THEN OUT &H3C4, 2: OUT &H3C5, 4: plane% = 4: GOTO pokescrn
 IF plane% = 4 THEN OUT &H3C4, 2: OUT &H3C5, 8: plane% = 8: GOTO pokescrn
 IF plane% = 8 THEN OUT &H3C4, 2: OUT &H3C5, 1: plane% = 1: position% = position% + 1
pokescrn:
 IF position% > 31999 THEN position% = 31999
 POKE position%, c
 GOTO waitkey1
moveleft:
 IF plane% = 1 THEN OUT &H3C4, 2: OUT &H3C5, 8: plane% = 8: position% = position% - 1: GOTO doit
 IF plane% = 2 THEN OUT &H3C4, 2: OUT &H3C5, 1: plane% = 1: GOTO doit
 IF plane% = 4 THEN OUT &H3C4, 2: OUT &H3C5, 2: plane% = 2: GOTO doit
 IF plane% = 8 THEN OUT &H3C4, 2: OUT &H3C5, 4: plane% = 4:
doit:
 IF position% < 0 THEN position% = 0
 POKE position%, c
 GOTO waitkey1
moveup:
 position% = position% - 80
 IF position% < 0 THEN position% = position% + 80
 POKE position%, c
 GOTO waitkey1
movedown:
 position% = position% + 80
 IF position% > 32000 THEN position% = position% - 80
 POKE position%, c
 GOTO waitkey1
changecolor:
 c = c + 1
 IF c > 255 THEN c = 0
 POKE position%, c
 GOTO waitkey1
 GOTO waitkey1
helpscreen:
 'Saving screen before switching to SCREEN 9 and the HELP MENU
 DEF SEG = &HA000
 OUT &H3CE, 4: OUT &H3CF, 0: BSAVE "temp1.bin", 0, 32000
 OUT &H3CE, 4: OUT &H3CF, 1: BSAVE "temp2.bin", 0, 32000
 OUT &H3CE, 4: OUT &H3CF, 2: BSAVE "temp3.bin", 0, 32000
 OUT &H3CE, 4: OUT &H3CF, 3: BSAVE "temp4.bin", 0, 32000
 SCREEN 9: CLS
 PRINT "Key             Function"
 PRINT "Use arrow keys to move cursor"
 PRINT "C               Changes current color"
 PRINT "F10             Exit Program "
 PRINT "H               Help (This Screen)"
waitkey2:
 i$ = INKEY$: IF i$ = "" THEN GOTO waitkey2
 CLS : flag$ = "restart": GOTO setmode
loadtemp:
 OUT &H3C4, 2: OUT &H3C5, 1: BLOAD "temp1.bin"
 OUT &H3C4, 2: OUT &H3C5, 2: BLOAD "temp2.bin"
 OUT &H3C4, 2: OUT &H3C5, 4: BLOAD "temp3.bin"
 OUT &H3C4, 2: OUT &H3C5, 8: BLOAD "temp4.bin"
 GOTO restart
clearscreen:
 OUT &H3C4, 2: OUT &H3C5, 15: CLS : GOTO begin
endofprogram:
 SCREEN 0: CLS : DEF SEG : END