new file mode 100644

@@ -0,0 +1,111 @@

+@load-rom ( filename* -- )

+(

+	Attempts to load the ROM from filename* and executes it. If the file exists

+	and has non-zero length, this function does not return, because the new ROM

+	is executing in its place.

+

+	The screen and both stacks are cleared and all the device vectors are

+	written to zero as a convenience. All other device bytes are left

+	untouched, so they could introduce a device state to the next ROM that

+	it's not expecting.

+)

+

+	.File/name DEO2

+	#0000 .File/offset-hs DEO2

+	#0000 .File/offset-ls DEO2

+

+	( return if file can't be found, or zero length )

+	#0001 .File/length DEO2

+	;&tmp .File/load DEO2

+	.File/success DEI2 ORA JMP JMP2r

+

+	( clear wst )

+	#ab

+	&wst-loop

+	POP

+	.System/wst STH DEIr STHr #01 GTH ,&wst-loop JCN

+

+	( clear rst )

+	LITr ab

+	&rst-loop

+	POPr

+	.System/rst DEI ,&rst-loop JCN

+

+	( clear screen )

+	#01 .Screen/auto DEO

+	#0000 .Screen/y DEO2

+	.Screen/width DEI2 #0007 ADD2 #03 SFT2 #ffff MUL2 STH2

+	&screen-yloop

+		#0000 .Screen/x DEO2

+		STH2kr

+		&screen-xloop-bg

+			#00 .Screen/sprite DEO

+			INC2

+			ORAk ,&screen-xloop-bg JCN

+		POP2

+		#0000 .Screen/x DEO2

+		STH2kr

+		&screen-xloop-fg

+			#40 .Screen/sprite DEO

+			INC2

+			ORAk ,&screen-xloop-fg JCN

+		POP2

+		.Screen/y DEI2 #0008 ADD2

+		DUP2 .Screen/y DEO2

+		.Screen/height DEI2 LTH2 ,&screen-yloop JCN

+	POP2r

+	#00 .Screen/auto DEO

+

+	( reset device vectors )

+	LIT2r 0000 #00

+	&device-vector-loop

+	DUP2r STHk DEO2r

+	#10 ADD

+	DUP ,&device-vector-loop JCN

+	POP POP2r

+

+	( copy the zero-page-loader into f0-ff )

+	;&zero-page-loader LIT2r 00f0

+	&copy-loop

+	LDAk STH2kr STA

+	INC2 INC2r

+	STHkr ,&copy-loop JCN

+	POP2 NIPr ( leave 00 on return stack )

+

+	( prepare the stack for the zero-page-loader )

+	( the more we prepare here in advance, the less we'll have to overwrite )

+	STHkr DUPk #fe ( arguments for STA2 at ff )

+	OVR2 ( argument for JMP at fe (carry on), plus an extra zero )

+	DUP2 #fcfe ( arguments for STA2 at fd and JMP (repeat) )

+	OVR2 STHkr #fafe ( arguments for STA2 at fd and JMP (repeat) )

+	OVR2 STHkr #f8fe ( arguments for STA2 at fd and JMP (repeat) )

+	OVR2 STHkr #f6fe ( arguments for STA2 at fd and JMP (repeat) )

+	OVR2 STHkr #f4fe ( arguments for STA2 at fd and JMP (repeat) )

+	OVR2 STHkr #f2fe ( arguments for STA2 at fd and JMP (repeat) )

+	OVR2 STHkr #f001 ( arguments for STA2 at fd, plus an extra 01 )

+	STHkr ( first argument for ADD2 )

+	.File/success ( argument for DEI2 )

+	#0100 .File/load ( arguments for DEO2 )

+	#ff00 .File/length DEO2

+	#00f0 JMP2

+

+	&zero-page-loader

+	( f0 ) DEO2

+	( f1 ) DEI2

+	( f2 ) ADD2

+	( f3 ) &loop DUPr

+	( f4 ) STH2k

+	( f5 ) STAr

+	( f6 ) INC2

+	( f7 ) NEQ2k

+	( f8 ) ,&loop

+	( f9 )

+	( fa ) JCN

+	( fb ) POPr

+	( fc ) POP2

+	( fd ) STA2 ( deletes f0-fd through looping )

+	( fe ) JMP

+	( ff ) STA2 ( deletes fe-ff )

+

+	&tmp $1

+

@@ -17,9 +17,9 @@

 ( devices )

-|00 @System  &vector $2 &pad     $6 &r      $2 &g     $2 &b      $2

+|00 @System     [ &vector $2 &wst      $1 &rst    $1 &pad   $4 &r      $2 &g      $2 &b    $2 &debug  $1 &halt $1 ]

 |10 @Console    [ &vector $2 &read     $1 &pad    $5 &write $1 &error  $1 ]

-|20 @Screen  &vector $2 &width   $2 &height $2 &pad   $2 &x      $2 &y      $2 &addr $2 &pixel $1 &sprite $1

+|20 @Screen  &vector $2 &width   $2 &height $2 &auto $1 &pad $1 &x      $2 &y      $2 &addr $2 &pixel $1 &sprite $1

 |80 @Controller [ &vector $2 &button $1 &key    $1 ]

 |90 @Mouse      [ &vector $2 &x        $2 &y      $2 &state $1 &wheel  $1 ]

 |a0 @File    &vector $2 &success $2 &offset-hs $2 &offset-ls $2 &name $2 &length $2 &load $2 &save $2

@@ -106,7 +106,7 @@ BRK

 	RTN

 	&validate ( -- )

-		;input ;launch JSR2

+		;input ;load-rom JSR2

 		#00 ,&draw JSR

 		( null ) #0000 ;input STA2

 	RTN

@@ -134,14 +134,6 @@ BRK

 RTN

-@launch ( path* -- )

-

-	POP2

-

-	#0020 #00e0 ;error-txt #08 ;draw-label JSR2

-

-RTN

-

 @redraw ( -- )

 	#0018 #0020 #0040 #0040 ;logo-icn #03 ;draw-icn JSR2

@@ -277,6 +269,8 @@ RTN

 RTN

+include projects/library/load-rom.tal

+

 @welcome-txt

 	"Welcome 20 "to 20 "your 20 "UXN 20 "Ordinator $1

 @today-txt

@@ -158,7 +158,7 @@ redraw(Uxn *u)

 	SDL_Rect up = gRect;

 	if(devsystem->dat[0xe])

 		inspect(&ppu, u->wst.dat, u->wst.ptr, u->rst.ptr, u->ram.dat);

-	if(ppu.redraw) {

+	if(!reqdraw && ppu.redraw) {

 		y0 = ppu.i0 / ppu.stride;

 		y1 = ppu.i1 / ppu.stride + 1;

 		up.y += y0;