From fd0b547e7e050b9613cdf67a5c27d110d294d9cd Mon Sep 17 00:00:00 2001
From: Martin Haye <m1@snyder-haye.com>
Date: Fri, 8 Jul 2016 17:19:59 -0700
Subject: [PATCH] Sprinkled in some SEI/CLI to help with future interrupt
 probs. Fixed yet another problem with the memory accessor patch to PLASMA.

---
 Platform/Apple/virtual/src/core/mem.s       | 18 +++++++++++++++---
 Platform/Apple/virtual/src/raycast/render.s |  8 ++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/Platform/Apple/virtual/src/core/mem.s b/Platform/Apple/virtual/src/core/mem.s
index 366f017f..469f5117 100644
--- a/Platform/Apple/virtual/src/core/mem.s
+++ b/Platform/Apple/virtual/src/core/mem.s
@@ -122,12 +122,14 @@ relocate:
 ; verify that aux mem exists
 	inx
 	stx $D000
+	sei			; disable interrupts while in aux
 	sta setAuxZP
 	inx
 	stx $D000
 	cpx $D000
 	bne .noaux
 	sta clrAuxZP
+	cli
 	dex
 	cpx $D000
 	beq .gotaux
@@ -135,12 +137,14 @@ relocate:
 .gotaux	ldx #$D0
 .pglup	stx .ld+2
 	stx .st+2
+	sei
 .bylup	sta clrAuxZP		; get byte from main LC
 .ld	lda $D000,y
 	sta setAuxZP		; temporarily turn on aux LC
 .st	sta $D000,y
 	iny
 	bne .bylup
+	cli
 	inx			; all pages until we hit $00
 	bne .pglup
 	sta clrAuxZP		; ...back to main LC
@@ -458,14 +462,14 @@ SWXX:	bit monrts		; set V to denote SWX (not SBX)
 .shst	lda evalStkH+1,x	; get hi byte of pointer to store to
 	cmp #$D0		; in $0000.CFFF range,
 	bcc .norm		;	just do normal store
-	cmp #$E0		; in $E000.FFFF range do normal store after write-enable
 	; Apple IIc note: turning on LC requires a 6502 read, not write. So putting sta below didn't work.
+	pha
 	lda setLcRW+lcBank2	; PLASMA normally write-protects the LC,
 	lda setLcRW+lcBank2	; 	but let's allow writing there. Don't use BIT as it affects V flg.
+	pla
+	cmp #$E0		; in $E000.FFFF range do normal store after write-enable
 	bcs .norm
-	sty tmp
 	jsr l_SXXX		; helper function in low memory because it switches us out (we're in main LC)
-	ldy tmp
 	inx
 	inx
 	jmp plasmaNextOp
@@ -643,6 +647,8 @@ l_LXXX:	!zone {
 
 l_SXXX:	!zone {
 	sta .st+2		; in $D000.DFFF range, we jump through hoops to write to AUX LC
+	tya
+	pha
 	lda evalStkL+1,x	; lo byte of pointer
 	sta .st+1
 	lda evalStkH,x		; hi byte of value to store
@@ -657,6 +663,8 @@ l_SXXX:	!zone {
 	cpy #2
 	bne .st			; loop to write hi byte also
 +	sta clrAuxZP		; back to main LC
+	pla
+	tay
 	rts
 }
 
@@ -2618,6 +2626,7 @@ lz4Decompress: !zone
 	bne +
 	dec ucLen+1		; special case for len being an exact multiple of 256
 +
+	sei			; prevent interrupts while we access aux mem
 .auxWr2	sta setAuxWr		; self-modified earlier, based on isAuxCmd
 .auxRd1	sta setAuxRd  		; self-modified based on isAuxCmd
 .srcLoad:
@@ -2637,6 +2646,7 @@ lz4Decompress: !zone
 	bpl .srcLoad		; loop for more. NOTE: this would fail if we had blocks >= 32K
 	sta clrAuxRd		; back to reading main mem, for mem mgr code
 	sta clrAuxWr		; back to writing main mem
+	cli
 	inc ucLen+1		; to make it zero for the next match decode
 + 	ldy tmp			; restore index to source pointer
 	jmp .getToken		; go on to the next token in the compressed stream
@@ -2760,6 +2770,7 @@ nextSrcPage:
 doAllFixups: !zone
 	!if DEBUG >= 2 { +prStr : !text "Doing all fixups.",0 }
 	; Now scan aux mem for fixup segments
+	cli			; prevent interrupts while we mess around in aux mem
 	ldx #1			; start at first aux mem segment (0=main mem, 1=aux)
 .loop:	lda tSegType,x		; grab flags & type
 	and #$F			; just type now
@@ -2768,6 +2779,7 @@ doAllFixups: !zone
 .next:	lda tSegLink,x		; next in chain
 	tax			; to X reg index
 	bne .loop		; non-zero = not end of chain - loop again
+	sei			; allow interrupts again
 	lda #1
 	sta isAuxCmd
 	jmp coalesce		; really free up the fixup blocks by coalescing them into free mem
diff --git a/Platform/Apple/virtual/src/raycast/render.s b/Platform/Apple/virtual/src/raycast/render.s
index 93967d35..6f96faf2 100644
--- a/Platform/Apple/virtual/src/raycast/render.s
+++ b/Platform/Apple/virtual/src/raycast/render.s
@@ -1259,7 +1259,9 @@ drawRay: !zone
 	lda #254		; clamp max height
 +	sta expanderJmp+1	; set vector offset
 	!if DEBUG >= 2 { +prStr : !text "Calling expansion code.",0 }
+	sei			; prevent interrupts while in aux mem
 	jsr callExpander	; was copied from .callIt to $100 at init time
+	cli			; interrupts ok after we get back from aux
 .skip	pla			; retrieve link to next in stack
 	tax			; put in X for indexing
 	bne .lup		; if non-zero, we have more to draw
@@ -1492,6 +1494,7 @@ makeLines: !zone
 	sta pLine
 	lda #>TOP_LINE
 	sta pLine+1
+	sei
 .lup:	lda lineCt
 	asl
 	tax
@@ -1506,6 +1509,7 @@ makeLines: !zone
 	lda lineCt
 	cmp #NLINES
 	bne .lup
+	cli
 	rts
 
 ; Set screen lines to current back buf
@@ -1519,6 +1523,7 @@ setBackBuf: !zone
 	asl
 	clc
 	adc #$20
+	sei
 	sta setAuxZP
 	ldx #0
 .lup:	eor 1,x
@@ -1529,6 +1534,7 @@ setBackBuf: !zone
 	inx
 	bne .lup
 	sta clrAuxZP
+	cli
 	rts
 
 ;-------------------------------------------------------------------------------
@@ -1902,9 +1908,11 @@ renderFrame: !zone
 	ldy byteNum
 	iny			; move to right 2 bytes to preserve frame border
 	iny
+	sei
 	sta setAuxZP
 	jsr blitRoll
 	sta clrAuxZP
+	cli
 	lda #0
 	sta pixNum
 	inc byteNum