peek and poke double words

ivanizag · Sep 6, 2021 · e1ab9e0 · e1ab9e0
1 parent b69cdbe
commit e1ab9e0
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Showing 4 changed files with 31 additions and 17 deletions.
diff --git a/acornMemory.go b/acornMemory.go
@@ -168,6 +168,20 @@ func (m *acornMemory) pokeWord(address uint16, value uint16) {
 	m.Poke(address+1, uint8(value>>8))
 }
 
+func (m *acornMemory) peekDoubleWord(address uint16) uint32 {
+	return uint32(m.Peek(address)) +
+		uint32(m.Peek(address+1))<<8 +
+		uint32(m.Peek(address+2))<<16 +
+		uint32(m.Peek(address+3))<<24
+}
+
+func (m *acornMemory) pokeDoubleWord(address uint16, value uint32) {
+	m.Poke(address, uint8(value))
+	m.Poke(address+1, uint8(value>>8))
+	m.Poke(address+2, uint8(value>>16))
+	m.Poke(address+3, uint8(value>>24))
+}
+
 func (m *acornMemory) peeknbytes(address uint16, n int) uint64 {
 	ticks := uint64(0)
 	for i := n - 1; i >= 0; i-- {

diff --git a/osArgs.go b/osArgs.go
@@ -48,12 +48,12 @@ func execOSARGS(env *environment) {
 		if err != nil {
 			env.raiseError(errorTodo, err.Error())
 		} else {
-			env.mem.pokenbytes(uint16(x), 4, uint64(pos))
+			env.mem.pokeDoubleWord(uint16(x), uint32(pos))
 		}
 		env.log(fmt.Sprintf("OSARGS('Get PTR#',FILE=%v) => %v", y, pos))
 
 	case 1: // Write sequential pointer of file
-		pos := int64(env.mem.peeknbytes(uint16(x), 4))
+		pos := int64(env.mem.peekDoubleWord(uint16(x)))
 		_, err := file.Seek(pos, io.SeekStart)
 		if err != nil {
 			env.raiseError(errorTodo, err.Error())
@@ -65,7 +65,7 @@ func execOSARGS(env *environment) {
 		if err != nil {
 			env.raiseError(errorTodo, err.Error())
 		} else {
-			env.mem.pokenbytes(uint16(x), 4, uint64(info.Size()))
+			env.mem.pokeDoubleWord(uint16(x), uint32(info.Size()))
 		}
 		env.log(fmt.Sprintf("OSARGS('Get EXT#',FILE=%v)=%v", y, info.Size()))
 

diff --git a/osFile.go b/osFile.go
@@ -37,10 +37,10 @@ func execOSFILE(env *environment) {
 	// See: http://beebwiki.mdfs.net/OSFILE
 	controlBlock := uint16(x) + uint16(y)<<8
 	filenameAddress := env.mem.peekWord(controlBlock)
-	loadAddress := uint32(env.mem.peeknbytes(controlBlock+cbLoadAddress, 4))
-	executionAddress := uint32(env.mem.peeknbytes(controlBlock+cbExecutionAddress, 4))
-	startAddress := uint32(env.mem.peeknbytes(controlBlock+cbStartAddressOrSize, 4))
-	endAddress := uint32(env.mem.peeknbytes(controlBlock+cbEndAddressOrAttributes, 4))
+	loadAddress := env.mem.peekDoubleWord(controlBlock + cbLoadAddress)
+	executionAddress := env.mem.peekDoubleWord(controlBlock + cbExecutionAddress)
+	startAddress := env.mem.peekDoubleWord(controlBlock + cbStartAddressOrSize)
+	endAddress := env.mem.peekDoubleWord(controlBlock + cbEndAddressOrAttributes)
 
 	filename := env.mem.getString(filenameAddress, 0x0d)
 
@@ -65,10 +65,10 @@ func execOSFILE(env *environment) {
 		*/
 		attr := getFileAttributes(env, filename)
 		if attr.fileType != osNotFound {
-			env.mem.pokenbytes(controlBlock+cbStartAddressOrSize, 4, uint64(attr.fileSize))
+			env.mem.pokeDoubleWord(controlBlock+cbStartAddressOrSize, attr.fileSize)
 			if attr.hasMetadata {
-				env.mem.pokenbytes(controlBlock+cbLoadAddress, 4, uint64(attr.loadAddress))
-				env.mem.pokenbytes(controlBlock+cbExecutionAddress, 4, uint64(attr.executionAddress))
+				env.mem.pokeDoubleWord(controlBlock+cbLoadAddress, attr.loadAddress)
+				env.mem.pokeDoubleWord(controlBlock+cbExecutionAddress, attr.executionAddress)
 			}
 		}
 		newA = attr.fileType
@@ -89,7 +89,7 @@ func execOSFILE(env *environment) {
 		}
 
 		attr := loadFile(env, filename, loadAddress)
-		env.mem.pokenbytes(controlBlock+cbStartAddressOrSize, 4, uint64(attr.fileSize))
+		env.mem.pokeDoubleWord(controlBlock+cbStartAddressOrSize, attr.fileSize)
 		newA = attr.fileType
 
 	default:

diff --git a/osGbpb.go b/osGbpb.go
@@ -47,9 +47,9 @@ func execOSGBPB(env *environment) {
 
 		controlBlock := uint16(x) + uint16(y)<<8
 		handle := env.mem.Peek(controlBlock)
-		address := uint32(env.mem.peeknbytes(controlBlock+cbDataAddress, 4))
-		count := uint32(env.mem.peeknbytes(controlBlock+cbDataCount, 4))
-		offset := uint32(env.mem.peeknbytes(controlBlock+cbDataOffset, 4))
+		address := env.mem.peekDoubleWord(controlBlock + cbDataAddress)
+		count := env.mem.peekDoubleWord(controlBlock + cbDataCount)
+		offset := env.mem.peekDoubleWord(controlBlock + cbDataOffset)
 
 		error := false
 		file := env.getFile(handle)
@@ -91,9 +91,9 @@ func execOSGBPB(env *environment) {
 		}
 
 		// Update the file control block
-		env.mem.pokenbytes(controlBlock+cbDataAddress, 4, uint64(address+transferred))
-		env.mem.pokenbytes(controlBlock+cbDataCount, 4, uint64(count-transferred))
-		env.mem.pokenbytes(controlBlock+cbDataOffset, 4, uint64(offset+transferred))
+		env.mem.pokeDoubleWord(controlBlock+cbDataAddress, address+transferred)
+		env.mem.pokeDoubleWord(controlBlock+cbDataCount, count-transferred)
+		env.mem.pokeDoubleWord(controlBlock+cbDataOffset, offset+transferred)
 
 		newP := p
 		if count-transferred != 0 {