o tia

- reverted motion clock timings from 480ff22670eb8898b0d15d5f884257232db584bf
    - this visually breaks Keystone Kapers ROM again but this was
    definitely not the right solution because the fix broke both Yar's
    Revenge and the stress-test-cards.

* I really now need to implement automatic regression tests

o debugger
    - implemented grepping of disassembly

debugger/commands.go

@@ -53,6 +53,7 @@ const (
 	KeywordMouse         = "MOUSE"
 	KeywordScript        = "SCRIPT"
 	KeywordDisassemble   = "DISASSEMBLE"
+	KeywordGrep          = "GREP"
 )
 
 // Help contains the help text for the debugger's top level commands
@@ -94,6 +95,7 @@ var Help = map[string]string{
 	KeywordMouse:         "Return the coordinates of the last mouse press",
 	KeywordScript:        "Run commands from specified file",
 	KeywordDisassemble:   "Print the full cartridge disassembly",
+	KeywordGrep:          "Simple string search (case insensitive) of the disassembly",
 }
 
 var commandTemplate = input.CommandTemplate{
@@ -133,6 +135,7 @@ var commandTemplate = input.CommandTemplate{
 	KeywordMouse:         "[|X|Y]",
 	KeywordScript:        "%F",
 	KeywordDisassemble:   "",
+	KeywordGrep:          "%S %*",
 }
 
 // notes
@@ -222,6 +225,16 @@ func (dbg *Debugger) parseCommand(userInput string) (bool, error) {
 	case KeywordDisassemble:
 		dbg.disasm.Dump(os.Stdout)
 
+	case KeywordGrep:
+		search := tokens.Remainder()
+		output := strings.Builder{}
+		dbg.disasm.Grep(search, &output, false)
+		if output.Len() == 0 {
+			dbg.print(ui.Error, "%s not found in disassembly", search)
+		} else {
+			dbg.print(ui.Feedback, output.String())
+		}
+
 	case KeywordSymbol:
 		// TODO: change this so that it uses debugger.memory front-end
 		symbol, _ := tokens.Get()

disassembly/disassembly.go

@@ -9,6 +9,7 @@ import (
 	"gopher2600/hardware/memory"
 	"gopher2600/symbols"
 	"io"
+	"strings"
 )
 
 // Disassembly represents the annotated disassembly of a 6502 binary
@@ -126,3 +127,26 @@ func (dsm *Disassembly) Dump(output io.Writer) {
 		output.Write([]byte("\n"))
 	}
 }
+
+// Grep searches the disassembly dump for search string. case sensitive
+func (dsm *Disassembly) Grep(search string, output io.Writer, caseSensitive bool) {
+	var s, m string
+
+	if !caseSensitive {
+		search = strings.ToUpper(search)
+	}
+
+	for _, pc := range dsm.SequencePoints {
+		s = dsm.Program[pc].GetString(dsm.Symtable, result.StyleBrief)
+		if !caseSensitive {
+			m = strings.ToUpper(s)
+		} else {
+			m = s
+		}
+
+		if strings.Contains(m, search) {
+			output.Write([]byte(s))
+			output.Write([]byte("\n"))
+		}
+	}
+}

hardware/tia/tia.go

@@ -151,7 +151,7 @@ func (tia *TIA) StepVideoCycle() bool {
 
 	// motion clock is an out-of-phase color clock. note that the motion clock
 	// does not care about HMOVE.
-	if tia.colorClock.MatchEnd(8) {
+	if tia.colorClock.MatchEnd(15) {
 		tia.motionClock = true
 	} else if tia.colorClock.MatchEnd(56) {
 		tia.motionClock = false