Look at the screen text and the memory, and load a disk, from a program that runs the machine

ScreenText, Peek, GetPC and LoadDisk, for the programs that drive the
machine with RunCycles, like the activities of apple2-activities.

apple2Tester.go

@@ -67,21 +67,7 @@ func (at *apple2Tester) getText(textMode testTextModeFunc) string {
 }
 
 func (at *apple2Tester) getTextBest() string {
-	videxMaybe := at.a.cards[3]
-	if videxMaybe != nil {
-		if videx, ok := videxMaybe.(*CardVidexVideoterm); ok {
-			return videx.getText()
-		}
-		if videxUltraterm, ok := videxMaybe.(*CardVidexUltraterm); ok {
-			return videxUltraterm.getText()
-		}
-	}
-
-	videoMode := at.a.video.GetCurrentVideoMode()
-	if videoMode&screen.VideoBaseMask == screen.VideoText80 {
-		return at.getText(testTextMode80)
-	}
-	return at.getText(testTextMode40)
+	return at.a.ScreenText()
 }
 
 /*

inspect.go

@@ -0,0 +1,52 @@
+package izapple2
+
+import (
+	"github.com/ivanizag/izapple2/screen"
+)
+
+/*
+What a program driving the machine with RunCycles needs to look at it and to
+change its media, the way a person at the keyboard would: the text on the
+screen, the memory, and the diskettes. They must be called from the goroutine
+that calls RunCycles, or while the machine is not running.
+*/
+
+// ScreenText returns the text shown on the screen, in 40 or 80 columns or on
+// a Videx card in slot 3, with a line per row. Inverse and flashing
+// characters are returned as the normal ones.
+func (a *Apple2) ScreenText() string {
+	switch videx := a.cards[3].(type) {
+	case *CardVidexVideoterm:
+		return videx.getText()
+	case *CardVidexUltraterm:
+		return videx.getText()
+	}
+
+	is80Columns := a.io.isSoftSwitchActive(ioFlag80Col)
+	isSecondPage := a.io.isSoftSwitchActive(ioFlagSecondPage) && !a.mmu.store80Active
+	isAltText := a.io.isSoftSwitchActive(ioFlagAltChar)
+	return screen.RenderTextModeString(a.video, is80Columns, isSecondPage, isAltText, a.hasLowerCase, false)
+}
+
+// Peek returns the byte the processor would read at an address, with the
+// memory banks as they are now. The I/O area from 0xc000 to 0xcfff returns
+// 0, as reading it can change the state of the machine.
+func (a *Apple2) Peek(address uint16) uint8 {
+	if address >= 0xc000 && address < 0xd000 {
+		return 0
+	}
+	return a.mmu.Peek(address)
+}
+
+// GetPC returns the program counter of the processor
+func (a *Apple2) GetPC() uint16 {
+	pc, _ := a.cpu.GetPCAndSP()
+	return pc
+}
+
+// LoadDisk inserts a file on a removable media drive, numbered in the order
+// of GetRemovableMediaDrives, right away. SendLoadDisk does the same from
+// another goroutine, and only reports the errors on the console.
+func (a *Apple2) LoadDisk(unit int, path string) error {
+	return a.changeDisk(unit, path)
+}