Add verbose function to the emulator and correct some terminology in and reword the readme slightly

emulator.pas

@@ -18,8 +18,8 @@ const
     IO = $ffff;
 
 var
-    Hlt, ASCII: boolean; //Halt and ASCII flags
+    Hlt, ASCII, Verbose: boolean; //Halt, ASCII, and verbose flags
-    Op: 0 .. $f; //Opcode
+    Op, Regs: 0 .. $f; //Opcode
     X, Y: 0 .. 3; //Register arguments
     Addr, IP, RP: word; //Address argument and instruction and return pointers
     R: array [0 .. 3] of byte; //General-purpose registers
@@ -78,13 +78,30 @@ begin
     Punch.Pos := 0;
     {$endif}
 
-    //Read a program file and check for errors
+    //Check the arguments
-    if ParamCount <> 1 then begin
+    if ParamCount = 0 then begin
-        writeln ('Usage: emulator program');
+        writeln ('Usage: emulator (-v) program (2> verbose_output)');
         halt;
     end;
+    if ParamStr (1) = '-v' then begin
+        Verbose := true;
+        if ParamCount <> 2 then begin
+            writeln ('Usage: emulator (-v) program (2> verbose_output)');
+            halt;
+        end;
+    end
+    else begin
+        Verbose := false;
+        if ParamCount <> 1 then begin
+            writeln ('Usage: emulator (-v) program (2> verbose_output)');
+            halt;
+        end;
+    end;
+
+    //Read a program file and check for errors
     {$i-}
-    assign (Prog, ParamStr (1));
+    if Verbose = true then assign (Prog, ParamStr (2))
+    else assign (Prog, ParamStr (1));
     reset (Prog);
     {$i+}
     if IOResult <> 0 then begin
@@ -106,10 +123,14 @@ begin
     //Begin the main loop
     while Hlt = false do begin
 
+        //Print the CPU state to StdErr
+        if Verbose = true then writeln (StdErr, 'IR: ', IntToHex (Op, 1), IntToHex (Regs, 1), IntToHex (Addr, 4), '; IP: ', IntToHex (IP, 4), ', RP: ', IntToHex (RP, 4), '; R0: ', IntToHex (R[0], 2), ', R1: ', IntToHex (R[1], 2), ', R2: ', IntToHex (R[2], 2), ', R3: ', IntToHex (R[3], 2), ansichar ($d));
+
         //Fetch the instruction and increment the instruction pointer
         //Opcode
         Op := Mem [IP] and $f0 shr 4;
         //Register arguments
+        Regs := Mem [IP] and $f;
         X := Mem [IP] and $c shr 2;
         Y := Mem [IP] and 3;
         IP := IP + 1;
@@ -134,7 +155,8 @@ begin
                 writeln ('Error: illegal instruction pointer value');
                 halt;
             end;
-        end;
+        end
+        else Addr := 0;
 
         //Decode and execute the instruction
         //Halt

readme.md

@@ -17,7 +17,7 @@ Assembly.
 Speed
 -----
 
-Thingamajig does not have a prescribed speed. The emulator should run at
+Thingamajig does not have a prescribed speed. The emulator runs at
 roughly 500 KIPS.
 
 Registers and Memory
@@ -92,13 +92,13 @@ reference to or relative to a label.
 Memory-Mapped Devices
 ---------------------
 
-Input and output are mapped to address FFFF. The emulator emulates a
+Input and output are mapped to address FFFF; the emulator emulates a
-glass teletype with local echo.
+roughly 1000 CPS glass teletype with local echo.
 
 Arbitrary devices can be mapped to the other reserved addresses.
 
-In Linux the emulator can be compiled with support for a line printer
+In Linux the emulator can be compiled with support for a character
-and an emulated punched tape reader and punch with the arguments
+printer and an emulated punched tape reader and punch with the arguments
 -dprinter and -dtape respectively. The printer is mapped to address FFFE
 and the tape reader and punch to FFFD. The printer prints into
 /dev/usb/lp0 and the tape files read from and punched to are (re)set