From e236dcd7a6928d05d27225f1e32eeb1f91e4a734 Mon Sep 17 00:00:00 2001
From: Luigi Thirty <luigi30@gmail.com>
Date: Tue, 8 Aug 2017 03:00:16 -0400
Subject: [PATCH] working on prodos block support

---
 FruitMachine/AppleII/AppleIIBase.swift        |  4 +-
 .../Peripherals/DiskII/DiskImage.swift        | 88 +++++++++++++++++--
 FruitMachine/M6502/CPU.swift                  |  3 +-
 3 files changed, 87 insertions(+), 8 deletions(-)

diff --git a/FruitMachine/AppleII/AppleIIBase.swift b/FruitMachine/AppleII/AppleIIBase.swift
index 3e96f8d..c3ca3db 100644
--- a/FruitMachine/AppleII/AppleIIBase.swift
+++ b/FruitMachine/AppleII/AppleIIBase.swift
@@ -108,9 +108,9 @@ class AppleIIBase: NSObject, EmulatedSystem {
         let slot6 = defaults.string(forKey: "a2_Peripherals_Slot6")
         if(slot6 == "Disk II") {
             backplane[6] = DiskII(slot: 6, romPath: "/Users/luigi/apple2/341-0027-a.p5")
-            
-            let drive = backplane[6]! as! DiskII
         }
+        
+        (backplane[6] as! DiskII).attachDiskImage(imagePath: "/Users/luigi/apple2/Prodos_2_4_1.po")
     }
     
     func doColdReset() {
diff --git a/FruitMachine/AppleII/Peripherals/DiskII/DiskImage.swift b/FruitMachine/AppleII/Peripherals/DiskII/DiskImage.swift
index 68e8bd3..5e8f1a1 100644
--- a/FruitMachine/AppleII/Peripherals/DiskII/DiskImage.swift
+++ b/FruitMachine/AppleII/Peripherals/DiskII/DiskImage.swift
@@ -38,10 +38,10 @@ class Dos33Image: DiskImageFormat {
         //Find the track in our disk.
         let trackOffset = trackNum * Dos33Image.BYTES_PER_TRACK
         //Find the sector in this track.
-        let sectorOffset = SECTOR_ORDER[sectorNum] * Dos33Image.BYTES_PER_SECTOR
+        let sectorOffset = SECTOR_ORDER[sectorNum] * BYTES_PER_SECTOR
         let offset = trackOffset + sectorOffset
         
-        return Array<UInt8>(imageData[offset ..< offset + Dos33Image.BYTES_PER_SECTOR])
+        return Array<UInt8>(imageData[offset ..< offset + BYTES_PER_SECTOR])
     }
 }
 
@@ -63,6 +63,55 @@ class ProdosImage: DiskImageFormat {
         
         return Array<UInt8>(imageData[offset ..< offset + BYTES_PER_SECTOR])
     }
+    
+    static func readBlock(imageData: [UInt8], blockNum: Int) -> [UInt8] {
+        var blockData = [UInt8]()
+        
+        /* Find the track number. */
+        let track = blockNum / 8
+        
+        /* Find the sector numbers. */
+        let blockOffset8 = blockNum % 8
+        var sector1 = 0
+        var sector2 = 0
+        
+        switch blockOffset8 {
+        case 0:
+            sector1 = 0
+            sector2 = 2
+        case 1:
+            sector1 = 4
+            sector2 = 6
+        case 2:
+            sector1 = 8
+            sector2 = 0xA
+        case 3:
+            sector1 = 0xC
+            sector2 = 0xE
+            
+        case 4:
+            sector1 = 1
+            sector2 = 3
+        case 5:
+            sector1 = 5
+            sector2 = 7
+        case 6:
+            sector1 = 9
+            sector2 = 0xB
+        case 7:
+            sector1 = 0xD
+            sector2 = 0xF
+        default:
+            print("should never happen")
+        }
+        
+        /* First half of the interleaved block. */
+        blockData.append(contentsOf: readTrackAndSector(imageData: imageData, trackNum: track, sectorNum: sector1))
+        /* Second half of the interleaved block. */
+        blockData.append(contentsOf: readTrackAndSector(imageData: imageData, trackNum: track, sectorNum: sector2))
+        
+        return blockData
+    }
 }
 
 class DiskImage: NSObject {
@@ -105,9 +154,29 @@ class DiskImage: NSObject {
             image = ProdosImage()
             
             for track in 0..<ProdosImage.TRACKS_PER_DISK {
-                encodedTracks.append(encodeTrack(imageData: rawData!, index: track, volumeNumber: 0x01))
+                encodedTracks.append(encodeTrack(imageData: rawData!, index: track, volumeNumber: 0xFE))
             }
             
+            var blks = [UInt8]()
+            var nbls = [UInt8]()
+            
+            /*
+            for track in encodedTracks {
+                full.append(contentsOf: track)
+            }
+             */
+ 
+            blks.append(contentsOf: ProdosImage.readBlock(imageData: rawData!, blockNum: 0))
+            nbls.append(contentsOf: encodedTracks[0])
+        
+            var ptr = UnsafeBufferPointer(start: blks, count: blks.count)
+            var data = Data(buffer: ptr)
+            try! data.write(to: URL(fileURLWithPath: filename + ".blk"))
+            
+            ptr = UnsafeBufferPointer(start: nbls, count: nbls.count)
+            data = Data(buffer: ptr)
+            try! data.write(to: URL(fileURLWithPath: filename + ".nbl"))
+            
         } else {
             /* TODO: Hook up logic to figure out the disk format. */
             image = Dos33Image()
@@ -124,7 +193,7 @@ class DiskImage: NSObject {
         
         let ptr = UnsafeBufferPointer(start: diskBytes, count: diskBytes.count)
         let data = Data(buffer: ptr)
-        try! data.write(to: URL(fileURLWithPath: filename + ".modified"))
+        try! data.write(to: URL(fileURLWithPath: filename))
     }
     
     private func loadImageBytes(path: String, size: Int) -> [UInt8]? {
@@ -192,7 +261,16 @@ class DiskImage: NSObject {
             //Data Field
             encodedData.append(contentsOf: dataPrologue)
             //343 bytes: 342-byte sector + 1-byte checksum
-            encodedData.append(contentsOf: EncodeSectorSixAndTwo(sector: Dos33Image.readTrackAndSector(imageData: imageData, trackNum: index, sectorNum: sectorNum)))
+            if(image is Dos33Image) {
+                encodedData.append(contentsOf: EncodeSectorSixAndTwo(sector: Dos33Image.readTrackAndSector(imageData: imageData, trackNum: index, sectorNum: sectorNum)))
+            }
+            else if(image is ProdosImage){
+                /* TODO: A .PO image is stored by 512-blocks which are not contiguous on the disk. Need to adapt this to handle blocks. */
+                /*
+                encodedData.append(contentsOf: EncodeSectorSixAndTwo(sector: ProdosImage.readTrackAndSector(imageData: imageData, trackNum: index, sectorNum: sectorNum)))
+                 */
+            }
+
             encodedData.append(contentsOf: dataEpilogue)
             
             //Gap2 - 20 bytes
diff --git a/FruitMachine/M6502/CPU.swift b/FruitMachine/M6502/CPU.swift
index b5c03e8..600cbb9 100644
--- a/FruitMachine/M6502/CPU.swift
+++ b/FruitMachine/M6502/CPU.swift
@@ -283,7 +283,8 @@ final class CPU: NSObject {
         do {
             try executeNextInstruction()
         } catch CPUExceptions.invalidInstruction {
-            isRunning = false
+            print("Invalid instruction at \(program_counter.asHexString())")
+            coldReset()
         } catch {
             print(error)
         }