From cc1c6568ff2ab4666a7e9e1cfbd843a277c44aa0 Mon Sep 17 00:00:00 2001
From: Dirk Hoffmann <dirk.hoffmann@me.com>
Date: Fri, 6 Sep 2024 12:09:31 +0200
Subject: [PATCH] Passing all QuickReuTest-1.1.1 tests (#809)

---
 .../Media/Cartridges/CustomCartridges/Reu.cpp | 36 ++++++++++++-------
 .../Media/Cartridges/CustomCartridges/Reu.h   |  6 ++++
 Emulator/config.cpp                           |  2 +-
 3 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/Emulator/Media/Cartridges/CustomCartridges/Reu.cpp b/Emulator/Media/Cartridges/CustomCartridges/Reu.cpp
index cbbd91932..24ba31510 100644
--- a/Emulator/Media/Cartridges/CustomCartridges/Reu.cpp
+++ b/Emulator/Media/Cartridges/CustomCartridges/Reu.cpp
@@ -442,10 +442,14 @@ Reu::initiateDma()
 void
 Reu::processEvent(EventID id)
 {
+    delay = 0;
+
     switch (id) {
 
         case EXP_REU_PREPARE:
 
+            verifyError = false;
+
             switch (cr & 0x3) {
 
                 case 0: id = EXP_REU_STASH; break;
@@ -471,7 +475,10 @@ Reu::processEvent(EventID id)
             // Perform a DMA cycle
             auto remaining = doDma(id);
 
-            if (remaining == -1) {
+            // Set or clear the END_OF_BLOCK_BIT
+            tlength == 1 ? SET_BIT(sr, 6) : CLR_BIT(sr, 6);
+
+            if (remaining == -1 && tlength != 1) {
 
                 // Verify error: Emulate a 1 cycle delay
                 c64.scheduleRel<SLOT_EXP>(1, EXP_REU_AUTOLOAD);
@@ -485,6 +492,7 @@ Reu::processEvent(EventID id)
                 break;
             }
 
+            if (delay) { c64.scheduleRel<SLOT_EXP>(delay, EXP_REU_AUTOLOAD); break; }
             [[fallthrough]];
         }
         case EXP_REU_AUTOLOAD:
@@ -498,23 +506,18 @@ Reu::processEvent(EventID id)
                 tlength = tlengthLatched;
 
                 // Emulate a 4 cycle delay
-                if (id != EXP_REU_SWAP) {
-
-                    c64.scheduleRel<SLOT_EXP>(4, EXP_REU_FINALIZE);
-                    break;
-                }
+                if (id != EXP_REU_SWAP) delay = 4;
 
             } else {
 
                 debug(REU_DEBUG, "No autoload\n");
             }
+
+            if (delay) { c64.scheduleRel<SLOT_EXP>(delay, EXP_REU_FINALIZE); break; }
             [[fallthrough]];
 
         case EXP_REU_FINALIZE:
 
-            // Set or clear the END_OF_BLOCK_BIT
-            tlength == 1 ? SET_BIT(sr, 6) : CLR_BIT(sr, 6);
-
             finalizeDma(id);
             c64.cancel<SLOT_EXP>();
             break;
@@ -587,6 +590,9 @@ Reu::doDma(EventID id)
                 // Trigger interrupt if enabled
                 triggerVerifyErrorIrq();
 
+                verifyError = true;
+                delay = tlength == 1 ? 0 : 1;
+                if (tlength != 1) U16_DEC(tlength, 1);
                 return -1;
             }
             break;
@@ -595,7 +601,11 @@ Reu::doDma(EventID id)
             fatalError;
     }
 
-    if (tlength == 1) return 0;
+    if (tlength == 1) {
+
+        triggerEndOfBlockIrq();
+        return 0;
+    }
 
     U16_DEC(tlength, 1);
     return tlength;
@@ -604,7 +614,7 @@ Reu::doDma(EventID id)
 void 
 Reu::finalizeDma(EventID id)
 {
-    triggerEndOfBlockIrq();
+    // if (!verifyError) triggerEndOfBlockIrq();
 
     // Release the CPU
     cpu.releaseRdyLine(INTSRC_EXP);
@@ -618,7 +628,7 @@ Reu::triggerEndOfBlockIrq()
         sr |= 0x80;
         cpu.pullDownIrqLine(INTSRC_EXP);
 
-        debug(REU_DEBUG, "IRQ triggered (sr = %02x)\n", sr);
+        debug(REU_DEBUG, "End-of-block IRQ triggered (sr = %02x)\n", sr);
     }
 }
 
@@ -629,6 +639,8 @@ Reu::triggerVerifyErrorIrq()
 
         sr |= 0x80;
         cpu.pullDownIrqLine(INTSRC_EXP);
+
+        debug(REU_DEBUG, "Verify-error IRQ triggered (sr = %02x)\n", sr);
     }
 }
 
diff --git a/Emulator/Media/Cartridges/CustomCartridges/Reu.h b/Emulator/Media/Cartridges/CustomCartridges/Reu.h
index 1f8c12a10..8ebb3f1e8 100644
--- a/Emulator/Media/Cartridges/CustomCartridges/Reu.h
+++ b/Emulator/Media/Cartridges/CustomCartridges/Reu.h
@@ -87,9 +87,15 @@ class Reu final : public Cartridge {
     // Address control register (0x0A)
     u8 acr = 0;
 
+    // Signals a verify error
+    bool verifyError = false;
+    
     // Flipflop used to control the swap operation
     bool swapff = false;
 
+    // Used inside processEvent() to emulate additional delay cycles
+    isize delay = 0;
+
 
     //
     // Emulation specific variables
diff --git a/Emulator/config.cpp b/Emulator/config.cpp
index f98e3a9d6..d4a401731 100644
--- a/Emulator/config.cpp
+++ b/Emulator/config.cpp
@@ -80,7 +80,7 @@ debugflag USR_DEBUG       = 0;
 
 // Other components
 debugflag REC_DEBUG       = 0;
-debugflag REU_DEBUG       = 1;
+debugflag REU_DEBUG       = 0;
 debugflag SCK_DEBUG       = 0;
 debugflag SRV_DEBUG       = 0;