From a434c346f81a599619a8b7e6e4b4ff825ece701c Mon Sep 17 00:00:00 2001
From: Christian Zietz <czietz@gmx.net>
Date: Tue, 14 Oct 2025 17:58:37 +0200
Subject: [PATCH] WIP: Add a delay to the ACSI IRQ

---
 src/cycInt.c          |  4 +++-
 src/hdc.c             | 13 ++++++++++++-
 src/includes/cycInt.h |  1 +
 src/includes/hdc.h    |  2 ++
 4 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/cycInt.c b/src/cycInt.c
index 62b5f273..f65908cc 100644
--- a/src/cycInt.c
+++ b/src/cycInt.c
@@ -57,6 +57,7 @@ const char CycInt_fileid[] = "Hatari cycInt.c";
 #include "dmaSnd.h"
 #include "crossbar.h"
 #include "fdc.h"
+#include "hdc.h"
 #include "ikbd.h"
 #include "cycles.h"
 #include "cycInt.h"
@@ -109,7 +110,8 @@ static void (* const pIntHandlerFunctions[MAX_INTERRUPTS])(void) =
 	SCC_InterruptHandler_RX_A,
 	SCC_InterruptHandler_BRG_B,
 	SCC_InterruptHandler_TX_RX_B,
-	SCC_InterruptHandler_RX_B
+	SCC_InterruptHandler_RX_B,
+	HDC_InterruptHandler_Update,
 };
 
 /* Event timer structure - keeps next timer to occur in structure so don't need
diff --git a/src/hdc.c b/src/hdc.c
index f795c4e8..8cdb6f58 100644
--- a/src/hdc.c
+++ b/src/hdc.c
@@ -17,6 +17,8 @@ const char HDC_fileid[] = "Hatari hdc.c";
 #include "file.h"
 #include "fdc.h"
 #include "hdc.h"
+#include "cycles.h"
+#include "cycInt.h"
 #include "ioMem.h"
 #include "log.h"
 #include "m68000.h"
@@ -1148,7 +1150,8 @@ static void Acsi_DmaTransfer(void)
 	AcsiBus.data_len = 0;
 
 	FDC_SetDMAStatus(AcsiBus.bDmaError);	/* Mark DMA error */
-	FDC_SetIRQ(FDC_IRQ_SOURCE_HDC);
+	FDC_ClearHdcIRQ();
+	CycInt_AddRelativeInterrupt(2000, INT_CPU_CYCLE, INTERRUPT_ACSI_HD);
 
 	/* For the MegaSTE, using the HDC DMA will flush the external cache */
 	if ( ConfigureParams.System.nMachineType == MACHINE_MEGA_STE )
@@ -1235,3 +1238,11 @@ void HDC_DmaTransfer(void)
 	else if (bAcsiEmuOn)
 		Acsi_DmaTransfer();
 }
+
+
+
+void HDC_InterruptHandler_Update ( void )
+{
+	CycInt_AcknowledgeInterrupt();
+	FDC_SetIRQ(FDC_IRQ_SOURCE_HDC);
+}
\ No newline at end of file
diff --git a/src/includes/cycInt.h b/src/includes/cycInt.h
index 3dfb9293..f43705bd 100644
--- a/src/includes/cycInt.h
+++ b/src/includes/cycInt.h
@@ -39,6 +39,7 @@ typedef enum
   INTERRUPT_SCC_BRG_B,
   INTERRUPT_SCC_TX_RX_B,
   INTERRUPT_SCC_RX_B,
+  INTERRUPT_ACSI_HD,
 
   MAX_INTERRUPTS
 } interrupt_id;
diff --git a/src/includes/hdc.h b/src/includes/hdc.h
index 7c8f3dbf..aa90813e 100644
--- a/src/includes/hdc.h
+++ b/src/includes/hdc.h
@@ -106,4 +106,6 @@ extern off_t HDC_CheckAndGetSize(const char *hdtype, const char *filename, unsig
 extern bool HDC_WriteCommandPacket(SCSI_CTRLR *ctr, uint8_t b);
 extern void HDC_DmaTransfer(void);
 
+extern void	HDC_InterruptHandler_Update ( void );
+
 #endif /* HATARI_HDC_H */
-- 
2.30.2