From 0898cca4b9eb3465bc4507508d352502f6e5781a Mon Sep 17 00:00:00 2001
From: Harley Travis <harleytravis123@outlook.com>
Date: Sat, 6 Jun 2026 19:35:22 -0500
Subject: Update DskFDC.HC

I have added a function that will check for the presence of valid sector data on either side of a floppy disk. This function is used to check for the presence of a disk in a way that does not rely on the proper handling of the disk change flag.
---
 Kernel/BlkDev/DskFDC.HC | 51 +++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 47 insertions(+), 4 deletions(-)

(limited to 'Kernel/BlkDev/DskFDC.HC')

diff --git a/Kernel/BlkDev/DskFDC.HC b/Kernel/BlkDev/DskFDC.HC
index 5b5105d..e9b0bdd 100644
--- a/Kernel/BlkDev/DskFDC.HC
+++ b/Kernel/BlkDev/DskFDC.HC
@@ -195,12 +195,12 @@ Bool FDCInit(CBlkDev *bd)
 
   recalibrate:
   // Recalibrate this drive
-  fdc_irq_semaphore=FALSE;
+  fdc_int_semaphore=FALSE;
   FDCSendByte(bd,FDC_RECALIBRATE);
   FDCSendByte(bd,bd->unit); // Drive number
 
   // Wait for an IRQ
-  while (!fdc_irq_semaphore) Yield;
+  while (!fdc_int_semaphore) Yield;
 
   // Get the result of the recalibration
   FDCSendByte(bd,FDC_SENSE_INTR);
@@ -224,7 +224,7 @@ U8 FDCWriteData(CBlkDev *bd,U8 cyl,Bool head,U8 start,U8 end)
   U16 length=(end-start+1)*bd->blk_size;
   U8 st0,st1,st2,pcn,hd,sect,size
 
-  fdc_irq_semaphore=FALSE;
+  fdc_int_semaphore=FALSE;
 
   FDCDMAInit(length);
   FDCDMAPrepWrite();
@@ -256,7 +256,7 @@ U8 FDCReadData(CBlkDev *bd,U8 cyl,Bool head,U8 start,U8 end)
   U16 length=(end-start+1)*bd->blk_size;
   U8 st0,st1,st2,pcn,hd,sect,size
 
-  fdc_irq_semaphore=FALSE;
+  fdc_int_semaphore=FALSE;
 
   FDCDMAInit(length);
   FDCDMAPrepRead();
@@ -369,4 +369,47 @@ U0 FDCWriteBlks(CBlkDev *bd,U8 *buf,I64 blk,I64 cnt)
     retries-=1;
     goto retry;
   }
+}
+
+U8 FDCReadId(CBlkDev *bd,Bool hd)
+{
+  U8 st0,st1,st2,c,h,r,n;
+  fdc_int_semaphore=FALSE;
+
+  FDCSendByte(*bd,FDC_READ_ID|bd->mfm<<6);
+  FDCSendByte(*bd,bd->unit|hd<<2);
+
+  while (!fdc_int_semaphore) Yield;
+
+  st0=FDCReadByte(*bd);
+  st1=FDCReadByte(*bd);
+  st2=FDCReadByte(*bd);
+  c=FDCReadByte(*bd);
+  h=FDCReadByte(*bd);
+  r=FDCReadByte(*bd);
+  n=FDCReadByte(*bd);
+
+  return st0>>6;
+}
+
+U8 FDCChk(CBlkDev *bd)
+{
+  // Check if there is a disk of the selected density in the drive
+
+  Bool unlock=BlkDevLock(bd),h0,h1;
+
+  FDCSelDrv(bd);
+
+  h0=!FDCReadId(bd,0);
+  h1=!FDCReadId(bd,1);
+
+  if (h0) {
+    if (h1) {
+      return FDC_CHK_DS;
+    } else {
+      return FDC_CHK_SS;
+    }
+  } else {
+    return FDC_CHK_ERR;
+  }
 }
\ No newline at end of file
-- 
cgit v1.2.3