From 1e73e8d8865069db107667436519cc5e7148dad3 Mon Sep 17 00:00:00 2001
From: Terence Boldt <terence@boldt.ca>
Date: Fri, 7 Jun 2024 18:30:08 -0400
Subject: [PATCH] Fix #170 driver crash on unload drive

---
 RaspberryPi/apple2driver/handlers/block.go | 7 ++++++-
 RaspberryPi/apple2driver/info/version.go   | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/RaspberryPi/apple2driver/handlers/block.go b/RaspberryPi/apple2driver/handlers/block.go
index 0ee8414..539e13f 100644
--- a/RaspberryPi/apple2driver/handlers/block.go
+++ b/RaspberryPi/apple2driver/handlers/block.go
@@ -22,7 +22,7 @@ func ReadBlockCommand(drive1 prodos.ReaderWriterAt, drive2 prodos.ReaderWriterAt
 	driveUnit, err = comm.ReadByte()
 
 	if err != nil {
-		fmt.Printf("Failed to read block")
+		fmt.Printf("Failed to receive requested block number")
 		return 0, err
 	}
 
@@ -34,6 +34,11 @@ func ReadBlockCommand(drive1 prodos.ReaderWriterAt, drive2 prodos.ReaderWriterAt
 		driveNumber = 2
 	}
 
+	if file == nil {
+		fmt.Printf("Requested drive not loaded")
+		return 0, err
+	}
+
 	slotNumber := driveUnit & 0x7F >> 4
 
 	block := int(blockHigh)*256 + int(blockLow)
diff --git a/RaspberryPi/apple2driver/info/version.go b/RaspberryPi/apple2driver/info/version.go
index 6b8aa97..beeef6c 100644
--- a/RaspberryPi/apple2driver/info/version.go
+++ b/RaspberryPi/apple2driver/info/version.go
@@ -8,4 +8,4 @@ package info
 
 // Version is the hexadecimal version number that
 // should be incremented with each driver update
-const Version = "002D"
+const Version = "002E"