Add comment about 2MG files

README-veserver.md

@@ -14,6 +14,11 @@ place of the ADTPro server for this purpose.  VEServer is a much smaller and
 simpler program, so it is easier to modify and better suited to being run as
 a system service.
 
+VEServer can also support RS232 serial connections, in which case ADTPro's
+`VSDRIVE.SYSTEM` should be used on the Apple II rather than `VEDRIVE.SYSTEM`.
+The default mode of operation is to use ethernet.  See the Command Line
+Options section below for information on how to switch to serial mode.
+
 ## Principle of Operation
 
 VEServer uses IPv6 and listens on UDP port 6502 for incoming datagrams from
@@ -24,7 +29,8 @@ VEServer uses IPv6 and listens on UDP port 6502 for incoming datagrams from
 
 Two simulated drives are supported, backed up by disk files in `.po` "ProDOS
 Order".  These may be 143K or 800K floppy disk images or any volume up to the
-ProDOS limit of 32MB.
+ProDOS limit of 32MB.  `.2mg` container files are also supported, provided
+the volume within the `.2mg` file is in ProDOS order.
 
 VEServer can provide system date and time in a similar manner to an Apple II
 clock such as Thunderclock or No Slot Clock.  Because the legacy ProDOS date
@@ -34,12 +40,19 @@ ProDOS 2.5 please specify the `--prodos25` flag to use the new format.
 
 ## Command Line Options
 
-There are only a few options:
+VEServer accepts the following command line options; each option has a short
+form and a verbose form:
 
  - `-h`, `--help` - Display brief usage information.
  - `-p`, `--prodos25` - Use new ProDOS 2.5 date/time format (see above.)
- - `-1 FNAME`, `--disk1=FNAME` - Specify filename for disk 1 image. 
- - `-2 FNAME`, `--disk2=FNAME` - Specify filename for disk 1 image. 
+ - `-1 FNAME`, `--disk1=FNAME` - Specify filename for disk 1 image.
+ - `-2 FNAME`, `--disk2=FNAME` - Specify filename for disk 1 image.
+ - `-s`, `--serial` - Use RS232 serial rather than Ethernet.
+ - `-b nnnnn`, `--baud=nnnnn` - Specify baud rate when using serial connection.
+
+If the `--disk1=FNAME` or `--disk2=FNAME` options are not specified, VEServer
+will fall back to using the default values hard coded at the top of the
+Python script.
 
 ## Running in a Shell
 
@@ -75,3 +88,28 @@ following command:
 Rather than using colour to indicate reads and writes the letter 'R' or 'W' is
 shown before the block number in the log.
 
+## Working with Multiple Apple II Clients (Advanced)
+
+If you use `VEDRIVE.SYSTEM` on more than one Apple II machine, it is sometimes
+convenient to be able to use different disk images on each machine.  VEServer
+offers a way to do this.
+
+Suppose the disk1 filename is set to `virtual-1.po` and the disk2 filename is
+set to `virtual-2.po` (either using the `--disk1=FNAME` / `--disk2=FNAME`
+command line parameters, or using the hard-coded default.)  Further, suppose
+the IP address of the Apple II client is 192.168.0.100.  In this case, when
+accessing drive 1, VEServer will first look for the file:
+
+ - `virtual-1-192.168.0.100.po`
+
+If this is found that file will be served.  If not found, VEServer will fall
+back to:
+
+ - `virtual-1.po`
+
+Similarly for drive 2, `virtual-2-192.168.0.100.po` will be used if it exists,
+or `virtual-2.po` otherwise.
+
+This mechanism allows you to serve different disk images for each client,
+allowing read/write access with no risk of data corruption due to simultaneous
+access.

veserver.py

@@ -11,8 +11,8 @@
 ###########################################################################
 
 pd25 = False   # Default to old-style date/time --prodos25 to use new format
-file1 = "/home/pi/virtual-1.po"  # Disk image drive 1 --disk1 to override
-file2 = "/home/pi/virtual-2.po"  # Disk image drive 2 --disk2 to override
+file1 = "/home/bobbi/virtual-1.po"  # Disk image drive 1 --disk1 to override
+file2 = "/home/bobbi/virtual-2.po"  # Disk image drive 2 --disk2 to override
 serial_port = None  # Serial port to use instead of ethernet
 baud_rate = 115200  # Baud rate for serial mode
 
@@ -107,10 +107,36 @@ def printinfo(drv, blknum, isWrite, isError, cs):
     prevop = isWrite
     prevcs = cs
 
+#
+# Augment filename by adding IP
+# If filename is basename.ext and IP is 192.168.2.3
+# will return basename-192.168.2.3.ext
+#
+def augment_filename(filename, ip):
+    idx = filename.rfind(".")
+    basename = filename[0 : idx]
+    ext = filename[idx:]
+    return basename + "-" + ip + ext
+
+#
+# See if augmented filename exists, if so return that name
+# otherwise return the unaugmented name
+#
+def select_filename(filename, ip):
+    if serial_port:
+        return filename
+    filename_with_ip = augment_filename(filename, ip)
+    try:
+        with open(filename_with_ip, "rb"):
+            pass
+    except:
+        return filename
+    return filename_with_ip
+
 #
 # Read block with date/time update
 #
-def read3(dataport, addr, d):
+def read3(dataport, addr, ip, d):
     global packet
 
     d = dataport.recvmore(d, 3)
@@ -124,6 +150,8 @@ def read3(dataport, addr, d):
        drv = 2
        skip = skip2
 
+    file = select_filename(file, ip)
+
     blknum = d[2] + 256 * d[3]
 
     err = False
@@ -164,12 +192,12 @@ def read3(dataport, addr, d):
     printinfo(drv, blknum, False, err, cs)
 
     b = dataport.sendto(bytearray(l), addr)
-    #print('Sent {} bytes to {}'.format(b, addr))
+    #print('Sent {} bytes to {}'.format(b, ip))
 
 #
 # Write block
 #
-def write(dataport, addr, d):
+def write(dataport, addr, ip, d):
     global packet
 
     d = dataport.recvmore(d, BLKSZ + 4)
@@ -183,6 +211,8 @@ def write(dataport, addr, d):
        drv = 2
        skip = skip2
 
+    file = select_filename(file, ip)
+
     cs = 0
     for i in range (0, BLKSZ):
          cs ^= d[i+5]
@@ -192,7 +222,7 @@ def write(dataport, addr, d):
     err = False
     if cs == d[517]:
         try:
-            with open(file, 'r+b') as f:
+            with open(file, 'rb') as f:
                 b = blknum * BLKSZ + skip
                 f.seek(b)
                 for i in range (0, BLKSZ):
@@ -220,7 +250,7 @@ def write(dataport, addr, d):
     printinfo(drv, blknum, True, err, cs)
 
     b = dataport.sendto(bytearray(l), addr)
-    #print('Sent {} bytes to {}'.format(b, addr))
+    #print('Sent {} bytes to {}'.format(b, ip))
 
 #
 # See if file is a 2MG and, if so, that it contains .PO image
@@ -332,7 +362,7 @@ for a, v in args:
     elif a in ('-b', '--baud'):
         baud_rate = int(v)
 
-print("VEServer v1.1")
+print("VEServer v1.2")
 if pd25:
     print("ProDOS 2.5+ Clock Driver")
 else:
@@ -347,11 +377,13 @@ with DataPort(serial_port, baud_rate) as dataport:
     while True:
         try:
             data, address = dataport.recvfrom(2)
-            # print('Received {} bytes from {}'.format(len(data), address))
+            ip = address[0]
+            ip = ip[ip.rfind(":")+1:]
+            #print('Received {} bytes from {}'.format(len(data), ip))
             if (data[0] == 0xc5):
                 if (data[1] == 0x03) or (data[1] == 0x05):
-                    read3(dataport, address, data)
+                    read3(dataport, address, ip, data)
                 elif (data[1] == 0x02) or (data[1] == 0x04):
-                    write(dataport, address, data)
+                    write(dataport, address, ip, data)
         except DataPort.Timeout:
             pass