{"id":986,"date":"2016-08-01T13:14:35","date_gmt":"2016-08-01T13:14:35","guid":{"rendered":"http:\/\/avitech.com.au\/?page_id=986"},"modified":"2016-08-01T13:19:06","modified_gmt":"2016-08-01T13:19:06","slug":"transferring-rx01-discs-to-simh","status":"publish","type":"page","link":"https:\/\/avitech.com.au\/?page_id=986","title":{"rendered":"Transferring RX01 discs to SIMH"},"content":{"rendered":"

Dave Dunfield’s ImageDisk software includes two utilities that are very useful for moving a real RX01 disk to a virtual disk file that can be used with the SIMH PDP-11 simulator.<\/p>\n

To transfer a real RX01 disc to SIMH, use this process:<\/p>\n

    \n
  1. Put the RX01 disc in an 8-inch floppy drive attached to an MSDOS machine that has the ImageDisk programs installed<\/li>\n
  2. Use the main ImageDisk program (IMD.COM) to “read” the disc and store it as an IMD disk image. Let’s call it “ORIGINAL.IMD”<\/li>\n
  3. On the MSDOS machine, use IMDU.COM to convert the IMD disk image to a BINARY disk image, as follows: IMDU ORIGINAL.IMD ORIGINAL.DSK \/B<\/li>\n
  4. Now transfer the .DSK file to the machine that you run SIMH on. Hint: Setting up the mTCP package on your MSDOS machine and vsftp on a Linux machine will provide a super-fast and reliable way to transfer disk images between your machines<\/li>\n<\/ol>\n

    Let’s assume your RX01 disc was a bootable RT-11 disc. A suitable SIMH.INI file to boot your RX01 disc in SIMH is as follows:<\/p>\n

    \r\nset cpu 64k\r\nset cpu 11\/23\r\nset throttle 10%\r\nat rx0 original.dsk\r\nset tti 8b\r\nset tto 8b\r\nset console telnet=2222\r\nboot rx0\r\n<\/pre>\n
    You should now be able to fire up SIMH, and connect a console to SIMH using a Telnet terminal emulator (Hint: Use PuTTY and connect via the Telnet protocol to IP address 127.0.0.1 port 2222).<\/p>\n
    If your RX01 disc was bootable, you should now see RT-11’s boot messages and the familiar RT-11 dot-prompt in the terminal emulator.<\/p>\n
    Once you’ve finished making changes to your RX01 disc in SIMH, press CTRL-E in the SIMH window to return to the SIMH prompt. Type exit and press return to exit SIMH. Now rename your DSK file as “changed.dsk”.<\/p>\n
    To transfer the DSK file back to a real RX01 disk, use this process:<\/p>\n
      \n
    1. Transfer the DSK file back to your MSDOS machine that has ImageDisk on it (Hint: consider using the FTP technique described above to do this)<\/li>\n
    2. On the MSDOS machine, use BIN2IMD.COM to convert the BINARY disk image to an IMD disk image as follows: BIN2IMD CHANGED.DSK CHANGED.IMD N=77 DM=0 SS=128 SM=1-26 \/1 \/C<\/li>\n
    3. Use the main ImageDisk program (IMD.COM) to “write” the IMD disk image to a real 8-inch floppy disc connected to the MSDOS machine<\/li>\n
    4. Move the floppy disc to the RX01 drive on your PDP-11, and boot the PDP-11 with it<\/li>\n<\/ol>\n
      A few things to note about this process:<\/p>\n