DISKS AND DISK DRIVES
BBC->FAQ->Disk Search

  • How do I format disks?
  • How can I use a 3.5" disk drive on a BBC?
  • How do I wire up a disk drive data lead?
  • What is the Master Compact disk connector pinouts?
  • Twist
  • -> Will a twisted drive lead work with a BBC?
  • Osword62
  • -> LVFS OSWORD &62
  • Osword72
  • -> ADFS OSWORD &72
  • Osword7F
  • -> DFS OSWORD &7F
  • DFSOsword
  • -> Using DFS OSWORD commands
  • InstallDFS
  • -> Installing DFS
  • WD1770
  • -> WD1770 Floppy Disk Controller
  • ScanDir
  • -> How do I read the entries in a directory?
  • Format
  • -> Disk Formats
  • Densities
  • -> Disk Densities
  • Memory7F
  • -> Memory locations corrupted by OSWORD &7F
  • DFSMem
  • -> Memory used by Acorn DFS
  • ADFSSum
  • -> Calculate ADFS checksum
  • BBCDOCS Disks and Drives document
  • Can I use DOS disks?
  • Can I read Acorn format discs on a PC?
  • Disk formats
  • File systems
  • Disk filing systems
  • AuxPwr.gif
  • BBC aux power pinout
  • DskPwr.gif
  • Disk drive power connectors



    How can I format disks?

    DFS v0.xx and v1.xx do not have a format command built in, and neither does ADFS v1.xx. They are supplied with a format command on disk. The problem arises when you have no formatted disks to start with.

    There is a program here that is short enough to type in without errors which will format a DFS disk.

    DFS v2.xx and ADFS v2.xx contain format commands in ROM, and so do non-Acorn DFSs such as Watford DFS and extension ROMs such as Disc Doctor, Advanced Disc Investigator (ADI) and Advanced Disc Tools (ADT).



    How can I use a 3.5" disk drive on a BBC?

    Plug in the disk drive. Use.

    As far as a BBC is concerned, a disk drive is just a disk drive. It doesn't care what physical size the disk or drive is. You can use 5.24" 3.5" and 3" drives just by plugging them in.

    DFS 1.20 has some problems with 3.5" drives. It doesn't [[do something]] giving 'Disk error 10' (Drive not ready). This is easily solved by replacing DFS 1.20 with DFS 1.21. A patch program and a pre-patched ROM image is available on mdfs.net.

    Disk drives have a set of selection links or a small switch to select what drive number they are. DFS logical drives 0 and 2 and ADFS or HADS logical drive 0 access physical drive 0. DFS logical drives 1 and 3 and ADFS or HADFS logical drive 1 access physical drive 1.

    Some 3.5" drives are permanently wired as drive 1. It is possible, though fiddly, to modify these to be drive 0. When obtaining disk drives you should ensure they have drive select links or a switch.



    How do I wire up a disk drive data lead?

    You need a standard straight-through data lead. Pin 1 to 1, 2 to 2, 3 to 3, etc. No twists, no cut wires, no modifictions of any kind. All the connectors should be on the same side of the cable. With 3.5" drive connectors the lugs on the IDC headers must be on the same side along the cable. 5.25" and 3" drives use an unpolarised edge connector.

        **                                      **       **
    lug **                                  lug **   lug **
        ===================================================
    
    3.5" drives typically draw sufficiently little power that two 3.5" drives or one 5.25" and one 3.5" drive can be powered from the BBC model B auxilary power connector. The Master auxilary power connector can supply more power and can power two 5.25" drives.



    What is the Master Compact disk connector pinouts?

    You can connect disk drives to the Master Compact by simply making a through cable missing off the end wires. Odd numbered IDC pins connect to 25-D pins 14 to 25.

    25-D            34-IDC
                     2  1
                     4  3
                     6  5
        1---INDEX----8  7
    14  2---DS0-----10  9
    15  3---DS1-----12 11
    16  4---DS2-----14 13
    17  5---MOTOR---16 15
    18  6---DIR-----18 17
    19  7---SEEK----20 19
    20  8---DATA----22 21
    21  9---ENABLE--24 23
    22 10---TRK0----26 25
    23 11---WRPROT--28 27
    24 12---READ----30 29
    25 13---SIDE----32 31
                    34 33
    
    



    This page last updated 11-Aug-2006