Master/slave system for replicating/formatting flexible magnetic diskettes

A system for making duplicate copies of pre-recorded flexible diskettes, comprising in combination:

• (a) a master module including
• (1) a mass storage device for storing binary encoded data signals including the words representing the image of the information to be duplicated;
• (2) microprocessor means having random access memory means associated therewith for storing a program of instructions for controlling operation of said mass storage device,
• (3) translator means coupled in communication with said mass storage device for converting said binary encoded data signals to flux transition representations of said data,
• (4) further memory means coupled to the output of said translator means for temporarily storing, in sequence, the flux transition representations for words to be recorded on a single track of a flexible diskette,
• (5) programmable timing means coupled to said microprocessor means,
• (6) parallel-to-serial converter means coupled to receive said flux transition representations of words in parallel and to produce a serial train of said flux transition representations under control of said programmable timing means;
• (b) slave module means including
• (1) drive means for rotating a diskette to be recorded upon at a controlled rate, said drive means including means for producing an index pulse upon each revolution of said diskette,
• (2) transducing means positioned in recording relationship to said diskette,
• (3) means responsive to said index pulse for stepping said transducing head to a different track position,
• (4) write current generating means connected to said transducing head and coupled to receive said serial train of flux transition representations for recording same on said diskette;
• and
• (c) a bidirectional, serial data bus having data line means coupling said parallel-to-serial converter means in said master module and said write current generating means in said slave module means and at least one control line for coupling said index pulses from said slave module to said programmable timing means and said microprocessor means whereby said microprocessor means maintains synchronization of the transfer of information to be recorded over said data lines means.

In a system for recovering data from a magnetic recording member containing recorded information in the form of a self-clocking code, data separating means comprising in combination:

• (a) means for reading flux transition peak signals from a magnetic recording member;
• (b) a source of reference clock signals of a frequency nominally equal to the frequency of the clock encoded in said self-clocking code for defining a time window;
• (c) means coupled to said source of reference clock signals for dividing said time window into a plurality of generally equal time segments;
• (d) data synchronizing means for synchronizing said flux transition peak signals with said segments;
• (e) presettable counting means coupled to said data synchronizing means and to said means for dividing for adjusting the length of said time window segments;
• and
• (f) phase correction logic means coupled to said presettable counting means for periodically entering a digital quantity into said presettable counting means under control of said data synchronizing means whereby a predetermined count value is accumulated in said presettable counting means in synchronism with the occurrence of said flux transition peak signals.

A system for recovering the data from a self-clocking encoded data pattern comprising:

• (a) a source of reference clock signals of a nominal frequency corresponding to the frequency of the clock encoded in said self-clocking encoded data pattern for defining a timing window;
• (b) means for dividing said timing window into a predetermined number of equal segments;
• (c) data synchronizing means for synchronizing said segments of said timing window with said encoded data pattern;
• (d) counter means coupled to said data synchronizing means and to said means for dividing said timing window into a predetermined number of equal segments for shifting said timing window to maintain a desired relationship between said timing window and said encoded data pattern;
• and
• (e) gating means coupled to receive the output from said data synchronizing means and controlled by said counter means for producing a return-to-zero data pattern at the output of said gating means.

A system for replicating information patterns recorded on a magnetic surface, comprising:

• (a) master module means including a programmable microprocessor having a central processing unit, a random access memory coupled to said central processing unit for storing a program of instructions and data-representing signals at addressable locations therein and first bi-directional transceiver means coupled to said random access memory means and to said central processing unit;
• (b) a plurality of slave module means, each including:
• (1) drive means for moving said magnetic surface of each relative to an associated magnetic transducing means in synchronism with the magnetic surface of the other of said drive means, (2) read circuit means coupled to said magnetic transducing means for producing flux transition signals in accordance with the information patterns recorded on said magnetic surface, (3) write circuit means coupled to said magnetic transducing means for recording flux transition signals in accordance with a predetermined encoding scheme on said magnetic surface, and second bi-directional transceiver means coupled to said read circuit means and said write circuit means;
• (c) a multi-conductor cable connecting said first bi-directional transceiver means in said master module to said second bi-directional transceiver means in each of said plurality of slave module means for selectively carrying said data representing signals, said flux transition signals and control signals, including slave module addressing signals, between said master module and said plurality of salve module means;
• (d) identifier means for uniquely identifying said slave module means from one another;
• and
• (e) comparator means coupled to said identifier means and connected to receive slave module addressing signals originating at said cental processing unit in said master module via said multi-conductor cable whereby predetermined ones of said plurality of slave module means are selected for communication with said master module.