Abstract:
A system for the duplication of binary data onto CD-R disks, the system including a copy unit, a host computer and computer software, the software being installed in the host computer to provide a user interface and to direct the transfer of data from the host computer to the copy unit, the copy unit including a set of multiple stacked recordable disk drives, a set of stacked disk spindles, each spindle affixed to a motorized tray, a transport tower, a printer, and a microprocessor. A robotic disk pickup head on the transport tower is connected to the transport tower with an elevator mechanism for lifting and transporting compact disks. The motorized trays move the disk spindles between a holding location and a transport axis, the transport axis being a vertical line that intersects the center of the robotic disk pickup head. The stacked recordable disk drive trays and printer also receive and eject disks along the transport axis, allowing for the robotic disk pickup head to transport disks from any disk spindle to any stacked recordable disk drive or the printer. The microprocessor concurrently directs the movement of the disk pickup head and the copying of data to the CD-R disks. The system allows for source data to be read from multiple master compact disks inserted in specified stacked recordable disk drive members to provide for random access copying from the multiple master compact disks.

Description:
BACKGROUND OF THE INVENTION 
     This application claims priority of provisional application No. 60/040,422 filed Mar. 13, 1997. 
    
    
     Digital compact disks were originally conceived in the early 1980&#39;s as a technique to accurately copy and preserve audio recordings intended for sale to a mass market of consumers. As computing power has increased exponentially since that time, information processing tasks unthinkable only a few years ago have become commonplace and require large amounts of data most economically and conveniently stored on digital compact disks. 
     Until recently the transfer of data onto compact digital disks was a costly procedure economically feasible only when manufacturing a large quantity of copies. Users whose applications required relatively few copies or required frequent data updates could not reap the benefits of this technology, even though low-cost disk-readers were readily available. 
     The advent of recordable digital compact disks, generally referred to as “CD-R” disks, was intended to allow users to record their own disks and thereby achieve significant savings. Unlike a common compact disk that has been pressed by a mold, a CD-R has a dye layer that is etched by a laser contained in the CD-R disk drive. Once etched, the “burned” CD-R disk is unalterable and will retain data for approximately 75 years. 
     Several practical problems have prevented CD-R users from attaining maximal efficiency in the copy process, especially when attempting to make multiple disk copies in a short amount of time. The primary problem occurring in this situation is that the data throughput from the data source, such as a file on a hard disk drive or a master compact digital disk, to the write head of the CD-R drive is interrupted during the copy process. Many times when this occurs the data buffer to the write head of the CD-R drive is exhausted and null data is written onto the CD-R disk, making the CD-R disk irrevocably defective. 
     The frequency of such a defective CD-R disk write increases at least linearly as the drive speed of the CD-R writing head is increased. The industry standard speed is approximately 150K Bytes per second. Some CD-R disk drives can write data at four times this standard speed, but while this increased speed lowers the total copying time, the frequency of defective CD-R disk writes increases as data throughput from the data source is increased. 
     An additional problem in a volume copying process is the necessity for direct human supervision to prepare CD-R disks for copying, remove the disks from the CD-R disk writer once copying is complete, and then prepare the disks for inspection to ensure no defective CD-R disks are retained in the completed set of copies, and if desired, to label the burned CD-R disks. Aside from the tedium involved that may indirectly add errors, requiring human attention in this process adds a significant labor cost that is added to the end-user price. 
     The copy speed versus accuracy problem described above is solved when the CD-R disk writer is configured to concurrently copy the data onto multiple CD-R disks. For example, the total copy time for two CD-R disk drives concurrently copying data at 150 K Bytes per second is the same as one CD-R disk drive serially copying two CD-R disks at 300K Bytes per second, and the frequency of disk write errors using the concurrent disk drives is approximately half that of the serial disk drive. 
     This system uses the concurrent copying method described above and also eliminates the necessity of direct human supervision of the copy process through the unique arrangement of CD-R disk spindle members affixed to motorized trays, the motorized trays transporting the disk spindle members along a transport axis formed by the vertical line passing through the center of a robotic disk pickup head. 
     The system additionally comprises a set of vertically stacked recordable disk drive members, each disk drive member having a tray loader that receives and ejects disks along the transport axis, allowing for a transport tower containing a disk pickup head to lift a blank disk from a disk spindle member and transports the disk to one of the available stacked CD-R disk drives. After the recording process is complete the disk pickup head retrieves and transports the burned CD-R disk copy to a specified disk spindle member for copied disks. 
     The electrical and physical configuration of this system provides several additional benefits to users. The arrangement of disk spindle members and recordable disk drive members about the transport axis minimizes the number of moving parts needed to construct the disk transport assembly. This configuration also allows the system to be constructed of discrete modules that can be shipped separately and easily assembled by the user, and also allows for rapid repairs by removal of a malfunctioning module and replacement with a functional module. 
     Prior disk copy methods only provided for lineal copying of a single source disk. The configuration of this system allows for several master compact disks to be transportable by the transport tower to a selected disk read head so that the copy process from the master compact disks is a random access process. 
     Yet another benefit provided by this system is the system&#39;s ability to test burned CD-R disks for disk write errors, and place defective CD-R disks on a specified disk spindle member, thus isolating the defective CD-R disks from the set of properly burned CD-R disks. 
     SUMMARY OF THE INVENTION 
     The programmable, automatic compact disk duplication system of this invention includes a copy unit, a host computer, and computer software. The host computer and computer software provide an interface allowing the user to pre-program the copy unit to perform a completely unattended copy and data verification operation upon blank CD-R disks pre-loaded in the copy unit. 
     While not required for operation of the duplication system, it is preferred that the duplication system use an IBM PC-clone running a DOS or Windows operating system so that users need not purchase additional computer hardware to operate the duplication system. Hardware-specific computer components necessary to describe the duplication system will reference IBM PC and Windows specifications; however the duplication system is not intended to remain limited to these specifications and a designer skilled in the art would be able to translate these specifications into hardware and software equivalents for systems using Apple, UNIX, or IBM protocols. 
     The Copy Unit 
     The copy unit has a main copy assembly with an external vacuum pump. The primary components inside a housing for the main copy assembly include a microprocessor, a set of disk spindle members with each member affixed to a motorized tray, a transport tower, a data transfer unit, a vacuum regulator and an air filtration unit. The external vacuum pump is connected to the vacuum regulator by an air hose leading to a disk suction pickup unit affixed to the transport tower. 
     1. The Microprocessor 
     The microprocessor is an internal control unit for the copy unit and is electrically connected to the host computer, the transport tower, the motorized tray members, and all CD-R disk drive heads. In the preferred embodiment, a 8031 microprocessor is used, but any 8-bit microprocessor capable of processing a command set of about 20 commands could be used. 
     The microprocessor receives user input generated by the software that is executed on the user&#39;s host computer. The computer software processes the user input into a set of ASCII commands sent to microprocessor via an RS-232 interface. The ASCII command set used is a variant of the Trace Mountain protocol that is often used to interface software to hardware copy devices. Commands sent by the computer software to the microprocessor consist of one letter or one letter and two digits. Once the microprocessor is sent a command by the host computer, the microprocessor parses the command and sends an electrical signal to the transport tower. 
     Depending on the command sent by the computer software, the microprocessor will transmit back to the computer software a “ready” indication, an echo of the command received, or a status indication that command received was successfully or unsuccessfully executed. This status indication is then interpreted by the computer software into user readable information displayed on the host computer&#39;s video output display. 
     2. The Disk Spindle Members 
     A set of disk spindle members are stacked vertically inside the housing of the copy unit. The bottom of each disk spindle member is affixed to a horizontal motorized tray member and projects vertically from the tray member. The diameter of each disk spindle member is slightly smaller than the center hole of a CD-R disk, allowing for free vertical movement of the CD-R disk when the disk is located on the disk spindle member. 
     The horizontal motorized tray members are spaced vertically a distance greater than the height of each disk spindle member, allowing for free travel of the disk spindle member when the motorized tray members travel horizontally. It is expected that at least two disk spindle members are located in the housing of the copy unit, allowing one disk spindle member to hold blank CD-R disks and the other disk spindle member to hold burned CD-R disks. 
     3. The Transport Tower 
     The transport tower is located on the inside wall of the housing opposite the disk spindle members. The transport tower has two vertical supports with a vertical belt positioned between the vertical supports. One end of the vertical belt passes around a pulley wheel affixed to the inside wall of the housing close to the top inner wall of the housing. 
     The other end of the vertical belt passes around a set of pulley wheel gears that are connected to a motor that causes the belt to rotate when the motor is engaged. Control of the motor is supplied by electrical signals sent by the microprocessor. 
     An arm for a disk pickup head projects horizontally from the transport tower. One end of the arm is affixed to the belt and has apertures allowing the vertical supports to pass through and support the arm. When the motor rotates the belt, the arm is raised or lowered depending on the direction of rotation of the belt. 
     The other end of the arm supports a disk pickup head which has a disk suction pickup unit. The disk suction pickup unit is triangle-shaped and has a circular aperture located at its apex. The diameter of the aperture is slightly wider than the diameter of a disk spindle member and travels along a vertical line forming a transport axis as the arm is raised or lowered. 
     Located on the underside of the disk suction pickup unit near each vertice of the disk suction pickup unit is one suction member and one rubber stopper member. A sensor also protrudes downward from the underside of the disk suction pickup unit and relays an electrical signal back to the microprocessor indicating the presence of a target disk near the disk suction pickup unit. 
     Additionally, during operation of the disk suction pickup unit, RAM memory located in the microprocessor or electrically connected to the microprocessor retains data for each disk spindle member corresponding to the approximate vertical distance the disk suction unit must travel before retrieving a blank CD-R disk or placing a burned CD-R disk back onto the disk spindle member. 
     When the disk suction pickup unit is operated, the suction members draw in air, causing the target disk to adhere to the suction members. 
     The size and placement of the arm and the disk suction pickup unit are chosen so that during a disk pick-up or drop-down operation from a selected disk spindle member, the motorized tray affixed to the selected disk spindle member is configured in its extended position, and the selected disk spindle member passes through the aperture of the disk suction pickup unit. 
     In a typical disk transport operation, the microprocessor issues a sequential set of electrical signals that are translated into a sequential set of operations performed by the motor, the motorized trays on the stacked recordable disk drive members and supporting the disk spindle members, and the disk suction pickup unit. For example, the following sequential operations controlled by the microprocessor occur when the copy unit transfers the top CD-R disk from a stack of CD-R disks surrounding a selected spindle to the disk suction pickup unit: 
     the motor raises the disk suction pickup unit to a height such that all components of the disk suction pickup unit are above the top of the selected disk spindle member; 
     the motorized tray affixed to the selected disk spindle member extends outward so that the selected disk spindle member lies along the transport axis; 
     1) the motor lowers the disk suction pickup unit along the disk spindle member until the suction members make contact with the CD-R disk; 
     the suction members engage and hold the CD-R disk; 
     the motor raises the disk suction pickup unit along the disk spindle member until the CD-R disk held by the suction members is above the top of the selected disk spindle member; 
     the motorized tray affixed to the selected disk spindle member retracts, allowing the disk suction pickup unit to travel freely along the transport axis. 
     4. The Data Transfer Unit 
     The data transfer unit comprises a set of stacked disk drive receptacle members and a variable number of stacked recordable disk drive members. The stacked disk drive receptacle members are stacked vertically inside the housing of the copy unit at right angles to both the disk pickup head and the disk spindle members. Each stacked recordable disk drive member fits in a slotted receptacle member located in one of the disk drive receptacle members and is positioned so that the extended position of each loading tray member for all stacked recordable disk members places the center of a loaded disk along the transport axis. This positioning allows the disk pickup head to insert or remove a CD-R disk from any stacked recordable disk drive member. 
     Each stacked recordable disk drive member sends and receives binary data with the computer software via a standard 50-pin SCSI connection between the stacked recordable disk drive member and the host computer. Loading and unloading of a CD-R disk in every stacked recordable disk drive member is accomplished through control of the loading tray member communicated through each stacked recordable disk drive member&#39;s SCSI connection. 
     In the preferred embodiment, a disk printer may be inserted above the stacked recordable disk drive members, allowing for the printing of symbols on the top side of CD-R disks before or after the copy operation. In this embodiment, the disk printer has a standard loading tray that when extended places the center of a loaded CD-R disk along the transport axis. The printer is placed below the top height of the disk pickup head so that the disk pickup head may load and unload disks from the loading tray of the printer. 
     An additional feature of the preferred embodiment is software control allowing for inspection of each burned CD-R disk for copy errors and control for placing defective burned CD-R disks onto a specified disk spindle member. 
     5. The Vacuum Regulator and the External Vacuum Pump 
     The vacuum regulator is housed inside the main copy assembly and is connected to the suction members by an air hose. An external air hose connects the vacuum regulator to the external vacuum pump that is physically separated from the main copy assembly in order to reduce vibrations inside the main copy assembly. The vacuum regulator maintains a constant pressure vacuum and is controlled by the microprocessor. 
     6. The Air Filtration Unit 
     The air filtration unit creates a flow of filtered air through the inside of the main copy assembly to significantly reduce CD-R disk read or write errors caused by dust or other contaminants that may be in the air surrounding the duplication system. The air filtration unit comprises a set of electric fan members, an air filter, a set of outflow vents, and an outer cover covering the outside of main copy assembly. The electric fan members are positioned along the back vertical face of the main copy assembly and when operated draw air into the inside of the main copy assembly. 
     Positioned along the inside vertical face of the main copy assembly is an air filter that filters air drawn in by the electric fan members before it can circulate through the inside of the main copy assembly. The filtered air then exits the main copy assembly through the outflow vents. 
     The Host Computer 
     No particular type of host computer is necessary to support the copy unit and the computer software. A conventional personal computer equipped with a SCSI throughput interface and a hard disk drive capable of retaining an image of the master data will suffice. 
     The Computer Software 
     In the preferred embodiment, the computer software necessary to direct the data transfer operations is written in the “C” programming language running under a Windows operating system. However, the computer software could be written using any computer language and operating system compatible with the computer used, provided Trace Mountain—type protocols can be sent to the copy unit via an RS-232 or SCSI connection between the host computer and the copy unit. 
     These and other features will become apparent from a consideration of the Detailed Description of the Preferred Embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of the compact disk duplication system of this invention with a front view of the copy unit. 
     FIGS. 2A-2E are continuous flowchart diagrams of the procedures performed in a disk copy operation. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, the programmable automatic compact disk duplication system of this invention is designated generally by the reference numeral  10 . The duplication system  10  includes a host computer  12 , shown schematically, connected to a copy unit  20 . The host computer  12  comprises a programmable computer that includes computer software for providing a user interface for operating the copying process of the copy unit  20 . It is to be understood that the host computer may be incorporated into the copy unit  20  with the copy unit having a keyboard or other input device such as a control panel for managing the operation of the copy unit  20 . 
     The copy unit  20  includes an internal microprocessor  24  that is electrically connected to the host computer  12  for controlling the electromechanical operations of the copy unit  20 . The copy unit  20  is constructed with a housing  14  having two opposing inner walls  16  and  22 , a rear wall  18 , and a deck  17  for supporting the electronics and drive assemblies. 
     A set of motorized tray members  26  are affixed to the inner wall  16  and extend horizontally towards the center of the space enclosed by housing  14 . The motorized tray members  26  are electrically connected to the microprocessor  24  by a line  28  that sends a signal to each motorized tray member  26  to engage an inner motor member  30  that extends or retracts tray members  32 . The illustration shown FIG. 1 depicts tray members  32   a  in their retracted position and tray member  32   b  in its extended position. 
     A removable disk spindle member  34  is connected to the top of each tray member  32  and holds CD-R disk members  36 . A stationary disk spindle  38  is affixed to the deck  17  and serves as a holding receptacle for master disks, for additional CD-R disks, or for defective burned CD-R disks. 
     A set of stacked recordable disk drive members  42  are affixed to rear wall  18  and have disk drive tray members  48  that when extended protrude horizontally from the stacked recordable disk drive members  42  and towards the center of the space enclosed by housing  14 . The recordable disk drive members  42  are electrically connected to the microprocessor  24  by a line  44  that sends signals to each recordable disk drive member  42  to operate the recordable disk members  42 . 
     In its preferred embodiment the copy unit  20  includes a disk printer  50  that is affixed to rear wall  18  and has an input tray  52  that when extended protrudes horizontally from the disk printer  50  and towards the center of the space enclosed by housing  14 . The printer  50  is electrically connected to the microprocessor  24  by a line  51  that sends signals to the printer  50  to control its operation. 
     Additionally, a disk holding area  54  is affixed to rear wall  18  and serves as a temporary holding area  54  for CD-R disks that are manually stored or removed by the user. 
     Affixed to the deck  17  and inner wall  22  is a motor  56  that rotates a gear  58  when engaged. The motor  56  is electrically connected to the microprocessor  24  by a line  60  that sends signals to activate the motor  56 . Surrounding the gear  58  is a belt  62  that travels vertically along the inner wall  22  and wraps around a pulley wheel  64  that is affixed to the rear wall  18 . 
     Affixed to the outer surface of the belt  62  that faces toward the center of the space enclosed by housing  14  is a horizontal arm  66  having a vertical aperture  68  located in the center of the horizontal arm  66 . The underside of the horizontal arm  66  has three suction members  70  (two visible) creating sufficient suction to hold one disk against the underside of the horizontal arm  66 . 
     A vacuum hose  72  connects to the suction members  70  and runs along inner wall  22  where it connects with vacuum regulator  74 . The vacuum regulator  74  is connected to an external hose  76  that is connected to an external vacuum pump (not shown). The vacuum regulator  74  is electrically connected to the microprocessor  24  by a line  78  that sends signals to activate the vacuum regulator  74 , allowing for a suction force to appear at the end of the suction members  70 . 
     A female power receptacle  80  allows for attachment of an electrical cord (not shown) providing standard 120V AC to a transformer  82 . The transformer  82  supplies power to components throughout the main copy assembly  20 . 
     Located on the rear wall  18  are one or more electric fan members  86  that draw in air to ventilate the main copy assembly  20  and prevent heat build-up. An air filter  88  is positioned behind the electric fan members  86  and filters the air drawn in by the electric fan members  86  before the air travels through the interior of the main copy assembly  20 . The filtered air then exits the interior of the main copy assembly  20  through vent members  90  located on inner wall  16 . 
     In the preferred embodiment of FIG. 1, the copy unit  20  has three disk spindle members  34 . In such a configuration disk spindle member  34   a  hold s blank CD-R disks, disk spindle member  34 b holds burned CD-R disks, and disk spindle member  34   c  holds defective burned CD-R disks. The stationary disk spindle  38  is designated as the disk spindle member holding one or more master compact disks. 
     Referring to FIGS. 2A through 2E, a flowchart of the procedures performed in a disk copy operation, are shown beginning with START in item step  190 . The logic necessary to perform a disk copy operation is programmed into the computer software on the host computer and programmed into the microprocessor located inside the copy unit. 
     A user begins a disk copy operation by loading master disks on stationary disk spindle  38  (also designated as the master disk spindle) and loading blank recordable disks onto disk spindle member  34   a . The user then supplies power to the copy unit  20  and starts the computer software located in the host computer  12 . These initialization subprocedures are indicated in item step  200 . A display  13  connected to the host computer  12  then prompts the user for information regarding the selection of the disk spindle members for the blank and burned CD-R disks. The user also selects a disk output spindle that will temporarily hold master disks after the data transfer from each master disk to the host computer  12 . The user also supplies instructions indicating the tracks on the master disks to be copied. This operation is indicated in item step  210 . 
     When first powered on, the internal microprocessor  24  sends electrical signals to test the operation of the arm  66 , as indicated in item step  220 . The microprocessor  24  sends a set of flags back to the computer software to signal the status of the hardware located on the copy unit  20 , as indicated in item step  230 . If the computer software receives a status flag indicating hardware failure, the computer software issues a display error message for the user to decode, and the copy process is terminated, as indicated in item step  240 . 
     If the computer software receives status flags indicating the hardware is operational, the computer software sends instructions to the microprocessor that comprise a data acquisition subprocedure. The beginning of the data acquisition subprocedure is indicated in item step  250  and comprises item steps  260  through  340 . 
     In item step  260 , the computer software checks if a disk drive on the host computer contains an image of the master data. If an image file already exists, control of the software is transferred to item step  360 . Otherwise, control of the computer software is transferred to item step  270 . 
     As indicated in item step  270 , the computer software first compares the number of disk drives to the number of master disks loaded on master disk spindle  38 . If the number stacked recordable disk drive members  42  is greater than or equal to the number of master disks, the computer software sends a command set to the microprocessor  24  to transfer each master disk to an available stacked recordable disk drive  42 , as indicated in item step  280 . 
     The computer software then sequentially issues read commands to each stacked recordable disk drive member  42  containing a master disk and transfers the source data from each master disk to the host computer  12 . These commands are summarized in item step  290 . Once the data transfer process is completed, the computer software sends a command set to the microprocessor to transfer each master disk back to the master disk spindle  38 , as indicated in item step  300 , and the data acquisition subprocedure is complete. 
     If the number of stacked recordable disk drives  42  is less than the number of master disks, the computer software must loop through item steps  310  through  340  until all master disks have been transferred to an available stacked recordable disk drive  42 . 
     This loop begins when the computer software sends a command set to the microprocessor  24  to transfer the maximum number of remaining uncopied master disks held by the master disk spindle  38  to the stacked recordable disk drive members  42 , as indicated in item step  310 . Then in item step  320 , data is transferred from the master disks to the host computer  12  in the same manner as in item step  280 . 
     After all data from the master disks loaded in stacked recordable disk drives  42  has been transferred to the host computer  12 , the master disks are temporarily transferred to a disk spindle member spindle  34  as indicated in item step  330 . 
     The computer software completes this loop as indicated in item step  340  by comparing the number of uncopied master disks with zero, and returning to the top of the loop at item step  310  if any uncopied master disks remain. Once the data acquisition subprocedure is completed, all master disks are transferred back to the stationary disk spindle member  38 , as indicated in step  345 , and control of the computer software is transferred to the beginning of the data transfer subprocedure, indicated as item step  360 . 
     At the beginning of the data transfer subprocedure, the computer software will, if necessary, reformat the image of the source data located on the hard drive of the host computer to ensure optimal recording speed and accuracy. This computation is indicated in item step  370 . Item box  375  contains a comment for the following steps. A variable containing the number of copies made is initialized to zero, as indicated in item step  380 . 
     Item steps  390  through  430  correspond to a loop over all selected stacked recordable disk drive members  42  whereby the computer software first issues commands to the microprocessor  24  to query the hardware status of each stacked recordable disk drive member  42 , as indicated in item step  400 . The computer software will alert the user of any stacked recordable disk drive member  42  that the microprocessor  24  has identified as non-operational, as indicated in step  410 . Otherwise, the computer software will set a flag indicating that the queried CD-R drive is operational, as indicated in item step  420 . 
     Once the hardware test loop is completed, the computer software branches on a test of the number of operational stacked recordable disk drive members  42 , as indicated in item step  440 . The computer software will exit the copy process if no stacked recordable disk drive members  42  are operational, as indicated in item step  450 . Otherwise, the computer software initializes to zero a variable containing the number of copies made, as indicated in item step  460 . 
     The computer software then enters a main copy loop, indicated in item step  470 , that repeats until the number of copies made equals the desired number of copies. This comparison operation is made in item step  480 , and the proper termination of the copy process occurs in item step  490 . 
     If the number of copies made is less than the number of copies desired, the computer software initializes to zero a variable containing the number of copies currently loaded in the stacked recordable disk drive members  42 , as indicated in item step  500 . The computer software then enters an inner loop comprising item steps  510  through  580 , with each cycle of the inner loop corresponding to the transfer of a blank disk to an available operational stacked recordable disk drive member  42 . 
     This inner loop begins with a comparison of the number of copies desired with the sum of the copies already made plus the number of disks loaded the current batch transfer, as indicated in item step  520 . If the sum of the copies already made plus current number of disks loaded into the stacked recordable disk drive members  42  equals the number of copies desired, the inner loop terminates, as indicated in item step  530 . 
     Otherwise, the computer software issues a set of commands to the microprocessor  24  to transfer a blank disk to the next available stacked recordable disk drive member  42 , as indicated in item step  540 . The computer software then checks the status of the disk transfer, as indicated in item step  550 , and will terminate or otherwise commence other error handling subprocedures if the disk transfer failed, as indicated in item step  560 . Otherwise, the variable containing the number of disks loaded is incremented by one, as indicated in item step  570 . 
     Once the inner loop terminates at item step  580 , the stacked recordable disk drive members  42  have been loaded with the maximum number of blank disks, the computer software sends electrical signal instructions that activate the physical transfer of source data to each blank disk loaded in the loaded stacked recordable disk drive members  42 , as indicated in item step  590 . The computer software then examines copy status flags from each loaded stacked recordable disk drive member  42 , as indicated in item step  600 , and issues a command set to the microprocessor  24  to discard burned CD-R disks corresponding to any bad copy status flags, as indicated in item step  610 . 
     In item step  620 , the user can optionally configure the computer software to perform a data verification on each burned disk that is currently loaded in the stacked recordable disk drive members  42 . In this subprocedure, the computer software would direct each stacked recordable disk drive member  42  to read the data off the burned disk and compare it to the source data residing on the hard drive of the host computer  12 . Defective burned CD-R disks would be transferred to disk spindle member  34   c  as indicated in item step  610 . 
     In item step  630 , the user can optionally configure the copy unit to include a print application unit that imprints or labels the top of each burned CD-R disk with information transferred from the computer software. In this subprocedure, the burned CD-R disk is ejected from its stacked recordable disk drive member  42  and vertically transported by the arm  66  and then loaded into the input tray  52  of the printer  50 . After imprinting, the burned CD-R disk is transported to a disk spindle member  34  in the manner described above. 
     The variable containing the number of loaded stacked recordable disk drives is reset to equal the number of properly burned CD-R disks, as indicated in item step  640 . The total number of copies made is then incremented by the number of properly burned CD-R disks, as indicated in step  650 . The computer software then issues a command set to the microprocessor  24  directing the transfer of the properly burned CD-R disks to one of the designated output spindles, as indicated in step  660 . The computer software receives a status signal from the microprocessor  24  indicating whether the transfer occurred properly, as indicated in item step  670 , and will display an error message and exit if a disk transfer failed, as indicated in step  680 . Otherwise, control of the computer software drops to the bottom of the main loop  690  and then returns to the top of the main loop at item step  470 .