Method of modifying a disk drive from serial to parallel operation

A disk drive that is the product of modifying a standard computer disk drive to read and write data in parallel with all of its transducer heads at once, rather than serially with only one head at a time. A method and apparatus are disclosed for protecting the disk drive's platters from damage and contamination while working on the interior of the disk drive case. The apparatus includes a hinged cover that replaces a conventional disk drive cover while work is being performed on circuitry within the disk drive case. The hinged cover seals off the platters and the inside of the disk drive case except for the circuitry being worked on.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to computer disk drives, and more 
particularly, to an apparatus and method for use in modifying disk drives. 
2. Description of the Related Art 
Video image processing is currently a rapidly growing field in which vast 
quantities of data are processed in order to produce or manipulate video 
images. It is desirable to store and retrieve this data rapidly. Current 
magnetic disk drive technology readily lends itself to this task because 
of the small size, low cost, and availability of standard magnetic disk 
drives manufactured for personal computers and work stations. 
Magnetic disk drives usually include one or more drive platters enclosed 
within a case. The surfaces of the drive platters are formed from a 
magnetic substance capable of storing digital data. Transducer heads 
extend over each platter for the purpose of transferring data to and from 
the platters. Typically, multiple transducers are moved in unison, by a 
single servo drive, over the surfaces of a rotating stack of platters. 
Electronics, often mounted on a printed circuit board on the interior of 
the case, coordinate the transfer of data from the transducer heads to 
digital systems located outside the case, and vice versa. However, 
conventional electronics transfer the data in a serial fashion, i.e., to 
only one transducer head at a time. 
Magnetic disk drives operate best when the drive platters are kept 
extremely clean. Disk drive performance can be hindered when the drive 
platters become contaminated with minute particles of dust. In order to 
keep the drive platters clean, disk drives are assembled in a clean room 
and the covers of the disk drive cases are often hermetically sealed to 
the cases. Once a hermetically sealed case is opened, the drive platters 
can easily become contaminated, which often destroys the disk drive. 
Indeed, manufacturers of disk drives often warn consumers that any 
warranty covering the disk drive will become void if the hermetically 
sealed case is opened. The sensitive nature of drive platters has created 
a frustrating situation for those who perform work on the interior of disk 
drive cases. 
Thus, it would be desirable to have a disk drive that could rapidly store 
and retrieve data for video image processing. For the reasons indicated 
above, it would also be desirable to achieve this goal by modifying 
existing standard disk drives to increase their storage and retrieval 
rates in a way such that work performed on the interior of the disk drive 
case would not contaminate the drive platters. 
SUMMARY OF THE INVENTION 
One aspect of the present invention provides for simultaneously utilizing 
all of the transducer heads in a standard disk drive such that they all 
read or write data to or from the disk drive platters at the same time. 
Another aspect provides a method for converting a standard disk drive from 
serial operation (i.e., only one transducer head reading or writing at a 
time) to parallel operation. 
Another aspect of the present invention is a method and apparatus for 
protecting the disk drive platters from damage and contamination while 
permitting access to electronic circuitry within a disk drive case. 
A better understanding of the features and advantages of the present 
invention will be obtained be reference to the following detailed 
description of the invention and accompanying drawings which set forth an 
illustrative embodiment in which the principles of the invention are 
utilized.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 6 is a schematic representation of a rotating stack of platters 10, 
corresponding transducer heads 12 and transducer lines 18, and serial data 
directing circuitry 14 found in a typical prior art disk drive 16. 
Transducer heads 12 can magnetically store and retrieve electronic data to 
and from both the top and bottom surfaces of the platters 10, with each 
surface having a separate transducer head 12 associated with it. The 
transducer heads 12 are moved in unison by a servo drive (not shown) so 
that they may be selectively positioned radially along the platter 10 
surfaces. 
The transducer heads 12 are also known as read/write heads. In the "write" 
mode, the transducer heads 12 are moved over the surfaces of the rotating 
platters 10 while electronic data is supplied to one of the transducer 
heads 12 via a transducer line 18, and the data is magnetically recorded 
on a surface of one of the platters 10. In the "read" mode, the transducer 
head 12 is positioned over the rotating platter 10 where data was 
previously recorded, and the transducer head 12 senses the magnetic data 
on the platter 10 to electronically transmit the data back along the 
transducer line 18. 
Prior art disk drives 16 include serial directing circuitry 14 for 
directing the electronic data from a signal line 20 to one of the 
transducer lines 18 and vice versa. The directing circuitry 14 may include 
switching circuits, data buffers, and amplifiers for boosting the strength 
of the data signals read from the platters 10. The directing circuitry 14 
interfaces with the servo drive (not shown) and a platter rotational 
synchronization circuit (not shown) to coordinate the radial and angular 
positions on the platters 10 that the data is written to or read from. 
When the prior art disk drive 16 is used in conjunction with equipment such 
as a personal computer, the computer sends and receives data to and from 
the disk drive 16 via the signal line 20. The directing circuitry 14 
coordinates the flow of data between the signal line 20 and one transducer 
line 18 at a time. 
An advantage of the present invention over the prior art is the ability to 
utilize more than one transducer head 12 at a time. As shown in FIG. 7, 
and according to the present invention, the serial directing circuitry 14 
is disabled, bypassed, or altogether removed and a separate signal line 
20' is connected to each transducer line 18. A modified directing means 
(not shown) is connected to the signal lines 20' and allows all of the 
transducer heads 12 to read or write data simultaneously. 
In the preferred embodiment, depicted in FIGS. 1 through 5, the serial to 
parallel modification is performed on a standard magnetic disk drive 16 
having eight platters 10 and fifteen transducer heads 12, such as a 
WREN-6, model no. 94196, manufactured by Seagate Technology, Inc., Scotts 
Valley, Calif. To modify the conventional drive, each pre-amplifier 
integrated circuit (chip) 22 of the conventional drive is removed from 
circuitry 24 located inside hermetically sealed case 26 (typically, there 
are three pre-amplifier chips 22). Each chip 22 is replaced by the end 121 
of a flex-connector 122 (shown in FIG. 1A) that is routed outside of the 
case 26 between the cover gasket (not shown) and the case 26. Each 
flex-connector has eleven conductors (in a preferred embodiment). The 
opposite end 123 of each flex-connector couples the flex-connector to the 
circuitry of video equipment (not shown). The flex-connectors are able to 
conduct signals between the fifteen transducer heads 12 and the new 
parallel directing circuits of the video equipment, thereby bypassing the 
serial directing circuitry 14 of the standard disk drive 16. 
Although the data channels (transducer lines 18) are "broken out" from the 
disk drive 16, other circuitry such as the transducer head servo (radial 
position) control 28 and the spindle servo (platter rotation) control (not 
shown) remain intact and are accessed through the original connector (not 
shown) supplied on the disk drive 16. A spindle servo signal is also 
broken out of the disk drive 16 and supplied to the external data 
directing circuitry to synchronize the transfer of data with platter 10 
rotation. 
In a preferred embodiment, three flex-connectors 122 emerge from the rear 
30 of the disk drive case 26. The disk drive 16 is manufactured with a 
circuit board (not shown) mounted on the rear face 30 of the case. To 
reduce electromagnetic interference to the three flex connectors, this 
circuit board is relocated to one side 32 of the case 26. 
Another aspect of the invention, shown in FIGS. 1 through 5, involves the 
apparatus used to protect the platters 10 from contamination or damage 
when work is being performed on the inside of the disk drive case 26 (for 
example on circuitry 24 within case 26). A hinged cover 34 is provided to 
replace the conventional disk drive cover (not shown) once the 
conventional cover has been removed. The hinged cover 34 shields the 
platters 10 and the inside of the disk drive case 26 except for a cutout 
portion 36 that exposes a portion of the inside of the case 26 to be 
worked on. 
A flange 38 is attached to the edge of the cutout 36 and protrudes 
partially into the disk drive case 26. An elastomeric grommet edging 40 is 
provided along the lower and side edges of the flange 38. The grommet 
edging 40 on the side of the flange 38 forms a seal with the inside wall 
of the disk drive case 26 when the hinged cover 34 is lowered into place. 
The hinged cover 34 is removably and pivotally attached to a stationary 
member 42. The stationary member 42 is attached first to the rear side 30 
of the disk drive case 26 and also has a flange 44 that protrudes 
partially into the disk drive case 26. The flange 44 also has grommet 
edging 40 along its lower and side edges and forms a seal against the side 
of the case 26 and against the grommet edging 40 of the hinged cover 
flange 38. 
The hinged cover 34 and the stationary member 42 act in cooperation to seal 
off and protect the platters 10 and other components inside of the disk 
drive case 26 while providing a well 46 to expose a circuit board, flex 
circuit or other internal circuitry 24 to be worked on. The flange 44 of 
the stationary member 42 serves to support the internal circuitry 24 while 
it is being worked on. This circuitry 24 may continue to be wired into the 
disk drive case 26 with the wires, flex circuits, or other conductors 48 
passing through the seal made between the grommet edging 40 of the 
stationary member 42 and hinged cover 34. 
Two L-shaped tabs 50 are attached to the hinged cover 34 and releasably 
engage a hinge pin 52 which is attached to the stationary member 42. This 
arrangement allows the hinged cover 34 in a vertical position to be 
connected to the stationary member 42 and to be rotated down over the 
opening of the disk drive case 26. 
A vacuum hose 54 is attached to the top of the hinged cover 34 with the 
open end of the hose 54 positioned over the well 46 formed by the two 
flanges 38 and 44. The vacuum provided by the hose 54 removes particles or 
debris generated by work performed on circuitry 24 in the well 46. 
In the preferred embodiment, the apparatus of the invention is assembled as 
follows. In a clean room, preferably on a bench with an exhaust hood, a 
disk drive 16 to be modified or repaired is attached to a conventional 
work stand 56 (shown in FIG. 1). The exterior of the drive 16 is vacuumed 
before the sealed cover (not shown) of the disk drive 16 is removed. The 
disk drive cover and its gasket are then vacuumed as well as the cover 
mounting surface 58, mounting holes 60 and the inside of the disk drive 
case 26. The internal circuitry 24 to be worked on containing chips 22, is 
loosened and partially lifted from the disk drive case 26. The flange 44 
of the stationary member 42 is then placed beneath the internal circuitry 
24 to be worked on as the stationary member 42 is attached to the disk 
drive case 26. 
The stationary member 42 is held firmly in place by two fasteners 62 which 
thread into existing holes 64 in the back of the disk drive case 26. The 
hinged cover 34 is then attached to the stationary member 42 by inserting 
the L-shaped tabs 50 under the hinge pin 52. The hinged cover 34 is then 
pivoted down over the opening of the disk drive case 26 and is held there 
by its own weight and by its hinged connection with the stationary member 
42. 
The grommet edging 40 on the hinged cover 34 comes in contact with the 
conductors 48 of the internal circuitry 24 and with the grommet edging 40 
on the stationary member 42. This isolates the internal circuitry 24 from 
the rest of the inside of the disk drive case 26. The internal circuitry 
24 is supported from below by the flange 44 of the stationary member 42 
and is further held in place by the conductors 48 of the internal 
circuitry 24 that are constrained between the grommet edging 40 of the two 
flanges 38 and 44. Low pressure within vacuum hose 54 removes particles 
from well 46 while the internal circuitry 24 is being worked on. 
Modifications or repairs may now be made to circuitry 24 of disk drive 16 
without the danger of contamination or damage to the platters 10 or other 
internal components. One such modification, as discussed above, is to 
replace pre-amp chips 22 with flex connectors exiting the disk drive case 
26. This results in a modified drive 16' having multiple signal lines 20' 
into the disk drive case 26 enabling the disk drive 16' to read and write 
data to all of its transducer heads 12 in a parallel fashion. 
After work has been completed on circuitry 24, the reverse of the above 
steps is performed. The hinged cover 34 is removed by rotating it upward 
into a vertical position and disengaging it from the hinge pin 52 of the 
stationary member 42. The stationary member 42 is then unfastened from the 
disk drive case 26. The internal circuitry 24 that was being worked on is 
reattached to the inside of the disk drive case 26 and the conventional 
disk drive cover (not shown) is replaced. Thorough vacuuming during 
reassembly ensures that the platters 10 will remain clean. 
It should be understood that various alternatives to the embodiments of the 
invention described herein may be employed in practicing the invention. It 
is intended that the following claims define the scope of the invention 
and that structures and methods within the scope of these claims and their 
equivalents be covered thereby.