GB2354093A - Plural pointing devices - Google Patents

Abstract

A system enables the use of multiple pointing devices which generate data in different protocols by determining which is the largest of the protocols used and converting data packets from the other pointing devices into this protocol by adding bytes as required. The operating system 58 running a program 60 requires a single size input which is provided by the keyboard and auxiliary device controller (KBC) 50 which receives signals from pointing devices 52 and 54 which can have different protocols. The KBC can send a command to each pointing device to indicate what size of data packet it will produce and then analyse these signals to select the maximum data packet size.

Description

2354093 SYSTEM AND METHOD FOR SYNCHRONIZATION OF POINTING DEVICES WITH

DIFFERENT DATA PACKET SIZES

BACKGRIWORM OF 7-M-LWIEMION 1. Field of the

The invention relates generally to controllers for computer pobv devices and specffically to controllers for use with pointing dences generating dam packm of di&zmt sizes.

2. pmw "d 91.fte Rdated Art Modem notebook or Isptop personal compW= 4pcally ptovide an W=d built-in pointing devIce for movem= of ft display cursor, as weU as a connector for connecemg au Pohft device ft confrol of the display cursor. Fig. I show a block diagm of the major hadware components of a typical notebook computer lo vft internal ad Wanal pointing devices.

The notebook computer 10 Wades a keyboard and auxiliary device comoller, 00C) 12 connocted to a keyboard 14. brernd pohft device 16, and en=al poiting device 1g. Mm Wboard 14 is; connected to the KBC 12 via a keyboard intertace 20. The internal point1mg device 16 is connected to the KBC 12 via a fnt autBary interfm 22.]For notebook compWm, the interad pointing device 16 is typically a tourA pad, Wickball, or pointing stick built into the computer to control Movement of the display cursor. The egemal pointing device 19 is counwted to the XBC 12 via a second anxViary kwace 24. JU ammal pointigg device 16 is typically a mouse or trackball comected to in exurnal connector of the computer. to provide an alternative means fbr control of the display cursor.

- The KBC 12 is connected io a qst= bus 26 which is connectcd to cpU 28. The]KBC 12 sends and receives data and control signals to and from the system, bus 26, and receives data from the keyboard 14, internal pointing device 16, and eidernal poinft device 18.

The standard EBM PW mouse genaates data packets contaming three bytes of datq., as shown in Fig. 2. These three bytes include one status byte contaiiiing data relating to the pohttwg device buttons and other soft data (40), one data byte for datayejamg to movemnt of the cursor in the horizontal or X direction (42), aW one data byte for data rejaen to movement of the cursor. in the vertical or Y direction (44). This ccmveatioW dwa packet thus provides three bytes to describe cursor movemW in a two-dimensiond (i.e. X-Y) pkw.

The new Mcrosoft IntelliMouse (and compatible poing devices made by oaw maindherurea) includes a wheel control fbr scrolling the dbylay screen (Ws can be considered control of the cursor movemw in the Z direction). To --waodate, this additiozW cursor control fuwtion, the can opwo in an extended mode in whkh it generates dau packets contairdqg folur bytes, as shown In Fig. 3. Thm of the bytes contain the same dam as a standard mouse, ie. out status byte (40) and two data bytes for cxusor movement in the X and Y directions (42 and 44). and e A=& byte contains dam relating to scrolling of the display (46). TWs type of mouse will be refined to as an extended mode Otating device.

is The notebook computer's operating system includes a software device driver (e.g. a mouse driver) wbich processes data received fi-om die uttemal and mamma pokmg devices m order to genaraft sismal to contral dw movement of the display cursor. IU device driver typically switches to an extended mode In order to "t the four-byte daft packM gwerated by an extended mode pointing device. However, when the mouse driver wables this extended mode, it can no longer accept standard tbre,-.byta data packets. Furthermore, in order to switch out of this extended mode. the operating system must typically be restarted. one existing solution to this problem is to automaticaUy disable the internal pointing device when an external pointing device is connected and the system driver switches the system into extended mode for accepting fbur-byft dMa packets. However, this approach makes it impossible to operate both an internal and external pointing device at the sa time, and dn user cannot use both pointing devices simultaneously.

RaMAARY OF TO DOMEMON ne present invention Is directed to overcoming or at least reducing the effma of tjje problem set hrth above. The present invention embles the use of one or mom polating devices with a computer, whom the pointing devices generate data pacimb of differew gim. ne maxinsm size of the dwa packets generated by die pointing devices is detmmgneC ad any data packeu received from Ihe pointing devices which am maner tban the mLcrmm= size bave additional bytes added to increase the size of ft data packet to the maximum si=.

Thus, hL accordance with one aspect of the invention, a mithod, for openting a iu conjunctim with one or more pointing devices is provwed indudiuS dle SVB of ining a mwdms= Aze of The data packets g=eraW by the pointing dcvkA%, rweiving a &a data pactet from a ftt pointing device, det=Aft it the fim data packet bag a size smaller dm the maximum she, and inCreasing the size of the first data packet so that the fim data packet bas a size equal to the maxt=rm size.

In accordance wM another aspect of the invention a computer system is provided out or more pointing devices which generate daft packets and a controller connected to the pointing devices for receiving the data pa6kets. The. controller det=ainea the size of the dala packets and adds one or more bytes to each data packet received from the pointing devim which is smeller dw the maximm size. 11m controller may determine the maximum size of the data packets by sending a command to each of the pointing devices fbr causing each of the pohWng devices to respond with a device identifler indica&g the sin of data packet generated by dhe respective pointiqg device. The controller receives the device idenfifiers from die pointing devices and analyzes the device identifiexs to detwmine the maximam size of the data packets generated by the pointing devices.

Asa rook of use of the invention, -11; operation of multiple pointing devices is possiWe even wIten an exMded mode poinft device or other pointing device with a non smdud data packet size is used. Thus, anoftbook co=pnw user may eqjoy the convaince of using both bmnal and external pohming devices V= OF M DRAMMM IU fbregoing advantages and features of the. Invendon will become apparent upcm rdbreace to the Wowing dftuW description and Ow - -, Ouying drawings, of Which:

Fig. I is a block diagram of The bardware for a computer with internal and exterag pointing devices; is Fig. 2 is a diagram. showing dats. packets gmwskd by a Mudard pobting device-, Fig. 3 is a diagram showing data paets generaW by an extended mode pohitiag devk.

Fig.-4 is a block diagram of dw software: and ftmware components of a computer with hnrnal and external pointing devices; Fig. 5 is a ftow chart showing a program to permit the use of both internal jMd extmg pointing devices, including an extended mode poindng device; Fig. 6 is a flow chart showing dLe processing of a "Read M" command received from a device driver; and Fig. 7 ad 8 are flow charts showing the procenig of a data. byte received from a pointing device.

While the invention is susceptible to various and alternative fbrms, specific embodimeM havc been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not limited to dw particular fbrins disclosed. Rater, the invention covers all equivalents, and alternatives fellin within the spirit and scope of the invention as deffned in dic appended rjahnn.

DMAR,F_D DESCREMON OF V_g= EMBODBMff S one specific embodiment of the invention is described below with reference to Fip. 4 tD S. IU angwdin2mg makes use of the &ct that: the KBC in a notebook computer provides a COMM= -- Mn, ebannel fbr all commands and data sent between the device driver and both Internal and eMernal pointing devices. In this embodiment, die KBC controller - -- ----- ft 8111W ID coinmaW = frcm the device driver to ft poindn,g devices at startup and mports back to the device driver the device M of ft pointing device with the modmm size of dam padiet All data packets ftm pobting devices with fewer bytes than the maxinnni are padded by the ICBC with additional bytes so diat the overall size of the data pacjwt ftm each poindug device is ft same and is equal to the MaXWHIM sim As a resuli tte device driver always receives data packets of the same (maximum) size, allowing normal operatiou with poindng devices wM difrerent data packet dimezisims.

Turning now to the drawings and referring initially in. Fig. 4, a block diagram is shown of the softviare and firmware components for a notebook computer winh intmnal and externai poinft devices. The KBC 12, intemal pointing device 16, and external poinftg device 18 shown in Fig. I!Wuda, respectively, KBC firmware 50, intmal poiitWg device firraware 52, and extemal pointing device firmware 54. The internal and external pointing device firmware 52 and 54 providn the pointing devices with the ability to receive commands from the compuUr, and send data back to the computer corresponding to the movetne= of the pointing device and pofiWng device buftons. A device driver 56 is typically included as part of the computer's operating system software 58. Device driver 56 opaws as &e haerface betweem the operating system softwam 58 and the pointing devices 16 and 18.

no IKIIC fimware so COMMUM with the ntarad potntlqg device firrawam 521 cmud pointing device firmwarc 54, and device driver 56. Ue device Mver 56 typical1y unicates with an gplication program 60 which controls the movenwat of the cursor on the display. Thus, dam from die pointing devices and control conunands from the device driver may be cKchanged by inftraction of the KBC ftwwarc 50. Intenal poititing device firmware 52, cxftrnat poinde device firmwan 54. and device driver 56. Because all commands and data exdMmgod ba=en the device driver 56 and pohitmg devu= are channeled through dic KBC, the additional logic reqWred to synchronize the data padreft from standard pointing devices and extended mode pohiftg devices can be conveniently included in the NBC firarware 50.

r-Ig.-5- shows a flowchart for a program Omt may be included in the KBC firmware 50 oD permit use of both internal and exftnal pointing devices, where the exmmal pointing device may be an extended mode pohdng device. Initially, the program waits to receive either a command fimin the device driver 56 or data ftom one of the pointing devices 52 or 54 (step 100). Once either a command or dam byte is received, the program determines if a "Read IID" conimand was received from the device driver 56 (step 102). If a "Read XID" command was received. the command is processed as shown in Fig. 6 and described below (step 104) and the program subseTmfly returns to sup 100 to await receipt of anodier command or daft. If a data byte was received (and a "Read ID" command was not zeceived) (step 106), aLe data byte is processed as shown in Fig. 7 and described below (step 108), and dw program subsequendy rewns to stop 100 to await receipt of ano&cr command or data. if a command odw dm a "Read 13D" command was received, or data other din d9a from ft poinfM devices wo received (e.g. data ftom the keyboard), dw command or dam is processed in tILe conventional manner (step 110) and the program remrns to step 100 to await receipt of ano&er commud or dam.

Fig. 6 Mustraft ft procenin of a "Read IDn command received from device driver 56. A -Read 13D- mmand Is typicaRy generated by the device driver 56 when Ow opernift r1dem 58 Is awned to determine the types of poinftg devices connected to dw computer.

When a -Rmd MO cammand is received from the device driver:56 (stop 120). dw command is swt to Me WavAl pohft device, and ft internal pointing device firmware 52 generates a device M in response to dw command. Mw device ED for a standard pointing device is OxOO and for an Wended mode pointiqg device it is OxO3. 11is device ED is sent back to ft KBC firwwwo 50 and the device ID Is saved (stop 122) for use by the program at a later stp. nc -Read M- wmmand is thm sent to ft afternal poinft device and the device M rewived in response from the uternal pointing device firmware 54 is saved (stop 124).

The program next checim to see if a device ID for an exMded device (i.e. OxOS) was received from any of te pointing devices (stop 126). An exended, device M will be generated by a pointing device that produces four-byte dam packets (such as an extended mode pointing device), requiring the device driver to operate in extended mode. If no extended device M was received firom the pointing devicu, the system ID is set to 0x00 to indicate that all of ift Poiziting devices are standard type and that no extended mode poinftg devices an connected (step 128).

If an extended device M was received from the pointing devices, the systm]]D is set to M3 to indicate that at least am awnded made pointing device is connected and to enble operation In extended moft (swp 130). The r1stem ID detemined ftve Is ttwn sent back to the device driver 56 (step 132) and the byte counters (described below) for all pointing devim am rem to thek initial value (step 134).

Figs. 7 and 8 Mustroft the processing of a data byte received tram a pointing device.

As shown in Fig. 7. when a data byte is received from ane of the pointing devicu (" 140), fle prograza checks to see if die byte Is the fm byte of a data packet (step 142) by -Was if the byte counteris at its initial vWne. Mw fiat byte of the dWa packet contaim stato data ftw1hepointing device (as shovrnjnj:gs. 2 and 3). CMventionalpoinflngdevi= include one or more buttons for selecting disphy iom or perfonning adw operations. The statu daft for then buttons (Le. which baftm the um hu pressed) is included in the status byte of the data packet generated by the poindag device.

If the dam byte received is the first byte. de statas of the pointing dMcc, buftm is saved (step 144). The first; byte Is identifted by examiniqg the byte counter. TbLe byte counter is a counter that is incremented as each byte is processed, and reset to an irdtial value Whert a compleW dam packet has been processed. 1lie byte counter will be at Its initial value if the byte is the first byte. The program than perfbrms a logical OR operation on the pointing device button status fbr all of the pointing devices, to determine if any of the pointing device buttons have been pressed by the user (step 146). The resWt of the OR operafion is sent to the device driver 56 (swp 148) and the byte counter is incremented (step 150)- At this point, ft processing of the data byte is complete, and the prograin. resumes waiting for a command or dam at step 100 shown in Fig. 5.

If the data byte received is not the ftM byte, the byte counter is examined to M if the byte is the last byte (step 152). A byte counter vake of three will Indicate the Iast byft of the packet if the poindmg device that Setit the dM byte generated a standard device M (i.e. OxW), and a byte counter value of fbur will hidicate the last byte of the packet if the pointing device that sent the data, byte generated an extended device M (i.e. 043). If the data byte received to w the first byte or IM byte of ft dam padog, ft data byte is sent to the device driver 56 (s" 154), the byte coun is h=emented (step 156). and the processing of the data byte Is uwmwau resumes waiting for a command or daft at step 100 shown in Fig. S.

If the data byte received is the last byte of the data packet the byte is processed as shown in Mg. 8. in c==t designs. for a standard pointing device with device ID of OxOO, the last byte will be the &W byte of the data pad=, as indicated by the count accmmulaftd by the " counter, as deambed above. Fm an extended mode pointing device with device IDD of OxO3. the last byte will be the fourth byte of the data pacimt, as hWk=ed by the byte counter.

Note that tho present invendon is not limited to dwo particWar devicc Ids. but may be ejawded w include any device IDs used to indicate the size of the data packet generated by a pointing device.

If the device ID generated by the pointing device that sent the data byte is the same as ft system. ID cakidated by the program (shown in steps M and 130 of Fig. 6), this indicates that either: (1) no extended mode jointing device is connected (i.e. a ftee-byte data packet wiII be expected) and the pointing device sending the data is a standard pointing device, or (2) an extended mode pointing device is connected (Le. a four-byte data packet will- be expected) and the pointing device sending the dam is an extended mode pointing device. In aid= situation, the program need not make any adjustmat to the data packet size received "M the pointing device bemuse it mawAes the data packet size Mected by the device driver 56.

Thus, ramming to Fig. B. if the device ID equah the system ED (Step 160), ft data byte is se= to the device driver 56 (step 162), dw byte counter is reset to its inidal value (step 164), and the processing of the data byte is complete. The program resumes waiting for a comms' or dam at stop 100 dwwn in Fig. 5.

If the device ED is dUftent from the sysmm IID, this incli dMt the pointing dcvice sending the data Is a sftnd2 d pointing devim in a system that includes an enended mode pointing dcvice. nus, the data packet received from the standard pointing devica wM omly include ftee bytes and must be padded in order to prodwz a four-byte data packet expected by the device driver 56. Ihe data byte received is seat to die device driver 56 (step 166). The prograin then waits fbr a period of tinav to emnlato the trawmission aud pro de4y that would occur if the program waited for anolher byte of data from the pointing device (stop 168) - The program dxn generates a data byte conWning zeros (or any otber suitable paddiW and sezds the byte to the device ddm 56 (step 170). Ws additional byte ext=& the dam packet froul the pointing device so that a four-byte data packet will be received by the device driver 56. The byte counter is then rem to its initial value (step 172), and theprocessing of Me data byte is completa. The program resumes waiting for a command or data at step 100 sbown in Fig. 5.

Thus, one embodiment of the invention has been described providing a mean to enable the use of multiple pointing devices Which geneWe data packets of different sizes. Ile described above with reference to Figs. 4 to 8 illusbues one means for enabling the use Of a SMUftd POiDtW device (genMWS WM-bYte dZta Packets) and an CXtMded made pointing device (ganmWAug four-byte data packets). However, &e descriBbed progrwn could be readily modified using conventional tedmiqaes well known to those of skill, in the art to t.he VstIrg 1 Of different computer systems.

For example, the program could be modified fbr operation wM muitiple Pointing devices where the data packet sizes vary by mom than one byte, by mkbog multlc bytes to the smaller data packets to match the size of the largat data packet. Sitailarly, tbe pp.

could be modified to allow for ftw or more difftent sizes of dan, packets, by adding the number of bytes needed to make cach data padkiet cqiW to the largest dM pacleft generated by any of ft pobsting devices. MW program also could be modified for operation with any munber of mlernal Pointing devices and ww m=bcr of external pobiting devices. For example, the progm could be modified to op=te with a notabook: computer wM a unch pad and a poinflng stick. and one or more external pointing devices as well.

im addition. the program could be modified to use a different ftchniqae for dewra"" the size of dau packet gencrated by eWA pointing device. For =ample, the size of the data packet could be coded into ft statas byte of each data packet, and the program could use this dam to detemine ft m, er of dam bytes expectect from the pointing device and the maximum size of dam packet expected from any of dw pointing devices.

F ft embodhaW of the invention descnlW above is entirely in software residing in the KBC. However, adker tecl%niques could be employed to implement the logic. For example, thefimcdons of the program illumated in Fip. 5 tD 8 cowd be implemented using softwam included in the device driver or included as a sepamte component of die compuW's operating system. Akernatively, the functions of the program could be modffied for implementation using Wdware such as a prograrnm le logic array or sbnilar device.

Many wher modifications and varMons, may be made to the tedimiques and structures 5 described and illustrated without departing from the spirit and scope of do invention. Accordingly, ft should be understood dw the methods described harein me Illustrative only and are not limiting upon the scope of the invention.

Claims (10)

1. V4M is claimed isI. A xnethod for operating a computer in coujuncdon widi

   one or More pointing devices which generate data packcu, the method comprising ffie steps of:

   W Miming a inaidmilm sin of said data packew generated by said one or more pointing devices; receiving a first dam pa&et tom a AM pointing device, said fust pohift device being one of said one or more pointing devices;. I. U said fim data Packet his a size smaHer than said ma3timum size; and hmenins said size of said fhu dM Packet so that said SM data pacimt has a du equaI to said maidnim sin.
2. 2. IU nothod. of claim 1. wherein said stop of dawnnining a numtmum size of said dam podkeft coupftw:

   sending a comnumd to each of said pointing devices fbr causing each of said pojnting devices to respond with a sigul indicaft a size of data packet genez-ated by the respective Pointing device; receiving said signals from said pobtWg devica; and anaryziag said dpals to determine said maxinum size of said 4ata packets generated by said pointing devices.
3. 3. The mediod of claim 2. wherein said step of determining if said first data packet has a size smaUer dw said roaximum size comprises:

   receiving a fint siguaI from said first pointing device; identifying a second signal corresponding to said maxim= sizk of sad data packets; and comparing said fht signal to said second siVW, wherein if said first siglIal isnot equal to said second signal then said fMt data packet. has a size smaller than, said mmxImum size.
4. 4. The mcdkod of claim. 3, wherein said step of increasinS said size of said first data packet comprises:

   generAdPg One Or more additiond data byta if sdd fM sjgW is not eqUI to aid sacmd, signal; and addin add one or more additional data bytes to said fust data pwket.
5. S. -Me medwd of claim 1. Wherein said compuuz ft opomted in conjunction, with two or =re pofiWag devices. including Ow or More btand pokWag devim and one or more extezzal pohlft devices.
6. 6. A comFuter system comprbstg:

   one iDr more pohdng devices, each poW&g device for genwiti[Ig a d= paclog; a controller conmted to said poiaing devices for receiving said data, p=krls, determinin a ma)dmwn size of said data packets, and adding one or more bytes to each data packet received from said pointb2S devices whieb is smaller dum said maximum size.
7. 7. The computer system of claim 6, wherein said controller damnim said maximum size of said dam packets by sending a commumd to each of said pointing devices fbr causing each of said pohiting devices to respond with a signal indicating a size of data packet generated by the respective pointing device, receiving said signals from said pokiling devices; and analyzing said signals to determine said maxhum size of said data pad= generated by sak pointing devices.
8. 8. Mm computer system of claim 6. wherein said poinUng devices include one or more 1,4911, pointing devices and one or more cxternal pointing devices.
9. 9. A couqmta system comprising:

   a first pointing device for generating a firstsignal and a first dam pac3m; a second pointing device for generating a second signal and a second data packeta controller connected to said first and second Pobiting devices for receiving d first signal and &,st dam packet and said second WSW and sw4w data packet, analyzing said signals to determine mid maximum size of said daft packets generated by said pointing devices, sad adding one or more bytes to each data packet received fimmsald pointing dmces which is smaller than said size.
10. 10. The computer system of claim 9 whercin, said first pointing device is an internal pointing device and said second pointing device is an externW pointing device.

    -16 it. A controller for use with a computer in conjuucuon with one or more poinfin devices which X-e-s- w-rate data. packets, the controller comprising:

    means for dftmdning a maximum size of said data packets generated by said one or move pohft devices; mem for Mehfing a fiW data packet from a first pointing device, saId &a poWftg device bejAg one of said one or more pointigg dMces; means fbr determining if said first data packet bas a size smaller than s9d mwdmum size; and nwan for increag said size of said lint dam packet so that said first data packa has a size equal to aid maxbnum size.