BBS in a Box 5

home *** CD-ROM | disk | FTP | other *** search

/ BBS in a Box 5 / BBS in a Box -Volume V (BBS in a Box) (April 1992).iso / Files / Apple / Apple II TNs(Text).cpt / Apple II TNs(Text) / IIGS / TN.IIGS.035 / TN.IIGS.035

Wrap

Text File | 1989-11-15 | 35.5 KB | 932 lines | [TEXT/pdos]

Apple II Technical Notes _____________________________________________________________________________ Developer Technical Support Apple IIGS #35: Printer Driver Specifications Revised by: Matt Deatherage & Suki Lee September 1989 Written by: Dan Hitchens May 1988 This Technical Note describes the routines and internal structures needed to design a printer driver for the Apple IIGS system, and you should reference it in conjunction with the Apple IIGS Toolbox Reference manuals. An overview and associated parameters for each of the printer driver routines are in the Print Manager chapter, and you should reference these for a complete picture. Changed since March 1989: Added System Software 5.0 calls and the new driver structure. _____________________________________________________________________________ Printing Modes There are two printing modes: immediate and deferred. o Immediate mode (also known as draft mode), uses the technique of printing immediately. As you make QuickDraw II calls, you immediately generate commands which cause printing to occur. This mode is the fastest form of printing, but it can only print characters in the printer's native mode. (However, the LaserWriter translates the QuickDraw II calls into PostScript calls which can produce high-quality pixelmap images.) o Deferred mode (sometimes referred to as spooling), uses the technique of capturing the QuickDraw II calls for each page in a picture file and plays them back at a later time. To produce high-quality pixelmap images, you must use deferred mode because of the memory constraint of not being able to draw a complete page in memory at one time. Due to this limitation, we draw a band (a partial page) at a time. We create a GrafPort which corresponds to the band and play the picture file back, thus causing the saved commands to draw only the images which fall within the band. Once the pixel image for the band is generated, we can send it to the printer one pixel at a time. File Structure The user can install new printer drivers into the system by copying a printer driver file into a subdirectory called DRIVERS within the SYSTEM subdirectory. The printer driver file must be of type $BB and have an auxiliary type of $0001. Print Driver Calls A printer driver must support the following calls: PrDefault $0913 Sets print record to default PrValidate $0A13 Validates print record PrStlDialog $0B13 Performs a style dialog PrJobDialog $0C13 Performs a job dialog PrPixelMap $0D13 Prints a pixelmap PrOpenDoc $0E13 Opens the document PrCloseDoc $0F13 Closes the document PrOpenPage $1013 Opens a page PrClosePage $1113 Closes a page PrPicFile $1213 Prints a picture file --RESERVED-- $1313 PrError $1413 Gets the error value PrSetError $1513 Sets the error value GetDeviceName $1713 Gets device's name PrDriverVer $2313 Gets installed driver version Printer drivers may support the following calls if they use the new driver structure outlined below: PrGetPrinterSpecs $1813 Returns printer type and characteristics PrGetPageOrientation $3813 Returns page orientation Print Driver Entry o For older drivers, entry is at the first byte (no offset). For newer (Print Manager 3.0 and later) drivers, the first word is $0000, indicating a new style driver. The next word is a count of how many calls this driver supports. All drivers must support the minimum call set. Additional calls must be supported in the sequence listed (for example, if a driver supports PrGetPageOrientation, it must also support PrGetPrinterSpecs). o The content of the x register is calculated beforehand for use as an index to the correct routine (see the example and note the specific ordering of the routines). o There are two long return addresses (six bytes) that have been pushed onto the stack. (You must take these addresses into account to access the parameters and to return correctly.) Example StartOfDriver START dc i2 '0' ; new style driver dc i2 '16' jmp (PrDriverList,x) PrDriverList dc a4'PrDefault' dc a4'PrValidate' dc a4'PrStlDialog' dc a4'PrJobDialog' dc a4'PrPixelMap' dc a4'PrOpenDoc' dc a4'PrCloseDoc' dc a4'PrOpenPage' dc a4'PrClosePage' dc a4'PrPicFile' dc a4'InvalidRoutine' dc a4'PrError' dc a4'PrSetError' dc a4'GetDeviceName' dc a4'PrDriverVer' dc a4'PrGetPrinterSpecs' dc a4'PrGetPageOrientation' Print Driver Exit You should adjust the stack to use RTL instructions followed by any return parameters with the two long return addresses. To accomplish this, you will need to do the following: o Eliminate any parameters from the stack which have been passed. o Move the long return addresses so that they are before the space for the returned parameters (if any). Example Figure 1 diagrams the stack just before leaving the print driver: | Previous Contents +--------------------- | Results (if any) +--------------------- | RTL2 (3 bytes) +--------------------- | RTL1 (3 bytes) +--------------------- <--- Stack Pointer Figure 1-Stack Prior to Exiting the Print Driver You should do an RTL with the contents of the flags and registers set appropriately. (See the Return from Call section of the "Using The Apple Tools" chapter of the Apple IIGS Toolbox Reference.) Print Record Structure Since application programs often need to fiddle with parts of the print record (i.e., the values in the style subrecord), we have defined ways for applications to interpret the print record, and specifically the style subrecord. iDev, the first word of the printer information subrecord, has two defined values for third-party printer drivers. A value of $8001 indicates a dot- matrix printer while a value of $8003 indicates a laser printer. A value of $8001 indicates that fields of the style subrecord should be interpreted as they are by the ImageWriter driver, as documented in the Apple IIGS Toolbox Reference. The first seven bits (0-6) of wDev are defined as for the ImageWriter driver. Bits 7-11 are reserved for Apple's use and must be set to zero. Bits 12-15 may be used by third-party printer drivers as necessary; these bits will be set to zero in Apple's drivers. A value of $8003 indicates that fields of the style subrecord should be interpreted as they are by the LaserWriter driver. The first four bits (0-3) of wDev are defined as for the LaserWriter driver. Bits 4-11 are reserved for Apple's use and must be set to zero. Bits 12-15 may be used by third-party printer drivers as necessary; these bits will be set to zero in Apple's drivers. If an application wishes to take advantages of specific features of a third- party printer driver, it has to know that it is dealing with that driver. Since all drivers will look pretty much alike, the Print Manager allows you to ask for the name of the currently selected printer driver. An application may make the Print Manager call PMGetPrinterName, which is documented in this Note. The Print Manager will return the name of the currently selected printer in a Pascal (length byte) string. The name returned is the name of the file from which the driver was loaded. If you intend to use this method to identify a driver, you must inform users not to rename the Printer Driver file on the boot disk. The PMGetPrinterName call is as follows: Note: This is a Print Manager call, not a Printer Driver call. It is the only Print Manager call documented in this Note. Printer Drivers do not include this call. PMGetPrinterName ($2813) Description: Returns a Pascal string with the file name of the currently selected printer driver. Passed: Longspace LONG Space for result Returned: NamePointer LONG Pointer to a Pascal string of driver filename Print Driver Calls PrDefault ($0913) Description: Fills the fields of the specified print record with default values for the printer. Passed: PrintRecordHandle LONG Handle to the print record Returned: None Performs the following: o Validates that PrintRecordHandle is a handle and does nothing if not. o Determines the default values for the print record either through tables or calculations. The default values should take into account such things as paper size and orientation, print mode, printer type, etc. o Copies the default values to the print record specified by the PrintRecordHandle parameter. PrValidate ($0A13) Description: Checks the print record to see that it is valid for the currently installed printer driver. Passed: PrintRecordHandle LONG Handle to the print record Returned: ChangeFlag WORD Boolean; TRUE if the record is adjusted Performs the following: o Checks to see if the print record is from this particular driver. o If the print record is not from this driver, it uses the default values for this driver. o If the print record is from this driver, it makes any changes that might be needed (i.e., style, paper size, etc.). PrStlDialog ($0B13) Description: Performs a style dialog with the user. Passed: PrintRecordHandle LONG Handle to the print record Returned: ConfirmFlag WORD Boolean; TRUE if the dialog is confirmed Performs the following: o Conducts a style dialog with the user to determine the page dimensions and other information needed for page setup (the initial settings of the dialog are derived from the print record). o If the user confirms the dialog, the information from the dialog is saved in the specified print record, PrValidate is called, and the routine returns TRUE. o If the user cancels the dialog, the print record is left unchanged, and the routine returns FALSE. Note: The following are items typically found in printer style dialogs: o Paper Size (US Letter, US Legal, A4 Letter, B5 Letter, International Fanfold) o Printing Orientation (Landscape, Portrait) o Vertical Sizing (Normal, Intermediate, Condensed) o Special Effects: Font Effects (Font Substitution, Smoothing) Reduction or Enlargement Gaps or No Gaps between pages Every printer style dialog should have an OK button (default) and a Cancel button. PrJobDialog ($0C13) Description: Performs a job dialog with the user. Passed: PrintRecordHandle LONG Handle to the print record Returned: ConfirmFlag WORD Boolean; True if the dialog is confirmed Performs the following: o Conducts a job dialog with the user to determine the print quality, range of pages to print, and other specifications. The initial settings are derived from the previous PrJobDialog call (or initial default values) except the page range which is set to ALL, and the number of copies which is set to ONE. o If the user confirms the dialog, PrValidate is called, the print record is updated, and the routine returns TRUE. o If the user cancels the dialog, the print record is left unchanged, and the routine returns FALSE. Note: The following are items typically found in printer job dialogs: o Print Quality (Best, Faster, Draft, etc.) o Color option o Pages (All, Range) o Copies o Paper Source (paper cassette, manual feed) Every printer job dialog should have an OK button (default) and a Cancel button. PrPixelMap ($0D13) Description: Prints all or part of the specified pixelmap. Passed: srcLocPtr LONG Pointer to the source LocInfo which contains the pointer to the pixelmap. srcRectPtr LONG Pointer to the rectangle which encloses the pixelmap to be printed. colorFlag WORD Boolean; FALSE if black and white, TRUE if color. Returned: None Performs the following: o Calls DevIsItSafe (port driver call) to verify that the port it functioning and it is safe to proceed. If it is not functioning, set the internal error code to $1302 (Port Not On) and return with an error status. o Saves the current port. o Turns on the watch cursor to signal the user that it will take some time. o Clears the internal error code (default, if no errors occur). o Gets a new handle for a print record and set it to the defaults by calling PrDefault. o If colorFlag is set, sets bit 5 of wdev in prStl of the print record. o Do any initialization that might be needed by the driver. o Determine the intersection of the two rectangles (rectangle pointed to by srcRectPtr and the pixelmap's boundary rectangle from srcLocPtr) and if there is no intersection, then nothing is to be printed. o Print the pixel image which is within the intersection of the two rectangles. o Cause a page eject to occur on the printer. o Do any clean up that is needed. o Turn off the watch cursor by calling InitCursor. o Restore the port by calling SetPort. PrOpenDoc ($0E13) Description: This routine initializes the things needed to open a document. In deferred mode, it establishes a GrafPort and makes it the current port for printing. Passed: PrintRecordHandle LONG Handle to the print record PrinterPortPtr LONG Pointer to the GrafPort, if desired, zero to allocate a new GrafPort Returned: PrinterPortPtrRet LONG Pointer to the GrafPort if the PrinterPortPtr was zero Performs the following: o Calls DevIsItSafe (port driver call) to verify that the port is functioning and it is safe to proceed. o Turns on the watch cursor to signal the user that it will take some time. o Validates the print record passed by calling PrValidate. o Clears the internal error code (default, if nothing happens). o Puts up a dialog indicating that printing is occurring (or preparing to print). o If the user needs a GrafPort, create one and internally note that one was created (PrCloseDoc will need to know that one was created here). o Initializes parameters (i.e., page number, document number, etc.). o If deferred mode, create an initial page list (an array of handles to pictures) for 20 pages (arbitrary number to start). o Do other initialization that might be needed to start a print job. Possible errors: $1302 Indicates Port Not On PrCloseDoc ($0F13) Description: Closes the GrafPort being used for printing. For immediate mode, this routine ends the printing job. For deferred mode, this routine ends the process allowing the job to be printed. Passed: PrintGrafPortPtr LONG Pointer to the GrafPort used for printing Returned: None Performs the following: o Checks that the last print driver call did not cause a Port Not On error. If the error occurred, do nothing and return. o Call ClosePort (port driver call) to close the port. o If the driver allocated a GrafPort in PrOpenDoc, dispose of it. o If in immediate mode, do what is needed to shut things down. o Takes down the information dialog box from PrOpenDoc. PrOpenPage ($1013) Description: Begins a new page only if the page falls within the page range specified in the job subrecord. Passed: PrintGrafPortPtr LONG Pointer to the GrafPort used for printing PageFramePtr LONG Pointer to the scaling parameter, zero for none. Returned: None Performs the following: o Looks at the driver's internal error value, and if an error has occurred, it returns without doing anything. o Increments the page number. o Calls SetPort to make the specified port the current port. o Initializes the port and zeroes the boundary rectangle so no actual drawing will occur. o If immediate mode, then do the following: If this page is to be printed, install immediate mode procedures by doing the following: o Create a procedure table (get the standard procedures. from SetStdProcs). o Put pointers to your procedures into the table and call the QuickDraw II routine SetGrafProcs. This will cause QuickDraw II calls to print instead of writing to the GrafPort. o If deferred mode, then do the following: o If the current page is out of the page range, then return without doing anything further. o If the user passes his own PageFramePtr , then get it. o Open a picture by calling OpenPicture and adding its handle to the page list array described in PrOpenDoc. o Set the ClipRgn and VisRgn to the sizing framing rectangle specified by PageFramePtr , or if none was specified, to the default of rPage. PrClosePage ($1113) Description: This signals the end of a page. Passed: PrintGrafPortPtr LONG Pointer to the GrafPort used for printing Returned: None Performs the following: o Looks at the driver's internal error value and if a Port Not On error has occurred, it returns without doing anything. o If immediate mode, do the following: o If the current page is within the range of pages to be printed, then cause a form feed (unless no gap was specified). o If deferred mode, do the following: o If there was no picture generated, then do nothing and just return. o Call SetPort to make the specified port the current port. o Do a ClosePicture to close the picture. PrPicFile ($1213) Description: Prints a picture file generated in deferred mode. Passed: PrintRecordHandle LONG Handle to the print record PrintGrafPortPtr LONG Pointer to the GrafPort used for printing StatusRecPtr LONG Pointer to the printer status record Returned: None Performs the following: o Looks at the driver's internal error value and if a Port Not On error has occurred, it returns without doing anything. o If immediate mode, return without doing anything. o If deferred mode, then do the following: o If the error code is not zero (errors) then dispose of everything. o Put up an information dialog indicating that printing is occurring. o If PrintGrafPortPtr is NIL, create one and make a note of it. o Call OpenPort to make the GrafPort the current port. o If StatusRecPtr is NIL, use an internal one. o Initialize the status record and the number of copies counter. o If the idle proc in the print record is NIL, point to an internal one. o Do The Following For Each Copy: o Calculate the number of bands it will take to print one page and initialize the page counter. o Do The Following For Each Page: o Call the idle procedure routine and initialize the band counter. o Get the handle to the picture associated with the current page. o Set the dirty flag in the status record to FALSE. o If manual paper feed, put up a dialog and wait for a response. o Do The Following For Each Band: o Call the idle procedure. o Calculate the band rectangle and update icurband with the current band number. o Call the idle proc again. o Set the imaging flag in the status record to TRUE. o Call InitPort to reinitialize the port. o Adjust fields in the port to cause drawing into the band buffer. o Adjust fields in the location information field of the status record and calculate the sizing rectangle. o Calculate the boundary rectangle for the band and set the port rectangle to it. o Set the ClipRgn and the VisRgn to the sizing rectangle. o Initialize the band by filling it with white space. o Call DrawPicture to draw the picture into the band's rectangle. o Do whatever is needed to print the pixel image in the band's rectangle. o Clear the imaging flag. o Calculate the next band's position. o Increment the band's counter and loop back if not done. o If GAP was specified, cause a form feed. o Increment the page count to the next page and loop back if not done. o Increment the number of copies counter and loop back if not done. o Free any buffers that you own and close the port. o Dispose of the information dialog that you put up. o Dispose of each picture in the picture list by calling KillPicture. o Dispose of the picture list itself. o Reset the cursor. PrError ($1413) Description: Gets the error code from the last Print Manager call. Passed: None Returned: LastError WORD Result code from last Print Manager call Performs the following: o Gets the driver's internal error value (which was determined by the last driver call) and sets the return parameter LastError to it. Possible Errors: noError $0000 PrAbort $0080 Indicates print job was aborted $1301 Indicates missing drivers $1302 Indicates Port Not On $1303 Indicates No Print Record $1306 Indicates PAP Connection Not Made $1307 Indicates Read/Write PAP Error $1308 Indicates Printer Connection Failed PrSetError ($1513) Description: Sets the error value. Passed: ErrorNumber WORD Error number to be set Returned: None Performs the following: o Sets the driver's internal error value to the value of the passed ErrorNumber parameter. GetDeviceName ($1713) Description: Used as a communications tool between the printer driver and port driver. Passed: None Returned: None Performs the following: o Calls the port driver routine PrDevPrChanged with the printer name as input. This is necessary for drivers that will work over AppleTalk. The name passed as the parameter to PrDevPrChanged should be what AppleTalk will use in an NBPLookup situation; for AppleTalk, such a name should follow NBP conventions. PrDriverVer ($2313) Description: Returns the version number of the currently installed printer driver. Passed: Wordspace WORD Space for results Returned: versionInfo WORD Printer driver's version number Performs the following: o Gets the internal version number of the printer driver and returns it on the stack at versionInfo. Note: The internal version number is stored major byte, minor byte (i.e., $0103 represents version 1.3) PrGetPrinterSpecs ($1813) Description: Returns the type of printer and the printer's characteristics. Passed: Wordspace WORD Space for results Wordspace WORD Space for results Returned: PrinterType WORD 0 = undefined 1 = ImageWriter or ImageWriter II 2 = ImageWriter LQ 3 = LaserWriter family (except IISC) 4 = Epson $8001 = generic dot matrix printer $8003 = generic laser printer PrCharacteristics WORD Bits 15 - 2 = reserved, must be zero Bits 1-0: 00 = cannot determine 01 = black and white only 10 = color capable Performs the following: o Returns characteristics intrinsic for the printer being supported. PrGetPgOrientation ($3813) Description: Returns the page orientation from the current print record. Passed: Wordspace WORD Space for results Returned: PgOrientation WORD Current page orientation: 0 = portrait 1 = landscape Performs the following: o Returns the page orientation from the current page setup information in the print record. Immediate Mode Procedures To print in the immediate mode, you need to install procedures which will cause printing when you make QuickDraw II calls (as noted in PrOpenPage). This section describes the structure and parameters for these routines. To install the immediate mode procedures, first create a procedure table for sixteen entries (16*4 bytes) and fill it with the standard procedures by calling SetStdProcs. Once you have the standard procedures, install the addresses of your procedures into it and call SetGrafProcs. Installing your procedure addresses will cause the appropriate QuickDraw II calls to call your procedures, which, in turn, will perform the actual printing. The routines that need to be written are known as QuickDraw II "bottleneck procedures." Access to the routines are from bank $E0 (accessed by doing a JSL to the appropriate address in bank $E0). When you call any of the bottleneck procedures, the first direct page of QuickDraw II is active and the following direct page locations are valid: PortRef $24 MaxWidth $20 MasterSCB $08 UserId $0A Two bottleneck procedures, StdText and StdPixels, are of most concern when writing immediate mode procedures. (Refer to Apple IIGS Technical Note #34 for more information on bottleneck procedures.) The routine StdText (standard text) is the standard text drawing routine. To install this routine into your procedure table (as described above), make it the first entry (offset of $00). Once it's installed, you can access it by doing a long call to absolute address $E01E04. Its direct page parameters are as follows: DrawVerb $38 Describes the kind of text to draw. There are three possible values: DrawCharVerb 0 DrawTextVerb 1 DrawCStrVerb 2 TextPtr $DA If the draw verb is DrawTextVerb or DrawCStrVerb, TextPtr points to the text buffer or C string to draw. TextLength $D8 If the draw verb is DrawTextVerb, TextLength contains the number of bytes in the text buffer. CharToDraw $D6 If the draw verb is DrawCharVerb, CharToDraw contains the character to draw. The routine StdPixels is the standard pixelmap drawing routine. To install this routine into your procedure table (as described above), put it at offset $20. Once it's installed, you can access it by doing a long call to absolute address $E01E24. Its direct page parameters are as follows: SrcLocInfo $CC The LocInfo record for the source pixel map DestLocInfo $0C The LocInfo record for the destination pixel map SrcRect $DC The source rectangle for the operation in local coordinates for the source pixel map (as described in the source LocInfo record) DestRect $1C The destination rectangle for the operation in local coordinates for the destination pixel map (as described in the destination LocInfo record) XferMode $E4 The mode to use for data transfer RgnHandleA $50 The handle to the first region to which drawing is clipped (usually the ClipRgn from the GrafPort) A NIL handle is not allowed. To signify no clipping, pass a handle to the WideOpen region, which is defined as 10 bytes: Length $A (word) -MaxInt -$3FFF (word) -MaxInt -$3FFF (word) +MaxInt +$3FFF (word) +MaxInt +$3FFF (word) RgnHandleB $60 The handle to the second region to which drawing is clipped (usually the VisRgn from the GrafPort) A NIL handle is not allowed. To signify no clipping, pass a handle to the WideOpen region. RgnHandleC $70 The handle to the second region to which drawing is clipped (usually the mask region from the CopyPixels or the PaintPixels call) A NIL handle is not allowed. To signify no clipping, pass a handle to the WideOpen region. Example: ;***************************************************************** ;** Example of Immediate Mode Printer Procedures. ** ;***************************************************************** Immedprocs Start SrcRect equ $DC SrcLocInfo equ $CC DrawVerb equ $38 TextPtr equ $da TextLength equ $d8 CharToDraw equ $d6 ;------------------------------------------------------------------ ; ; _StdPixels Procedure (Prints Pixelmaps) ; ;------------------------------------------------------------------ Pixel Entry phb ;save data bank reg on stack phk ;get program bank reg. plb ;use as data bank reg. lda iPrErr ;get errors beq Continue ;branch if none brl ExitPixel ;branch if errors Continue anop ;This gets the source rectangle and stores it at PixelRect ldx #6 MoveSrc lda SrcRect,x sta PixelRect,x dex dex bpl MoveSrc ;This gets the source LocInfo and stores it at PixelLoc ldx #16-2 MoveLI lda SrcLocInfo,x sta PixelLoc,x dex dex bpl MoveLI pushptr PixelLoc ;push pointer to LocInfo pushptr PixelRect ;push pointer to rectangle ;++++++++++++++++++++++ ; Insert code here to print a pixelmap ; INPUT: PixelLoc LONG, Pointer to pixel LocInfo ; PixelRect LONG, Pointer to pixels BoundsRect ; SP-> ;++++++++++++++++++++++ Exitpixel lda #0 ;return with no errors clc plb ;restore data bank rtl ;returnith long PixelLoc ds 16 ;pixel LocInfo PixelRect ds 8 ;pixel rectangle ;------------------------------------------------------------------ ; ; _StdText Procedure (Prints Standard Text) ; ;------------------------------------------------------------------ StdText Entry phb ;save data bank reg on stack phk ;get program bank reg. plb ;use as data bank reg. pushptr PenPos _GetPen ;current pen pos. -> PenPos ;++++++++++++++++++++++ ; Insert Code Here to move the printers head to the corresponding ; PenPos position (if needed). ;++++++++++++++++++++++ pushword #0 ;space for textwidth ;(for call to _TextWidth) lda DrawVerb ;get DrawVerb beq DoCar ;if DrawVerb=0 then DoCar cmp #1 beq Dotext2 ;if DrawVerb=1 then Dotext2 ; ;We get here if it's a "C" string (DrawVerb=2) ; DoCstring anop sep #$20 longa off ;Search down through string looking for terminator to calc. length ldy #0 KeepLooking lda [TextPtr],y beq TheEnd iny bra KeepLooking TheEnd rep #$20 longa on lda TextPtr+2 pha ;push the pointer to string lda Textptr pha phy ;push the length of sting bra Common ; ;We get here if it's just one character (DrawVerb=0) ; DoCar anop pushword #0 tdc clc adc #CharToDraw ;calculate addr. of char. pha ;push addr. of character pushword #1 ;push length of one char. bra Common ; ;We get here if it's a string of text (DrawVerb=1) ; DoText2 anop lda TextPtr+2 pha ;push pointer to the string lda Textptr pha lda TextLength pha ;push the strings length Common lda 5,s ;Dup the last 3 words of pha ;the stack (for _TextWidth) lda 5,s pha lda 5,s pha ;++++++++++++++++++++++ ; Insert code here to print the text ; ; INPUT: TextPointer LONG, Pointer to text to print ; TextLength WORD, No. of bytes to print ; SP-> ;++++++++++++++++++++++ _TextWidth ;get the texts width (DH) pushword #0 ;set (DV)=0 _Move ;move current pen location ExitText lda #0 ;return with no errors clc plb ;restore data bank rtl ;returnith long PenPos ds 4 ;pen position end Further Reference _____________________________________________________________________________ o Apple IIGS Toolbox Reference, Volumes 1 & 2