mdcg7180@uxa.cso.uiuc.edu (Michael David Carr) (06/21/91)
I'm new to C, so if I'm overlooking the obvious, please bear with me.
I'm trying to print graphics on a DeskJet+, and am having no problems
except that I can't send ASCII 26 in a string of graphics bytes.
For those not familiar with the Deskjet (but C pros), to print a
row of graphics pixels, you must first put the printer in graphics
mode (I did that). Then send it an Escape, and the following string:
*b###W (... data bytes)
where ### is the number of data bytes that follow.
The data bytes represent 8 pixels, and can take on values from
0 to 255. I can print any byte except ASCII 26!
It isn't the printer, because I can send a 26 in BASIC and
FORTRAN.
Any help would be greatly appreciated (HP and Borland have no clue).
Michael Carr
mdcg7180@uxa.cso.uiuc.edu
Graduate Engineering, U. of I. at Urbana-Champaigncraigg@hpwrce.HP.COM (06/22/91)
Mike, I just tried to duplicate your problem using Microsoft QuickC. The DeskJet worked fine with the QuickC code. I don't have Turbo C or C++ installed on my office system. I will try it at home this weekend. BTW... You really don't need to set the printer for graphics mode, unless you are changing the default resolution. However, it is a good practice to get into. I will follow up on Monday... =============================================================================== |Craig Gilmore | "I know GOD is a man, 'cause the first | |Hewlett-Packard Response Center | thing created was DIRT. A woman would | |craigg@hpwrce.HP.COM | have created a DUSTBUSTER..." -Gallager | |These are MY opinions, HP only pays me to answer questions and solve problems| ===============================================================================
frank@cavebbs.gen.nz (Frank van der Hulst) (06/22/91)
In article <1991Jun21.040657.3195@ux1.cso.uiuc.edu> mdcg7180@uxa.cso.uiuc.edu (Michael David Carr) writes: >I'm trying to print graphics on a DeskJet+, and am having no problems >except that I can't send ASCII 26 in a string of graphics bytes. > >Any help would be greatly appreciated (HP and Borland have no clue). The problem lies with TC++ (and TC and Turbo-Pascal going back at least 5 years). The stdprn stream is opened as text mode, not binary, so a \x1A acts as an EOF character (just like a disk text file). You need to re-open stdprn in binary mode. I have code (elsewhere) which does this by doing a DOS call via int 21h (from vague memory) because TC won't allow you to change the device's mode. I can post the code (its only about 10 lines) if you need it. Frank. -- Take a walk on the wild side, and I don't mean the Milford Track. Kayaking: The art of appearing to want to go where your boat is taking you.
frank@cavebbs.gen.nz (Frank van der Hulst) (06/23/91)
>The problem lies with TC++ (and TC and Turbo-Pascal going back at least 5 Oops -- minor mistake. The problem relates to MS-DOS, going back several years. >years). The stdprn stream is opened as text mode, not binary, so a \x1A acts >as an EOF character (just like a disk text file). You need to re-open stdprn >in binary mode. I have code (elsewhere) which does this by doing a DOS call Doing open() or whatever from C won't work -- here's the code (in assembler), although doing the same in C via intdos() should work fine.: ; bin_mode: ; int far bin_mode(int handle); ; Change device into binary mode. ; Assemble via TASM /mx BIN_MODE ; DOS always ignores the binary parameter ("b") on device opens - LPT1, ; etc. You have to follow the open with an IOCTL call to get the output ; device operating in binary mode. Note that it needs the result of an ; sopen(), open() or fdopen() call. _bin_mode proc far handle: word push bp mov bp, sp mov ax, 4400h ; Read device info mov bx, handle ; file handle from open int 21h ; Get device data into DX jc exit ; Check whether valid and dl, 80h ; Is this a file or device ? jz exit_OK ; If file, do nothing mov ax, 4401h ; Set device parms mov bx, handle xor dh, dh ; Clear high byte or dl, 20h ; Ignore control characters, incl. ^Z int 21h jc exit exit_OK:xor ax, ax exit: pop bp ret > -- Take a walk on the wild side, and I don't mean the Milford Track. Kayaking: The art of appearing to want to go where your boat is taking you.
rob@pact.nl (Rob Kurver) (06/23/91)
In <1991Jun22.080947.504@cavebbs.gen.nz> frank@cavebbs.gen.nz (Frank van der Hulst) writes: >In article <1991Jun21.040657.3195@ux1.cso.uiuc.edu> mdcg7180@uxa.cso.uiuc.edu (Michael David Carr) writes: }>I'm trying to print graphics on a DeskJet+, and am having no problems }>except that I can't send ASCII 26 in a string of graphics bytes. }> }>Any help would be greatly appreciated (HP and Borland have no clue). }The problem lies with TC++ (and TC and Turbo-Pascal going back at least 5 }years). The stdprn stream is opened as text mode, not binary, so a \x1A acts }as an EOF character (just like a disk text file). You need to re-open stdprn }in binary mode. I have code (elsewhere) which does this by doing a DOS call }via int 21h (from vague memory) because TC won't allow you to change the }device's mode. Can't you just ignore stdprn and simply open a new stream to the printer in binary mode? Cheers. - Rob -- PACT Rob Kurver Foulkeslaan 87 rob@pact.nl 2625 RB Delft tel: +31 15 616864 The Netherlands fax: +31 15 610032