From: ansgar@i3.informatik.rwth-aachen.de (Ansgar Radermacher) Newsgroups: comp.lang.postscript Subject: BJC-610, ghostscript, 720dpi Date: 14 Jun 1996 15:28:14 GMT Organization: Informatik III, RWTH Aachen Message-ID: <4ps0ee$e5p@news.rwth-aachen.de> Hello, there might be good news for the BJC-610 users. I found a bug in gs3.53, which prevents 720 dpi printing (using the bjc600 driver)! I looked closer at the generated printer code from ghostscript in order to compare it with the code from the OS/2 driver. I noticed that the produced code is wrong (here the example for 360 dpi): vv 000020 14 0 1b 28 63 3 0 14 0 0 1b 28 64 2 0> 0< ...(c......(d... 000030 68 1b 28 65 2 0 0 89 1b 28 41 31 0 4b 0 40 h.(e.....(A1.K.@ The code marked at the end of the first line, contains the higher byte for the resolution setting. In this case 360 dpi should led to 1 68 (and not 0 68). This bug has (strangely) no effect for 360 dpi, but prevents 720 dpi printing. A look at the code revealed the reason for this error: resolution[0] = ((byte) pdev->x_pixels_per_inch) / 256; // always 0 !! resolution[1] = ((byte) pdev->x_pixels_per_inch) % 256; which might be changed to: resolution[0] = (byte) ((int) pdev->x_pixels_per_inch / 256); resolution[1] = (byte) ((int) pdev->x_pixels_per_inch % 256); After applying this patch call gs with the explicit option -r720x720. I have just started to make first tests on plain paper. The output looks too dark (higher resolution => more ink?), maybe more fine tuning is needed. I don't know, if additional undocumented commands --e.g. to control the dot-size-- are needed. Ansgar -- Ansgar Radermacher \\ Department of Computer Science III mailto:ansgar@i3.Informatik.RWTH-Aachen.DE \\ University of Technology, Aachen \\ Ahornstr. 55 phone: +49 241 8021 311 \\ 52074 Aachen fax: +49 241 8888 218 `-------------------------------- www: http://hobbes.informatik.rwth-aachen.de/~ansgar