Hi, (sorry about the reply on webmail hassle)
---------- Original Message ------------- Subject: Re: [Freedos-devel] A dilemma affecting next DISPLAY Date: Wed, 24 Aug 2005 08:55:35 +0200 From: Roberto Mariottini <[EMAIL PROTECTED]> To: [email protected] Aitor Santamaría Merino wrote: > Hi there, > > FD-DISPLAY is about 11KB size (the data for the 3 subfonts, 8x8, 8x14 > and 8x16 is 10.5Kb). MS-DISPLAY is about 5KB resident size (the size of > 8x16 is 4KB). > > Following Eric's step, I can use a single data pool to load the data > into memory (I no need to make room for the three subfonts. I load one > after the other), but I am facing this problem: > > Some Display Adapter interrupt functions (INT 10h) hooked by DISPLAY.SYS > are there to get pointers to font data (yes, get pointers, not filling > user's buffers). If I can only have 5Kb resident, I can only have room > for one subfont permanently in main memory. But how does MS-DOS' display do then? It tries to allocate a new 6.5k of memory? === Reply I would have to test, but I'd say that DISPLAY allocates initially and never grows. > Thus, the only idea that comes to my mind is that I leave there the data > only for the current subfont in use (8x8, 8x14 or 8x16), and the request > for the other pointers are diverted to BIOS. This way one would have the > problem that if your program asks for these pointers, the characters of > each subfont may differ (as BIOS is always codepage 437, it could be > that the character number 200 is one character in 8x8 and another in the > 8x16 font), but I can't come up with other idea, any hints? > > Notice that it's not use to put resident the data for the last requested > subfont, because a program could well retrieve the three pointers at the > very begining and try to use the three of them within the code. I don't understand: the program can use a particular font type regardless of the display mode? === Reply Well, I don't know what a particular program would do. I just know that there are interrupt functions to obtain POINTERS to font data in memory (a parameter specifies whether the program wants the 8x8 the 8x14 or the 8x16 font: my problem is that I cannot give the three pointers pointing to DISPLAY data and guarantee that they point correctly at every time). Aitor ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ Freedos-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-devel
