Marcos, that is not exactly trivial to do portably over all QDOSMSQ platforms. Below a recipe how I do it:
Check for PE (IOP.PINF). If available, screen extent is easy: you can get scr_xlim and scr_ylim via the IOP.FLIM PE call. (If not, xlim is a bit more difficult and ylim not 100% possible afaik) open a con_ channel (or use channel id 0, which might give you wrong info on Minerva) Get System Variable address (MT.INF) get the channel table address from SV_CHBAS from system variables Walk the channel table starting at that address, looking for the tag part of your channel id from (2) in $10. Some people simply take the first channel table entry, which is for con_ #0 most of the time….. But sometimes it isn't... once you found your channel, look into sd_scrb (or scr_base, $32 from start of that con_ channel definition block) and scr_llen at $64 from start If you don’t have PE, scr_xlim can be derived from the current mode (which gives you bits per pixel, 2==Mode 4, 4 == Mode 8, 8 ==Mode 256,…) . You simply divide scr_llen * 8 by the # of bits/pixel and get the number of pixels per line. I currently have no idea how to properly get at scr_ylim without PE - My code normally just guesses from the above. The only platform that does not necessarily have PE loaded (because of SMSQ/E) and still supports other than the standard QL resolutions is uqlx, to my knowledge. For the exact layout of the data structures, have a look at the QL Technical guide or the QDOS/SMSQ Reference Manual. Hope this helps, Tobias > Am 13.01.2016 um 21:26 schrieb Marcos Cruz <[email protected]>: > > Hi all, > > I need some help. > > Which is the easiest way to get the screen info from assembly is SMSQ/E? > I mean, what `scr_base`, `scr_xlim`, `scr_ylim` and `scr_llen` do in > SBASIC. > > I've found the code of those keywords in the SMSQ/E sources, and I'm > studying it in order to remove the SBASIC stuff, but I'm wondering if > someone has done this before. > > Thanks. > > -- > Marcos Cruz > http://programandala.net > _______________________________________________ > QL-Users Mailing List _______________________________________________ QL-Users Mailing List
