Robert, When not put Minerva into your machine, then you will have a faster operating system than JS or earlier and the second screen is working.
Derek Robert Newson wrote: > omega wrote: > > >> Hello all, >> >> I want to present kind of "demo" for QL on the retro-computing >> competition called Forever see: http://forever.zeroteam.sk >> I did some graphics already on PC and it looks good (looks cool in fact >> :-). But, I need to write special screen hadler with following conditions: >> >> 1) I need to use both screens of the QL without affecting of the 2nd >> screen by system variables. >> (if there must be some variables, how much is the minimum for >> functionality interrupt handler?) >> 2) I still need to call my routine every interrupt (50/60Hz) >> 3) It must run on unexpanded QL with standard QDOS (sandyQboard >> optional), no aurora, no Q40, Q60, no (S)GC. Plain, pure, virging QL only. >> 4) Safe return to Qdos is not required. >> > > >> Anyone has any idea if it's possible? >> > > Have you/can you get your paws on a copy of the Advanced QL User Guide by > Adrian Dickens (ISBN 0 947929 00 2)? > > On Pg 289-292 [of my copy] is a description of the second screen on the QL > plus an assembler program to add pSeudoBASIC extensions to toggle the > display. It notes that the system variables splat over the top 1/5(ish) of > the screen 1 and so keeps screen 0 displaying the top 1/5(ish) and then > displays the required screen (0/1) for the bottom 4/5(ish). > > The active code allocates 0x6be0 bytes from the common heap which should be > allocated in the memory screen 1 uses (to prevent any other program getting > it). It then uses a routine added to the 50/60Hz interrupt to switch > screens as required. > _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
