well that really was obvious i mean it says that in the technical manual on page one doesnt it so it must be dead easy to rewrite a spectrum emulator and use 64 spectrum mode 1 screens and splurge the 128k spectrum code into the gaps between the screens and make use of much faster routines as you know have 64 speccy screens to play with for multiple sprite effects otr making the drawing of the 10 lemmings in ohnofart!? a simple matter of changing the video page register and you'll have 100 animated lemmings on screen by only needing ot redraw the first lemming on screen and redraw only those that have moved if the screen has been scroilled to the left or right casuing some of the wee shites to have to be moved as the scnerey has moved and their vertical postiton means they are out of the stream but even then with 64 screen buffers we'd soon have the wee shites flying along at 50 frames again how about some ½pixels like in the 128 version when they commit hari kari can all 100 lemmings have a half pixel foot at the same time or am i dreaming it guess the extra screens wouldnt help for polygons either woudl they?
2009/9/3 Andrew Collier <[email protected]>: > > On 3 Sep 2009, at 09:25, Andrew Park wrote: > >> Hello >> >> I want to use JPUT (&0133) to display my graphics to compare speed with my >> own routine, on a 512K Sam where is the default screen page stored? >> >> I understand that as long as the graphics are between 16384 and 32767 or >> above 57344 in the screen page that should be fine but where in the 512k >> memory is the default screen page? I’ve calculated where it is but what i >> can see is it goes past the 512k boundary so loses the data. > > The screen will be in pages 30 and 31 by default. In modes 3 and 4 the > screen is 24k in size, so the address of the top of the screen will be at > offset 8192 in page 31. > > Because BASIC starts page 0 at the address 16384, the BASIC address of the > top of the screen will be at (31+1)*16384 + 8192 = 532480. > > Andrew > > > >
