----- Original Message ----- From: "Carl Nordlund" <carl@xxxxxxxxxxx> Newsgroups: comp.sys.sinclair Sent: Tuesday, July 13, 2004 1:28 PM Subject: New Speccy game (mc) being developed > Hi all, > > Just found my way back home to the Spectrum scene and boy am I happy to note > all this activity going on! > > Although I should be writing on my PhD, I have decided to finish off an old > game I worked on for about 15 years ago. It's called Ragnar and is a 3d > isometric platform Kirel/Alien8-style game. A demo is available here for > download (no play though, just a moving character) as I just learned how to > convert tapes to the pc: > > http://www.humecol.lu.se/carl_n/ragnar.html > > I am still very proud that I actually wrote this back then, being only about > 15-16 years old, and just using the Lerm Assembler and some books in the > english foreign language! > > And now I have a loading screen too - made just the other day! > > http://www.humecol.lu.se/carl_n/frontscr.bmp > > However, I am actually more or less recoding the whole game - it's so easy > to do all this with TASM and emulators and stuff instead of Lerm:ing on my > +2... > > However, as the only book I can find is "Spectrum Machine Language for the > Absolute Beginner", as well as an old Zilog Z80 specification book I got, I > still miss info on memory handling on the Spectrum. > > What I need right now is a structural memory description of the Speccy. What > about system variables - if I remember correctly, they are to be found right > after scr and attr memory (23296?), correct? But as I won't be using any ROM > routines, I could just ignore these could I and placing my code and data > right smack at 23296 - no? > > And I find stuff by default up at the top of the memory - peeking around at > 65500 returns data. Are the UDG located here or anything else? > > I will probably need some more assistance in the upcoming weeks too, for > instance on how to write the main game loop where I should be checking the > vertical raster counter (Sysvar, IN or where/how do I get the value of this > one?) Also, I wonder what the best way is to store integers in such as score > etc, suitable for displaying (in dec format, not hex or bin that is!). On > another game I did back then, I wrote my own number handlers, with a byte > for each "decimal place" (for instance where the number 14340 was stored in > 5 cells, holding 1, 4, 3, 4 and 0 respectively). Because how do I make it > possible to count above 65535 and how do I display ordinary 16-bit numbers > as decimals (there are bcd-to-dec formulas if I remember correctly but I > never understood the principles on how to use them - hey, I was only a kid > then!) > > Yours, > Carl > >