XeO3: The games afoot...

Luca and I have been hammering out the how the actual weapon system is going to work and I have to say its one of the few times where internet development really sucks. Trying to chat about something like this and get the details right so that we both agree is hard enough, but having to type every line into Windows Messenger is just a nightmare. If we were in the same room, it could be done in about 5-10 min since we could discuss it easily, draw diagrams on a bits of paper, and basically get to sorted quickly. But over the net, it took us the better part of an hour to go through it and make sure we both understood what the hell we were talking about. Oh well, its all sorted now - I'll let Luca go through it all though.

I've also been trying to figure out how to erase files from a floppy using the kernal. Little bit of a pain, since theres hardly anything telling you how to execute disk commands from assembler. I know you can do this in DOS...

  open 15,8,15,"S0:FILE"
  close 15

But, I wasn't sure how to actually do it in assembler. I finally found some code after a bit of hunting around and this is now what I do...

    lda  #15                   ; file handle
    ldx  #8                    ; device
    tay                        ; command channel
    jsr  SETLFS                ; set channel details
    lda  #8                    ; length of filename ("S0:SCORE")
    ldx  #LO(HISCORENAME)      ; pointer to score
    ldy  #HI(HISCORENAME)
    jsr  SETNAM                ; Set file name
    jsr  OPEN                  ; perform OPEN command
    lda  #15
    jsr  CLOSE                 ; and close the channel

And thats all there is to it. When we have the turbo installed we'll have to issue a save with overwrite and get the turbo (on the disk drive side) to erase the file first. This is all to avoid the SAVE "@0:filename" bug. However, after all this is done, it'll mean we can save hiscores to disk for a proper record - which is cool.