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Beepola vector tables

daveysludgedaveysludge
edited November 2013 in Development
What are the 'interrupt vector tables' at FE00?

Is it interfering with my other routines at 65000 onwards?

will setting the IVT to ROM make any difference?
Post edited by daveysludge on

Comments

  • utzutz
    edited November 2013
    These are used by the IM2 custom interrupt routines present in ClickFuzz and Savage. Yes, they will be written to RAM from FE00 to (I think) FF00.
    I don't know about actual differences when setting the IVT to ROM. However in my experience it is not very reliable and may crash.
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  • daveysludgedaveysludge
    edited November 2013
    utz wrote: »
    These are used by the IM2 custom interrupt routines present in ClickFuzz and Savage. Yes, they will be written to RAM from FE00 to (I think) FF00.
    I don't know about actual differences when setting the IVT to ROM. However in my experience it is not very reliable and may crash.

    I've set it to ROM and it seems stable enough... Fingers crossed!
  • R-TapeR-Tape
    edited November 2013
    daveysludge wrote: »
    What are the 'interrupt vector tables' at FE00?

    Is it interfering with my other routines at 65000 onwards?

    Yep This will insert 257 bytes at 65024 and a few more bytes further up, so if you have any code there it will be overwritten.
    daveysludge wrote: »
    will setting the IVT to ROM make any difference?

    Although the ROM option will not overwrite any of your code it won't work on the +2A and +3 (I think anyway).

    If your program isn't huge your best bet might be to start at 32768* (looking at your previous stuff I think you start at 48000 don't you?) and using the FE00 option.

    *this allows 32k, and you could go even lower of course.
    My speccy games.
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