48551



48551          BDA7           SIN
     Calculate SIN(FR0). Checks DEGFLG (location 251; $FB) to see if
     trigonometric calculations are in radians (DEGFLG equals zero)
     or degrees (DEGFLG equals six).

48561          BDB1           COS
     Calculate Cosine (FR0) with carry. FR0 is Floating Point register
     zero, locations 212-217; $D4-$D9. See the Floating Point package
     entry points from location 55296 on.

48759          BE77           ATAN
     Calculate Atangent using FR0, with carry.

48869          BEE5           SQR
     Calculate square root (FR0) with carry.
     Note that there is some conflict of addresses for the above
     routines. The addresses given are from the first edition of De Re
     Atari. The Atari OS Source Code Listing gives the following
     addresses for these FP routines:

     These are entry points, not actual start addresses.

     SIN     48513   ($BD81)
     COS     48499   ($BD73)
     ATAN    48707   ($BE43)
     SQR     48817   ($BEB1)

     However, after disassembling the BASIC ROMs, I found that the
     addresses in De Re Atari appear to be correct.

49146,7        BFFA,B
     Left cartridge start address.

49148          BFFC
     A non-zero number here tells the OS that there is no cartridge in
     the left slot.

49149          BFFD
     Option byte. A cartridge which does not specify a disk boot may
     use all of the memory from 1152 ($480) to MEMTOP any way it sees
     fit.

49150,1        BFFE,F
     Cartridge initialization address. See the above section on the right
     slot, 32768 to 40959, for more information.

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     When a BASIC program is SAVEd, only 14 of the more than 50
     page zero locations BASIC uses are written to the disk or cassette
     with the program. The rest are all recalculated with a NEW or
     SAVE command, sometimes with RUN or GOTO. These 14