8



     size on powerup. On DOS boot, RAMLO and TRAMSZ also act as
     temporary storage for the boot continuation address. TRAMSZ
     and TSTDAT are used later to flag whether or not the A (left)
     and/or B (right) cartridges, respectively, are plugged in (non-
     zero equals cartridge plugged in) and whether the disk is to be
     hooted.

Locations eight through 15 ($8-$F) are cleared on coldstart only.

8              8              WARMST
     Warmstart flag. If the location reads zero, then it is in the middle
     of powerup; 255 is the normal RESET status. Warmstart is similar
     to pressing RESET, so should not wipe out memory, variables, or
     programs. WARMST is initialized to zero and will not change
     values unless POKEd or until the first time the RESET button is
     pressed. It will then read 255 ($FF).

     Warmstart normally vectors to location 58484 ($E474). WARMST
     is checked by the NMI status register at 54287 ($D40F) when
     RESET is pressed to see whether or not to re-initialize the
     software or to re-boot the disk.

9              9              BOOT?
     Boot flag success indicator. A value of 255 in this location will
     cause the system to lockup if RESET is pressed. If BOOT? reads
     one, then the disk boot was successful; if it reads two, then the
     cassette boot was successful. If it reads zero, then neither
     peripheral was booted.

     If it is set to two, then the cassette vector at locations two and
     three will be used on RESET. Set to one, it will use the DOS
     vector at 10 and 11 ($A and $B). Coldstart attempts both a
     cassette and a disk boot and flags this location with the success or
     failure of the boots. BOOT? is checked during both disk and
     cassette boot.

10,11          A,B            DOSVEC
     Start vector for disk (or non-cartridge) software. This is the
     address BASIC jumps to when you call up DOS. Can be set by
     user to point to your own routine, but RESET will return DOSVEC
     to the original address. To prevent this, POKE 5446 with the LSB
     and 5450 with the MSB of your vector address and re-save DOS
     using the WRITE DOS FILES option in the menu. Locations 10
     and 11 are usually loaded with 159 and 23 ($9F and $17),
     respectively. This allows the DUPSYS section of DOS to be
     loaded when called. It is initially set to blackboard mode vector
     (58481; $E471--called by typing "BYE" or "B." from BASIC); it
     will also vector to the cassette run address if no DOS vector is
     loaded in. If you create an AUTORUN.SYS file that doesn't end