Alhart Enterprises Presents¢ MagiCalc XL by: Paul V. Alhart¢¢MagiCalc XL is a SHAREWARE program designed and written to remain resident in the extended RAM of a 256K XL/XE Atari that uses the 130XE or RAMBO XL bank switching scheme. (Switching address $D301). It was developed for use with SmartDOS 8.2D and up to two single density RAMdisks although it can be used with other DOSs and even with a stock 130XE.(See COMPATIBILITY below). It is RESET proof and uses a portion of the 12K of extended RAM not used by the RAMdisks.¢¢¢WHAT IS IT?¢¢MagiCalc is a four function calculator that remains resident in extended RAM. Just a key stroke is all that is required to halt your Atari's current operation and turn your keyboard into a calculator. Upon exiting the calculator, your machine will return to what it was doing prior to entering the MagiCalc. MagiCalc allows entries to be made in decimal, hex, and scientific notation (12E+09). Mixed numbering system math is supported. For example you can divide $A02C by 1234E-06 or subtract 1234.56 from -$302D. All valid entries and results are displayed in decimal, hex, and binary so numbering system conversions by the user are unnecessary. MagiCalc also supports PEEKs and double PEEKs (Location + Location+1 * 256) without altering the calculator's memory.¢¢GETTING STARTED¢¢MagiCalc.XL should be copied to your boot disk and renamed so that it will load as an AUTORUN.SYS file. If you try to load it as a binary file from DOS the keyboard will lock up. In this event, pressing RESET will allow the code to complete its initialization and restore the keyboard to normal operation. Once the boot process is complete MagiCalc remains hidden away in extended RAM until it is called by simultaneously pressing the SHIFT-CONTROL-TAB keys. This can be done from BASIC, Turbo BASIC, PILOT, DOS, etc. MagiCalc can even be called while some programs are running, providing they are not doing I/O to an external device at the time.¢¢¢USING MAGICALC XL¢¢To enter MagiCalc press the SHIFT, CONTROL, and TAB keys, all at the same time. The screen will turn black and the calculator's memory (Zero at start up) will be displayed in decimal, hex, and binary notation.¢¢The following is a list of valid entry formats for MagiCalc. Each entry must be followed by pressing RETURN. Notice that + signs are unnecessary but can be used if desired. Hex numbers must be preceded by a "$".¢¢ENTRY OPERATION¢¢dddddd Add a positive decimal # to calculator's memory.¢+ddddd Add a positive decimal # to memory.¢+-dddd Add a negative decimal # to memory.¢-ddddd Subtract a positive decimal # from memory.¢-+dddd Subtract a positive decimal # from memory.¢--dddd Subtract a negative decimal # from memory.¢*ddddd Multiply a positive decimal # by memory.¢*+dddd Multiply a positive decimal # by memory.¢*-dddd Multiply a negative decimal # by memory.¢/ddddd Divide memory by a positive decimal #.¢/+dddd Divide memory by a positive decimal #.¢/-dddd Divide memory by a negative decimal #.¢¢$hhhh Add a positive hex # to memory.¢+$hhhh Add a positive hex # to memory.¢-$hhhh Subtract a positive hex # from memory.¢*$hhhh Multiply a positive hex # by memory.¢/$hhhh Divide memory by a positive hex #.¢¢ ddddd PEEK & DOUBLE PEEK decimal location (ddddd).¢ $hhhh PEEK & DOUBLE PEEK hex location (hhhh).¢¢ESCAPE Clears calculator memory.¢SHIFT-ESCAPE Exits MagiCalc mode.¢¢NOTE: Entries preceded by a space are assumed to be memory locations that will be PEEKed. Therefore these entries must be positive integers within the range of 0 to 65535 ($0 to $FFFF).¢¢NOTE: Only positive entries and results between 0 and 65535 ($0 and $FFFF) will be displayed as hex and binary integers. All hex and binary integers are rounded off to the nearest whole number.¢¢¢COMPATIBILITY¢¢MagiCalc XL can be used with any AtariDOS 2 compatible DOS that supports an AUTORUN.SYS file.¢MagiCalc uses a portion of page 6 RAM for its keyboard handler and the code used for memory bank switching. Programs or cartridges that use page 6 RAM may be in conflict with MagiCalc.¢SmartDOS 8.2D with two 707 sector RAMdisks leaves 12K of extended RAM unused on a 256K machine. NOTE: AtariDOS 2.5 & RAMDISK.COM do not use this portion of memory either. The MagiCalc program itself resides in this unused RAM. Programs or RAMdisks that use all extended memory will be in conflict with MagiCalc.¢MagiCalc will run on a stock 130XE as long as a RAMdisk is not booted. A RAMdisk will use all the extended RAM of a 128K 130XE.¢¢MagiCalc can be called while some programs are running. The screen will be cleared before MagiCalc passes control back to the program however. If this causes problems, first stop the program by pressing BREAK or RESET and then enter MagiCalc.¢¢¢TECH TALK¢¢MagiCalc runs as if it were a Keyboard Interrupt Routine. MagiCalc's keyboard handler and bank switching code occupies 126 bytes of page 6. It was assembled starting at location $0680 (last half of page 6) to be as conflict free with other software as possible. This code could be easily reassembled to another area in main memory by changing the origin value in the source code. Source Code Line Number (SCLN) 0620.¢The MagiCalc code resides in memory bank 9. On a stock 130XE this would be the General Extended RAM Mode 0 Bank 1. It was assembled from $7000 to $7412 within this memory bank. Again, the bank and where the code is placed within the bank can be tailored to your own system or liking by changing the following values and reassembling.¢¢SCLN 0550 (BANKSELECT = $44) This value is used to modify bits 2-6 in the PORTB register at SCLN 1350.¢¢SCLN 0570 (MYPROGRAM) = $7000 This resets the assembly origin to $7000 when called at SCLN 1620.¢¢¢TECH SUPPORT¢¢Tech support is available for all registered owners. Your questions and comments are welcome as well and may be of help with future programs or revisions of MagiCalc XL. Also, please let me know where you came across MagiCalc XL.¢¢To register please send $6.00.¢¢To register and receive a disk containing MagiCalc XL, Documentation, and the complete, heavily commented MAC65 source code, please send $10.00 to:¢¢Paul V. Alhart¢524 North Zee St.¢Lompoc, Ca. 93436¢
