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system_routines:math [2016/06/05 16:35] ex_writer [INDEXN] |
system_routines:math [2016/06/14 10:42] (current) ex_writer [DSMG] |
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| Undocumented routines are marked with an asterisk (*) | Undocumented routines are marked with an asterisk (*) | ||
| + | |||
| + | <WRAP todo>Need documentation for most math routines</WRAP> | ||
| ^ Name ^ Description ^ | ^ Name ^ Description ^ | ||
| - | | [[#bcdadd|BCDADD]]* | BCD add | | + | | [[#BCDADD]]* | BCD add | |
| - | | [[#bcdchs|BCDCHS]]* | BCD change sign | | + | | [[#BCDCHS]]* | BCD change sign | |
| | [[#bcddiv|BCDDIV]]* | BCD divide | | | [[#bcddiv|BCDDIV]]* | BCD divide | | ||
| | [[#bcdmul|BCDMUL]]* | BCD multiply | | | [[#bcdmul|BCDMUL]]* | BCD multiply | | ||
| Line 35: | Line 37: | ||
| | Calling Sequence: | <code z80>SYSTEM BCDADD</code> or <code z80>SYSSUK BCDADD | | Calling Sequence: | <code z80>SYSTEM BCDADD</code> or <code z80>SYSSUK BCDADD | ||
| - | DW () | + | DW (arg 1) |
| - | DW () | + | DB (size/2 + 1) |
| - | DB ()</code>| | + | DW (arg 2)</code>| |
| | Arguments: | B = SIZE/2 + 1\\ DE = Argument 1\\ HL = Argument 2 | | | Arguments: | B = SIZE/2 + 1\\ DE = Argument 1\\ HL = Argument 2 | | ||
| | Output: | DE = Answer | | | Output: | DE = Answer | | ||
| Line 45: | Line 47: | ||
| BCD CHANGE SIGN | BCD CHANGE SIGN | ||
| + | |||
| + | | Calling Sequence: | <code z80>SYSTEM BCDCHS</code> or <code z80>SYSSUK BCDCHS | ||
| + | DB () | ||
| + | DW ()</code>| | ||
| + | | Arguments: | B =\\ HL = | | ||
| + | | Output: | | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== BCDDIV ==== | ==== BCDDIV ==== | ||
| BCD DIVISION | BCD DIVISION | ||
| + | |||
| + | | Calling Sequence: | <code z80>SYSTEM BCDDIV</code> or <code z80>SYSSUK BCDDIV | ||
| + | DW (arg 1) | ||
| + | DB () | ||
| + | DW (arg 2)</code>| | ||
| + | | Arguments: | B = \\ DE = \\ HL = Argument 2 | | ||
| + | | Output: | ??? | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== BCDMUL ==== | ==== BCDMUL ==== | ||
| BCD MULTIPLY | BCD MULTIPLY | ||
| + | |||
| + | | Calling Sequence: | <code z80>SYSTEM BCDMUL</code> or <code z80>SYSSUK BCDMUL | ||
| + | DW (arg 1) | ||
| + | DB () | ||
| + | DW (arg 2)</code>| | ||
| + | | Arguments: | B =\\ DE =\\ HL = | | ||
| + | | Output: | DE = Answer | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== BCDNEG ==== | ==== BCDNEG ==== | ||
| BCD NEGATE TO DECIMAL | BCD NEGATE TO DECIMAL | ||
| + | |||
| + | | Calling Sequence: | <code z80>SYSTEM BCDNEG</code> or <code z80>SYSSUK BCDNEG | ||
| + | DW () | ||
| + | DB ()</code>| | ||
| + | | Arguments: | B =\\ DE = | | ||
| + | | Output: | ??? | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== BCDSUB ==== | ==== BCDSUB ==== | ||
| BCD SUBTRACTION | BCD SUBTRACTION | ||
| + | |||
| + | | Calling Sequence: | <code z80>SYSTEM BCDSUB</code> or <code z80>SYSSUK BCDSUB | ||
| + | DW (arg 1) | ||
| + | DB () | ||
| + | DW (arg 2)</code>| | ||
| + | | Arguments: | B =\\ DE =\\ HL = | | ||
| + | | Output: | DE = Answer | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== DABS ==== | ==== DABS ==== | ||
| DECIMAL ABSOLUTE VALUE | DECIMAL ABSOLUTE VALUE | ||
| + | |||
| + | | Calling Sequence: | <code z80>SYSTEM DABS</code> or <code z80>SYSSUK DABS | ||
| + | DW () | ||
| + | DB ()</code>| | ||
| + | | Arguments: | B =\\ DE = | | ||
| + | | Output: | | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== DADD ==== | ==== DADD ==== | ||
| DECIMAL ADDITION | DECIMAL ADDITION | ||
| + | |||
| + | | Calling Sequence: | <code z80>SYSTEM DADD</code> or <code z80>SYSSUK DADD | ||
| + | DW (arg 1) | ||
| + | DB () | ||
| + | DW (arg 2)</code>| | ||
| + | | Arguments: | B = \\ DE = \\ HL = | | ||
| + | | Output: | ??? | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== DSMG ==== | ==== DSMG ==== | ||
| DECIMAL CONVERT TO SIGN MAGNITUDE | DECIMAL CONVERT TO SIGN MAGNITUDE | ||
| + | |||
| + | | Calling Sequence: | <code z80>SYSTEM DSMG</code> or <code z80>SYSSUK DSMG | ||
| + | DW (arg 1) | ||
| + | DB (size/2 + 1)</code>| | ||
| + | | Arguments: | B = \\ DE = | | ||
| + | | Output: | ??? | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== INDEXB ==== | ==== INDEXB ==== | ||
| Line 109: | Line 179: | ||
| DW (source)</code>| | DW (source)</code>| | ||
| | Arguments: | DE = Destination address\\ HL = Source address\\ BC = Number of bytes to transfer | | | Arguments: | DE = Destination address\\ HL = Source address\\ BC = Number of bytes to transfer | | ||
| - | | Notes: | None | | ||
| | Description: | MOVE uses LDIR to copy bytes from source to destination. | | | Description: | MOVE uses LDIR to copy bytes from source to destination. | | ||
| - | | Restrictions: | None | | + | |
| ==== NEGT ==== | ==== NEGT ==== | ||
| DECIMAL NEGATE | DECIMAL NEGATE | ||
| + | | Calling Sequence: | <code z80>SYSTEM NEGT</code> or <code z80>SYSSUK NEGT | ||
| + | DB (B) | ||
| + | DW (HL)</code>| | ||
| + | | Arguments: | B =\\ HL = | | ||
| + | | Output: | ??? | | ||
| + | | Notes: | None | | ||
| + | | Description: | | | ||
| ==== RANGED ==== | ==== RANGED ==== | ||
| Line 124: | Line 200: | ||
| | Arguments: | A = Range | | | Arguments: | A = Range | | ||
| | Output: | A = Random Number (0 to Range - 1) | | | Output: | A = Random Number (0 to Range - 1) | | ||
| - | | Notes: | If N is a power of 2, it is considerably faster to use N=0, which causes an 8-bit value to be returned without ranging. Use an AND instruction to range it yourself.\\ \\ RANGED uses a polynomial shift register RANSHT in [[system rom#system ram memory cells|system RAM]]. RANGED is called in [[human interface#getnum|GETNUM]] while waiting for game selection/parameter entry. Thus each execution of a program will receive different random numbers. For 'predictable' random numbers, alter RANSHT yourself after parameter acceptance. | | + | | Notes: | If N is a power of 2, it is considerably faster to use N=0, which causes an 8-bit value to be returned without ranging. Use an AND instruction to range it yourself.\\ \\ RANGED uses a polynomial shift register RANSHT in [[software:system rom#system ram memory cells|system RAM]]. RANGED is called in [[human interface#getnum|GETNUM]] while waiting for game selection/parameter entry. Thus each execution of a program will receive different random numbers. For "predictable" random numbers, alter RANSHT yourself after parameter acceptance. | |
| | Description: | Returns a ranged random number. | | | Description: | Returns a ranged random number. | | ||
| - | | Restrictions: | None | | ||
| ==== SETB ==== | ==== SETB ==== | ||
| Line 153: | Line 228: | ||
| | Calling Sequence: | <code z80>SYSTEM ????</code>| | | Calling Sequence: | <code z80>SYSTEM ????</code>| | ||
| | Arguments: | | | | Arguments: | | | ||
| - | | Notes: | Currently undocumented | | + | | Notes: | | |
| | Description: | Shift up digit in A | | | Description: | Shift up digit in A | | ||
| - | | Restrictions: | None | | ||
| ==== STOREN ==== | ==== STOREN ==== | ||
| Line 163: | Line 237: | ||
| DW (base address)</code>| | DW (base address)</code>| | ||
| | Arguments: | C = Nibble displacement (not loaded)\\ HL = Base address\\ A = Nibble value to store (not loaded) | | | Arguments: | C = Nibble displacement (not loaded)\\ HL = Base address\\ A = Nibble value to store (not loaded) | | ||
| - | | Description: | STOREN is the inverse of [[math routines#indexn|INDEXN]] but functions identically. | | + | | Description: | STOREN is the inverse of [[#INDEXN]] but functions identically. | |
