Spectrum ROM | Routines |
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The address of this routine is found in the table of addresses. It is called indirectly via fp_calc_2.
This subroutine handles the function STR$ X and returns a 'last value' which is a set of parameters that define a string containing what would appear on the screen if X were displayed by a PRINT command.
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str | 13855 | LD BC,1 | One space is made in the work space and its address is copied to K-CUR, the address of the cursor. | ||||
13858 | RST 48 | ||||||
13859 | LD (23643),HL | ||||||
13862 | PUSH HL | This address is saved on the stack too. | |||||
13863 | LD HL,(23633) | The current channel address (CURCHL) is saved on the machine stack. | |||||
13866 | PUSH HL | ||||||
13867 | LD A,255 | Channel 'R' is opened, allowing the string to be 'printed' out into the work space. | |||||
13869 | CALL CHAN_OPEN | ||||||
13872 | CALL PRINT_FP | The 'last value', X, is now printed out in the work space and the work space is expanded with each character. | |||||
13875 | POP HL | Restore CURCHL to HL and restore the flags that are appropriate to it. | |||||
13876 | CALL CHAN_FLAG | ||||||
13879 | POP DE | Restore the start address of the string. | |||||
13880 | LD HL,(23643) | Now the cursor address is one past the end of the string and hence the difference is the length. | |||||
13883 | AND A | ||||||
13884 | SBC HL,DE | ||||||
13886 | LD B,H | Transfer the length to BC. | |||||
13887 | LD C,L | ||||||
13888 | CALL STK_STO | Pass the parameters of the new string to the calculator stack. | |||||
13891 | EX DE,HL | Reset the pointers. | |||||
13892 | RET | Finished. | |||||
Note: see PRINT_FP for an explanation of the 'PRINT "A"+STR$ 0.1' error.
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