Routines
Prev: 27570 Up: Map Next: 27671
27572: Compute the decimal digits of a number
Used by the routines at 29613 and 29716. Computes the ASCII codes for the digits of the number held in DE, and stores them in the buffer at 58112.
Input
DE Number
27572 LD HL,58123
27575 LD B,L B=11
27576 DEC L Clear the buffer at 58112, which will be used to store the ASCII codes of the digits
27577 LD (HL),0
27579 DJNZ 27576
27581 LD A,48 48 is the code for '0'
Before inserting any ASCII codes into the buffer, we need to figure out whether the first digit is the 10000s, 1000s, 100s, 10s or units digit.
27583 LD BC,55536 BC=-10000
27586 EX DE,HL DE=58112
27587 ADD HL,BC Subtract 10000
27588 JR C,27620 Jump if it 'went'
27590 SBC HL,BC Otherwise add the 10000 back
27592 LD BC,64536 BC=-1000
27595 ADD HL,BC Subtract 1000
27596 JR C,27633 Jump if it 'went'
27598 SBC HL,BC Otherwise add the 1000 back
27600 LD BC,65436 BC=-100
27603 ADD HL,BC Subtract 100
27604 JR C,27646 Jump if it 'went'
27606 SBC HL,BC Otherwise add the 100 back
27608 LD C,246 BC=-10
27610 ADD HL,BC Subtract 10
27611 JR C,27658 Jump if it 'went'
27613 SBC HL,BC Otherwise add the 10 back
27615 LD A,L A=units left
27616 AND A Are there any?
27617 RET Z Return if not (nothing to do)
27618 JR 27666 Jump forward to place the units digit into the buffer
Compute and insert the 10000s digit.
27620 INC A Get the ASCII code for the 10000s digit in A
27621 ADD HL,BC
27622 JR C,27620
27624 SBC HL,BC
27626 LD BC,64536 BC=-1000
27629 LD (DE),A Place the 10000s digit into the buffer
27630 LD A,47
27632 INC E Move DE along to the next slot in the buffer
Compute and insert the 1000s digit.
27633 INC A Get the ASCII code for the 1000s digit in A
27634 ADD HL,BC
27635 JR C,27633
27637 SBC HL,BC
27639 LD BC,65436 BC=-100
27642 LD (DE),A Place the 1000s digit into the buffer
27643 LD A,47
27645 INC E Move DE along to the next slot in the buffer
Compute and insert the 100s digit.
27646 INC A Get the ASCII code for the 100s digit in A
27647 ADD HL,BC
27648 JR C,27646
27650 SBC HL,BC
27652 LD (DE),A Place the 100s digit into the buffer
27653 LD C,246 BC=-10
27655 LD A,47
27657 INC E Move DE along to the next slot in the buffer
Compute and insert the 10s digit.
27658 INC A Get the ASCII code for the 10s digit in A
27659 ADD HL,BC
27660 JR C,27658
27662 SBC HL,BC
27664 LD (DE),A Place the 10s digit into the buffer
27665 INC E Move DE along to the next slot in the buffer
Compute and insert the units digit.
27666 LD A,L A=number of units left
27667 ADD A,48 A=ASCII code for the units digit
27669 LD (DE),A Place this into the buffer
27670 RET
Prev: 27570 Up: Map Next: 27671