ConvRStr

;===============================================================
ConvRStr:
;===============================================================
;Input:
;     HL points to the base 10 number or the byte before
;Outputs:
;     A is the byte before the number
;     BC is the 16-bit value of the number
;     DE is 10^(number of digits plus one)
;     HL points to the byte after the number
;Size:  38 bytes
;Speed: 139d+11w+25[+12 if ending byte is >39h]
;       d is the number of digits in the number
;       w is at most the number of digits minus 2
;       at most 765 cycles
;===============================================================
        dec hl
        bit 3,(iy+34)
        jp nz,ConvHexStr
        ld bc,0
ConvLoop:
        ld a,(hl)
        sub 30h \ ret c
        cp 10 \ ret nc
        inc hl
        ld (progPtr),hl

        ld h,b \ ld l,c
        add hl,hl
        add hl,hl
        add hl,bc
        add hl,hl
        ld b,h

        add a,l
        ld hl,(progPtr)
        ld c,a
        jr nc,ConvLoop
        inc b
        jr ConvLoop