;;==========================================================================;; ;; Useful Routines ;; ;; Copyright 1999-2002, Joe Zbiciak. ;; ;; ;; ;; This file contains a number of useful routines that you're welcome ;; ;; to use in your own software. Please keep in mind that these routines ;; ;; are licensed under the GNU General Public License, and so if you plan ;; ;; to distribute a program which incorporates these routines, it too must ;; ;; be distributed under the GNU General Public License. ;; ;;==========================================================================;; ;;==========================================================================;; ;; NOTE: THIS FILE CONTAINS DEC16 ROUTINES ONLY, AND HAS BEEN MODIFIED ;; ;; TO REMOVE SUPPORT FOR DEC32. IF YOU NEED DEC32, USE THE OTHER FILE ;; ;; NAMED "dec16dec32.asm". THANK YOU. ;; ;;==========================================================================;; ;; ======================================================================== ;; ;; GLOBAL VARIABLES USED BY THESE ROUTINES ;; ;; ;; ;; Note that some of these routines may use one or more global variables. ;; ;; If you use these routines, you will need to allocate the appropriate ;; ;; space in either 16-bit or 8-bit memory as appropriate. Each global ;; ;; variable is listed with the routines which use it and the required ;; ;; memory width. ;; ;; ;; ;; Example declarations for these routines are shown below, commented out. ;; ;; You should uncomment these and add them to your program to make use of ;; ;; the routine that needs them. Make sure to assign these variables to ;; ;; locations that aren't used for anything else. ;; ;; ======================================================================== ;; ; Used by Req'd Width Description ;----------------------------------------------------- ;DEC_0 EQU $110 ; DEC16 8-bit Temp. storage ;DEC_1 EQU $111 ; DEC16 8-bit Temp. storage ;; ======================================================================== ;; ;; POW10 ;; ;; Look-up table with powers of 10 as 32-bit numbers (little endian). ;; ;; ======================================================================== ;; POW10 PROC @@5 WORD 100000 AND $FFFF, 100000 SHR 16 ; 10**5 @@4 WORD 10000 AND $FFFF, 10000 SHR 16 ; 10**4 @@3 WORD 1000 AND $FFFF, 1000 SHR 16 ; 10**3 @@2 WORD 100 AND $FFFF, 100 SHR 16 ; 10**2 @@1 WORD 10 AND $FFFF, 10 SHR 16 ; 10**1 @@0 WORD 1 AND $FFFF, 1 SHR 16 ; 10**0 ENDP ;; ======================================================================== ;; ;; DEC16 ;; ;; Displays a 16-bit decimal number on the screen with leading blanks ;; ;; in a field up to 5 characters wide. Displays all blanks if the ;; ;; number is zero. ;; ;; ;; ;; DEC16A ;; ;; Same as DEC16, only displays leading zeroes. ;; ;; ;; ;; DEC16B ;; ;; Same as DEC16, only leading zeros are controlled by bit 15 of R3. ;; ;; (If set, suppress leading zeros. If clear, show leading zeros.) ;; ;; ;; ;; DEC16C ;; ;; Same as DEC16B, except R1 contains an amount to add to the first ;; ;; digit. ;; ;; ;; ;; DEC16Z ;; ;; Same as DEC16, except displays a single zero if the value is zero. ;; ;; ;; ;; INPUTS: ;; ;; R0 -- Number to be displayed in decimal. ;; ;; R1 -- (DEC16C only): Amount to add to initial digit. ;; ;; R2 -- Number of digits to suppress (If R2<=5, it is 5-field_width) ;; ;; R3 -- Color mask / screen format word (XORd with char index) ;; ;; R4 -- Screen offset (lower 8-bits) ;; ;; ;; ;; OUTPUTS: ;; ;; R0 -- Zeroed ;; ;; R1 -- Trashed ;; ;; R2 -- Remaining digits to suppress (0 if initially <= 5.) ;; ;; R3 -- Color mask, with bit 15 set if no digits displayed. ;; ;; R4 -- Pointer to character just right of string ;; ;; R5 -- Trashed ;; ;; ;; ;; NOTES: ;; ;; Routine uses DEC_0, DEC_1 for temporary storage. This routine ;; ;; is NOT REENTRANT, so be careful calling this routine from an ;; ;; an interrupt handler if you also call either from outside an ;; ;; interrupt handler as well. ;; ;; ;; ;; To make this code re-entrant, save the contents of DEC_0 and ;; ;; DEC_1 before calling any variant of DEC16 from within an interrupt ;; ;; handler and then restore DEC_0 and DEC_1 afterwards. ;; ;; ======================================================================== ;; DEC16 PROC @@so EQU DEC_0 @@fw EQU DEC_1 SETC ; Prepare to set bit 15 of color mask INCR R7 ; Skip the CLRC DEC16A CLRC ; Prepare to clear bit 15 of clrmask SLL R3, 1 RRC R3, 1 ; Set/clear bit 15 of color mask DEC16B CLRR R1 DEC16C PSHR R5 ; Save return address MOVR PC, R5 ; (generate PC-relative address) SUBI #$-POW10.4, R5 ; Point to '10000' entry in POW10 MVO R4, @@so ; Save screen offset MVO R2, @@fw ; Save field width MVII #5, R4 ; Iterate 5 (16-bit goes to 65536) MOVR R1, R2 INCR R7 @@digitlp: CLRR R2 ; Start with division result == 0 SDBD MVI@ R5, R1 ; Load power of 10 ADDI #2, R5 ; Point to next smaller power of 10 @@divloop: INCR R2 SUBR R1, R0 ; Divide by repeated subtraction BC @@divloop ADDR R1, R0 ; Loop iterates 1 extra time: Fix it. DECR R2 ; Fix extra iter. Also test if 0 BNEQ @@disp ; If digit != 0, display it. TSTR R3 ; If digit == 0 and no lead 0, skip BMI @@blank @@disp: SLL R3, 1 ; Clear "no leading 0" flag SLR R3, 1 ; MVI @@fw, R1 ; Get field width DECR R1 ; Are we in active field yet? BMI @@ok ; Yes: Go ahead and display MVO R1, @@fw ; No: Save our count-down till field B @@iter ; and don't display the digit. @@blank: MOVR R3, R2 ; Blank character _just_ gets format MVI @@fw, R1 ; Get field width DECR R1 ; Are we in active field yet? BMI @@drawit ; Yes: Go ahead and display MVO R1, @@fw ; No: Save our count-down till field B @@iter ; and don't display the digit. @@ok: ADDI #$10, R2 ; Pseudo-ASCII digits start at 0x10 SLL R2, 2 ; Put pseudo-ASCII char in position ADDR R2, R2 ; ... by shifting left 3 XORR R3, R2 ; Merge with display format @@drawit: MVI @@so, R1 ; Get screen offset XORI #$200, R1 ; Move to screen MVO@ R2, R1 ; Put character on screen INCR R1 ; Move the pointer MVO R1, @@so ; Save the new offset @@iter: DECR R4 ; Count down our digit count BNEQ @@digitlp ; Keep iterating MVI @@so, R4 ; Restore offset MVI @@fw, R2 ; Restore digit suppress ocunt PULR PC ; Whew! Done! ENDP ;; ======================================================================== ;; ;; DEC16Z ;; ;; Same as DEC16, except a zero is displayed in the final position if ;; ;; the whole number's value is zero. ;; ;; ;; ;; INPUTS: ;; ;; R0 -- Lower 16-bits of number ;; ;; R2 -- Number of leading digits to suppress ;; ;; (5 - field_width for DEC16Z). ;; ;; R3 -- Screen format word ;; ;; R4 -- Screen offset (lower 8-bits) ;; ;; ;; ;; OUTPUTS: ;; ;; R0 -- Zeroed ;; ;; R1 -- Trashed ;; ;; R2 -- If number == 0, unchanged. ;; ;; If number != 0, remaining digits to suppress. ;; ;; R3 -- Color mask, unmodified. ;; ;; R4 -- Pointer to character just right of string ;; ;; R5 -- Trashed ;; ;; ;; ;; NOTES: ;; ;; DEC16Z uses DEC_0..DEC_1 for temporary storage. ;; ;; DEC16 variants are not re-entrant. See DEC16 above for details. ;; ;; ======================================================================== ;; DEC16Z PROC TSTR R0 ; Is the number non-zero? BNEQ DEC16 ; Yes: Call DEC16 MVII #5, R1 ; No: Prepare to clear the field and draw 0. @@dozero: SUBR R2, R1 ; Is our field wide enough to display the 0? BLE @@nodisp ; No: Don't display it then. ADDI #$200, R4 ; Yes: Calculate our screen pointer. INCR R7 ; (skip first iteration of loop) @@loop: MVO@ R3, R4 ; Clear the leading digits. DECR R1 BNEQ @@loop XORI #$80, R3 ; Now display a zero. MVO@ R3, R4 XORI #$80, R3 ; Leave R3 unchanged. @@nodisp: JR R5 ; Return to the caller. ENDP ;* ======================================================================== *; ;* This program is free software; you can redistribute it and/or modify *; ;* it under the terms of the GNU General Public License as published by *; ;* the Free Software Foundation; either version 2 of the License, or *; ;* (at your option) any later version. *; ;* *; ;* This program is distributed in the hope that it will be useful, *; ;* but WITHOUT ANY WARRANTY; without even the implied warranty of *; ;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *; ;* General Public License for more details. *; ;* *; ;* You should have received a copy of the GNU General Public License *; ;* along with this program; if not, write to the Free Software *; ;* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. *; ;* ======================================================================== *; ;* Copyright (c) 1999-2002, Joseph Zbiciak *; ;* ======================================================================== *;