projects / avrcpm.git / blame
| Commit | Line | Data |
|---|---|---|
| 06644909 L |
1 | ; This is a utility program to control the timer of the AVR CP/M emulator. |
| 2 | ; This file is stolen from the SIMH AltairZ80 Simulator. | |
| 3 | ; | |
| 4 | ; changed to assemble with z80asm | |
| 5 | ; | |
| 6 | ; .Z80 ; mnemonics only | |
| 7 | ||
| 8 | ;SIMHPort equ 0feh | |
| 9 | TIMERCTL: equ 040h | |
| 10 | ||
| 11 | printStringCmd: equ 09h | |
| 12 | bdos: equ 5 | |
| 13 | cr: equ 13 | |
| 14 | lf: equ 10 | |
| 15 | cmdLine: equ 80h | |
| 16 | starttimercmd: equ 1 | |
| 17 | quitTimerCmd: equ 2 | |
| 18 | printTimerCmd: equ 15 | |
| 19 | uptimeCmd: equ 16 | |
| 20 | ||
| 21 | ; aseg | |
| 22 | org 100h | |
| 23 | ||
| 24 | jp start | |
| 25 | ||
| 26 | usage: db 'Usage: TIMER S|P|Q|U',cr,lf | |
| 27 | db ' S = (Re)Start the timer',cr,lf | |
| 28 | db ' P = Print elapsed time since last S or Q command',cr,lf | |
| 29 | db ' Q = Print the timer, then restart it',cr,lf | |
| 30 | db ' U = Print uptime',cr,lf,'$',1AH | |
| 31 | ||
| 32 | start: ld a,(cmdLine) ; get number of characters on command line | |
| 33 | or a | |
| 34 | jp z,pusage ; print usage, if command line empty | |
| 35 | ld a,(cmdLine+2) ; get first character | |
| 36 | ld hl,table ; <HL> points to (letter, command)^3 | |
| 37 | ld b,tabsize ; nr elements in table | |
| 38 | again: cp (hl) ; compare command line letter with table entry | |
| 39 | inc hl ; point to command | |
| 40 | jp z,found ; if found | |
| 41 | inc hl ; otherwise proceed to next entry | |
| 42 | dec b ; decrement loop counter | |
| 43 | jp nz,again ; try next character | |
| 44 | pusage: ld de,usage ; address of usage text | |
| 45 | ld c,printStringCmd ; CP/M command for print | |
| 46 | jp bdos ; print it, get ret from bdos | |
| 47 | found: ld a,(hl) ; get SIMH command | |
| 48 | out (TIMERCTL),a ; send to SIMH port | |
| 49 | ret ; and done | |
| 50 | ||
| 51 | table: db 'S',starttimercmd | |
| 52 | db 'P',printTimerCmd | |
| 53 | db 'Q',quitTimerCmd | |
| 54 | db 'U',uptimeCmd | |
| 55 | tabsize: equ ($-table)/2 | |
| 56 | ||
| 57 | timend: equ $ | |
| 58 | ds 0200h-timend ; fill remainder with zeroes | |
| 59 | ||
| 60 | end | |
| 61 | ||
| 62 | ; vim:set ts=8 noet nowrap | |
| 63 |