====== Human Interface ====== The Human Interface system routines handle input from the [[hardware:player input#keypad]] and [[hardware:player input#control handles]], scoring, system pausing and blackout, and menu display. ===== Human Interface System Routines ===== Undocumented routines are marked with an asterisk (*) ^ Name ^ Description ^ | [[human interface#doit|DOIT]] | Responds to input transition (and branches to transition handler) | | [[human interface#doitb|DOITB]]* | Like DOIT, but uses B instead of A | | [[human interface#getnum|GETNUM]] | Get a number from the user | | [[human interface#getpar|GETPAR]] | Get game parameter from user ("Enter ") | | [[human interface#incscr|INCSCR]] | Increment 3-byte score and compare to end score (ENDSCR) | | [[human interface#kctasc|KCTASC]] | Converts Bally keypad code to ASCII | | [[human interface#menu|MENU]] | Display menu and branch on choice | | [[human interface#msktd|MSKTD]] | Mask joystick in B to Deltas | | [[human interface#paws|PAWS]] | Pause for specified number of interrupts | | [[human interface#pizbrk|PIZBRK]] | Black out screen and wait for key/trigger/joystick input | | [[human interface#quit|QUIT]]* | Quit cartridge execution | | [[human interface#sentry|SENTRY]] | Wait for change of program status in ports/timers/counters | ===== Human Interface System Routine Descriptions ===== ==== DOIT ==== RESPOND TO INPUT TRANSITION | Calling Sequence: | SYSTEM DOIT or SYSSUK DOIT DW (DOIT table) | | Arguments: | A = Return code from [[#sentry|SENTRY]] routine\\ B = Extended return code\\ HL = DOIT table address | | Description: | This routine is used with [[#sentry|SENTRY]] for dispatching to a state transition routine. The return code from SENTRY is used to search the DOIT table. If a match is found, control is transferred to the associated handling routine. If no match is found, the routine repeats.\\ \\ The handling routine may be macro or machine instructions. The routine receives registers as they are on DOIT entry. If no transition is found, execution continues at the first instruction following call. | The DOIT table is a linear list composed of 3-byte entries, with one entry per SENTRY return code. {{:doit_table.png}} //Transfer type// (byte 0, bits 6–7) designates how the handler address is to be transferred to. The codes are: * 00 = JMP to machine language routine and pop context * 01 = [[upi#rcall|RCALL]] machine language routine in current context * 10 = [[upi#mcall|MCALL]] interpreter routine in current context Mode 01 and 10 expect the returned-to point to be interpretive; mode 00 expect it to be machine instructions. //Return code// (byte 0, bit 0–5) from [[#SENTRY]] routine (e.g., ST0, SJ1, SCT7, etc.) //Handler address// (bytes 1 and 2) contains the address of the handling routine. End of list is indicated by a terminator byte that is greater than or equal to $C0. ---- === Example: Football DOIT Table === ;********** ;* ;* Player Input Transition Table ;* ; DOTABLE: RC SCT7,DOCT7,0 ; CT7 RC ST0,DOTRIG0,0 ; TRIGGER 0 RC ST1,DOTRIG1,0 ; TRIGGER 1 RC SP0,DOKNOB0,0 ; Pot. 0 RC SP1,DOKNOB1,0 ; Pot. 1 RC SJ0,DOJOY0,0 ; Joystick 0 RC SJ2,DOJOY2,0 ; Joystick 2 RC SJ3,DOJOY3,0 ; Joystick 3 RC SJ1,DOJOY1,ENDx ; Joystick 1 Also see the [[human interface#keyboard input example|Keyboard Input Example]] below for example [[#SENTRY]] and DOIT usage. ==== DOITB ==== RESPOND TO INPUT TRANSITION (USING B) | Calling Sequence: | SYSTEM DOITB or SYSSUK DOITB DW (DOIT table) | | Notes: | Identical to DOIT, but uses B instead of A | ==== GETNUM ==== GET NUMBER | Calling Sequence: | SYSTEM GETNUM or SYSSUK GETNUM DB (x-coordinate) DB (y-coordinate) DB (CHRDIS options) DB (DISNUM options) DW (number address)| | Arguments: | B = [[screen handler#disnum|DISNUM]] display options\\ C = [[screen handler#chrdis|CHRDIS]] display options\\ D = Y-coordinate for feedback display\\ X-coordinate for feedback display\\ HL = Address to store entered number | | Description: | This routine captures number input from either the keypad or the player one control handle pot. Keypad entry has priority. The routine exits when the specified number of digits are entered or = is pressed on the keypad.\\ \\ Pot entry is enabled by pressing the trigger. The current pot value is then shown. Twist the pot until the number you want is shown, then press the trigger again to complete entry. | | Restrictions: | The pot can only enter 1 or 2 digits. If a group of numbers is being entered, the user must enable entry for each new number. | ==== GETPAR ==== GET GAME PARAMETER | Calling Sequence: | SYSTEM GETPAR or SYSSUK GETPAR DW (prompt) DB (digits) DW (parameter)| | Arguments: | A = number of digits to get\\ BC = address of prompt string\\ DE = title string address (not loaded)\\ HL = address of parameter to get | | Description: | A menu frame is created displaying the title passed in DE. The message "ENTER" is displayed in the center of the screen, followed by the prompt string. [[#getnum|GETNUM]] is entered with feedback specified in 2X enlarged characters. After entry is complete, GETPAR pauses for ¼ second to allow the user to see their entry, then returns. | | Notes: | See entry conditions and resource requirements for [[#menu|MENU]].\\ \\ Prompt string example: "# OF PLAYERS"\\ \\ The title string address (DE) is usually the title returned from [[#menu|MENU]].\\ \\ The parameter address (HL) points at the [[:glossary#l|low-order]] byte of the BCD number in RAM. | === Example === {{getpar_small.png}} A sample 2-digit GETPAR prompt from //[[:Gunfight]]//. ==== INCSCR ==== INCREMENT SCORE AND COMPARE TO END SCORE | Calling Sequence: | SYSTEM INCSCR or SYSSUK INCSCR DW (address of score)| | Arguments: | HL = Address of score (must be 3 bytes long) | | Output: | Score incremented and optionally game over bit set | | Description: | The 3-byte score pointed at by HL (BCD with low-order byte at lowest address) is incremented by 1 and compared to the end score (ENDSCR). If the end score bit (GSBSCR) was set in the game status byte (GAMSTB) and end score has been reached, then the game over bit (GSBEND) is set in the game status byte. | ==== KCTASC ==== KEY CODE TO ASCII | Calling Sequence: | SYSTEM KCTASC| | Arguments: | B = key code (not loaded) | | Output: | A = ASCII equivalent of key code | | Description: | This routine uses a lookup table (listed below) to return the proper ASCII code. | ^ Key Code ^ Name ^ Graphic ^ Hex Value ^ | 1 | Clear | C | 43 | | 2 | Up Arrow | ↑ | 5E | | 3 | Down Arrow | ↓ | 5C | | 4 | Percent | % | 25 | | 5 | Recall | MR | 52 | | 6 | Store | MS | 53 | | 7 | Change Sign | CH | 3B | | 8 | Divide | ÷ | 2F | | 9 | 7 | 7 | 37 | | 10 | 8 | 8 | 38 | | 11 | 9 | 9 | 39 | | 12 | Multiply | × | 2A | | 13 | 4 | 4 | 34 | | 14 | 5 | 5 | 35 | | 15 | 6 | 6 | 36 | | 16 | Minus | − | 2D | | 17 | 1 | 1 | 31 | | 18 | 2 | 2 | 32 | | 19 | 3 | 3 | 33 | | 20 | Plus | + | 2B | | 21 | Clear Entry | CE | 26 | | 22 | 0 | 0 | 30 | | 23 | Decimal Point | . | 2E | | 24 | Equals | = | 3D | ==== MENU ==== DISPLAY MENU AND BRANCH ON SELECTION | Calling Sequence: | SYSTEM MENU or SYSSUK MENU DW (menu title string address) DW (menu list address| | Arguments: | DE = Address of menu title string\\ HL = Address of menu list | | Output: | DE = String address of selection mode | | Description: | The title is displayed at the top of the screen. Each entry in the menu list is then displayed with a preceding number supplied by MENU. [[human interface#getnum|GETNUM]] is called to get the selection number. The menu list is searched for the selected node and it is jumped to. | | Notes: | A maximum of eight entries may appear.\\ \\ On entry, MENU expects [[hardware:interrupts]] to be enabled and colors and boundaries to be initialized. MENU uses 96 lines of screen, creams the alternate set, and requires three levels of context. MENU calls [[human interface#sentry|SENTRY]] and thus 'eats' all irrelevant transitions. | === MENU List Layout === {{:menu_list.png}} ==== MSKTD ==== CONVERT JOYSTICK MASK TO DELTAS | Calling Sequence: | SYSTEM MSKTD or LD B,(joystick mask) SYSSUK MSKTD DW (x-delta) DB (flop flag) DW (y-delta) | | Arguments: | B = Joystick mask (not loaded)\\ C = Flop flag\\ DE = X positive delta\\ HL = Y positive delta | | Output: | DE = X-Delta\\ HL = Y-Delta | | Description: | This routine uses the joystick mask and flop flag to conditionally modify the passed deltas. If negative direction is indicated, the delta is 2's complemented; if no direction is indicated, 0 is returned.\\ \\ MSKTD uses the value returned by a joystick and returns positive, negative, or zero values depending on the delta values provided. Delta values entered are what we would like to use if the joystick is held right (left if flopped) or down. Negative values will be returned if the joystick is left (right if flopped) or up.\\ \\ If we give it an x-delta of 1.0 for single pixel motion, we will get -1.0 for left, 0.0 for middle, and 1.0 for right. Dropping these values directly into the x-delta bytes of the vector block, then calling [[screen handler#VECT]] and [[screen handler#VWRITR]], will move the pattern appropriately for direct motion control. Passing a delta of 0.25 and adding the resulting values to the vector block deltas would simulate, for example, the inertial motion of a spaceship. | | Notes: | B is not loaded by SYSSUK.\\ \\ The joystick mask (B) is the byte value returned by the joystick port, either as a result of reading the appropriate [[hardware:i o ports|port]] for a joystick (e.g., $10 for joystick 0) or calling [[#SENTRY]] and picking up the joystick changes through [[#DOIT]] (which stores the mask in B). | ==== PAWS ==== PAUSE | Calling Sequence: | SYSTEM PAWS or SYSSUK PAWS DB (number of interrupts)| | Arguments: | B = number of interrupts to wait | | Description: | This routine pauses for a specified number of interrupts. If used with [[interrupt scheduler#actint|ACTINT]], a value of 60 = 1 second. This routine does an EI (enable interrupt) upon entry and assumes interrupts will occur. | ==== PIZBRK ==== BLACK OUT SCREEN AND WAIT FOR KEY | Calling Sequence: | SYSTEM PIZBRK or SYSSUK PIZBRK DB (number of interrupts)| | Arguments: | none | | Description: | This routine blacks out the screen and waits for either a key press, trigger, or joystick change. This function should be called whenever a "hold until further notice" is needed.\\ \\ All keys on the keypad are enabled. Interrupts are disabled on entry and enabled on exit. It is recommended to reset any 60th of a second timers on exiting PIZBRK. | | Note: | Often referred to as a 'coffee break' throughout the NM and other documentation. | ==== QUIT ==== QUIT CARTRIDGE EXECUTION | Calling Sequence: | SYSTEM QUIT | | Arguments: | None | | Description: | Displays the text 'GAME OVER' and holds the present game score until the system detects a key press or player 1 trigger pull. | ==== SENTRY ==== SENSE TRANSITION | Calling Sequence: | SYSTEM SENTRY or SYSSUK SENTRY DW (Key mask address)| | Arguments: | DE = Keypad mask table | | Output: | A = Return code\\ B = Extended code (see output chart below) | | Description: | SENTRY checks for changes in the potentiometers (pots), control handles, triggers, keypad, [[:glossary#s|semaphores]] (i.e., flags), and counters/timers. It also takes care of blackout, the automatic blacking-out of the screen after 255 seconds without a change. If SENTRY isn't called, then the game will not black out.\\ \\ SENTRY checks if TIMOUT equals zero on entry, and if zero, it goes to [[#PIZBRK]]. If a key has gone down or a control handle changed, then TIMOUT is set to $FF.\\ \\ HL should point at a keypad mask. The keypad consists of 6 rows by 4 columns.\\ \\ Example mask of 0–9 only:\\ DB 011100B DB 111100B DB 011100B DB 000000B | === Keypad Mask Layout === {{:keypad_mask.png}} === SENTRY Output Chart === ^ Priority ^ A = ^ Meaning ^ B = ^ | | SNUL | Return NULL (i.e., nothing happened) | | | 1 | SCT//n// | Counter/timer //n// decremented to 0 (//n// = 0–7) | | | 2 | SF//n// | SEMI4S (i.e., flag) bit //n// was 1 (//n// = 0–7) | | | 3 | SP//n// | Pot //n// changed (//n// = 0–3) | new value | | 4 | SSEC | 1 second has elapsed since the last SSEC | | | 5 | SKYU | Keypad went from down to up | 0 | | 5 | SKYD | Key is down | key number | | 6 | SJ//n// | Joystick //n// changed (//n// = 0–3) | new value | | 6 | ST//n// | Trigger //n// changed (//n// = 0–3) | new value | **Notes:** * The potentiometers (pots) are [[:glossary#d|debounced]]. * New trigger value = trigger off ($0) or trigger on ($10). * When switches are actuated simultaneously, the order of return is: SCT7 to SCT0, SF7 to SF0, SP0 to SP3, SSEC, SKYU, SKYD, SJ0, ST0, SJ1, ST1, SJ2, ST2, SJ3, ST3. ===== Keyboard Input Example ===== This routine echoes number keys and takes a coffee break (i.e., [[#pizbrk|PIZBRK]]) on trigger 0 being pulled. Assumes SP is set and screen erases. SYSTEM INTPC LOOP: DO SENTRY DW NUMBAS DO DOIT DW DTAB DO MJUMP DW LOOP NUMBAS: DB 011100B ;NUMBER KEYS ONLY DB 111100B DB 011100B DB 0 DTAB: MC SKYD,SHOW ;ON KEY DOWN MACRO CALL MC ST0,PBREAK+END ;ON TO MACRO CALL SHOW: DO KCTASC ;CONVERT TO ASCII DO SUCK DB 00000111B ;X,Y=0=DE DB 11001100B ;OPTIONS=C DONT CHRDIS ;DISPLAY CHAR MRET ;BACK TO LOOP PBREAK: DO PIZBRK ;COFFEE BREAK DO MRET ;BACK TO LOOP ---- [NM:55]