Routines
Prev: 29230 Up: Map Next: 29323
29257: Input: Wait For A Key
Used by the routine at ReadTheInputLine.
Counts down the input delay while polling the keyboard. A key raises the next delay by 500, up to 3000, and is returned. If the delay runs out, 29329 is printed into the buffer, ENTER is returned, and the next delay is cleared.
Input_WaitForAKey 29257 PUSH HL Read the input delay.
29258 LD HL,(46868)
Input_WaitForAKey_Poll 29261 CALL GetKey Poll the keyboard.
29264 AND A Jump to Input_WaitForAKey_AddToTheDelay if a key is waiting.
29265 JR NZ,Input_WaitForAKey_AddToTheDelay
29267 DEC HL Loop back to Input_WaitForAKey_Poll to keep polling until the delay runs out.
29268 LD A,H
29269 OR L
29270 JR NZ,Input_WaitForAKey_Poll
29272 POP HL Rub out the characters typed so far.
29273 PUSH HL
29274 CALL Input_RubOutCharacters
29277 LD DE,29329 Point at the letters W, A, I, T.
29280 LD B,4 Four letters.
Input_WaitForAKey_Wait 29282 LD A,(DE) Store the next letter of 29329 in the input buffer.
29283 LD (HL),A
29284 INC HL
29285 INC DE
29286 CALL Print_Character Print that letter.
29289 DJNZ Input_WaitForAKey_Wait Loop back to Input_WaitForAKey_Wait until 29329 is done.
29291 EX (SP),HL Remember the pointer after 29329, and prepare ENTER. The next delay is 65036 plus 500, which is zero.
29292 LD B,124
29294 LD A,13
29296 LD HL,65036
Input_WaitForAKey_AddToTheDelay 29299 PUSH AF Add 500 to the delay. A key raises the current delay; the timeout path adds it to zero.
29300 XOR A
29301 LD DE,500
29304 ADC HL,DE
29306 LD DE,3000 The cap is 3000.
29309 JR C,Input_WaitForAKey_Cap Jump to Input_WaitForAKey_Cap if the sum overflowed, and use the cap.
29311 CALL Input_CompareTwoTotals Call Input_CompareTwoTotals to compare the delay with the cap.
29314 JR C,Input_WaitForAKey_Store Jump to Input_WaitForAKey_Store if the delay is still under the cap.
Input_WaitForAKey_Cap 29316 EX DE,HL Use the cap instead.
Input_WaitForAKey_Store 29317 LD (46868),HL Store the next input delay.
29320 POP AF Restore AF and HL from the stack.
29321 POP HL
29322 RET Return.
Prev: 29230 Up: Map Next: 29323