Let the player repeat it

The Spectrum can show an order. To make a game, it must listen to the player and judge their response. A key that is still held from WATCH must not become an accidental answer, and an unrelated key must not count as a wrong panel.

Continue from Play the stored order. We’ll first test one choice without playback, then connect the two phases. Keep the drawing and cue routines and the quit block throughout.

Make room for the game controller

The short main program is getting crowded between the board and the renderer. Move its next job to line 1000. Line numbers name positions in a program; they do not require us to fill the gaps.

Replace 290 with 290 GO TO 1000. Delete 295, 300, 305, 310, 315, 320, 325 and 330. Add the blocks at 1000–1080, 1500–1590 and 1600–1630 shown here:

290 GO TO 1000
1000 PRINT AT 18,0;"Release the keys.              "
1010 PRINT AT 20,0;"1-4 choose. Hold q to quit."
1020 GO SUB 1600
1030 PRINT AT 18,0;"YOUR TURN                     "
1040 GO SUB 1500
1050 GO SUB 900
1060 GO SUB 1600
1070 PRINT AT 18,0;"You chose ";k$;"                   "
1080 STOP
1500 LET k$=INKEY$
1510 IF k$="" THEN GO TO 1500
1520 IF k$="q" THEN GO TO 1900
1530 IF k$<"1" THEN GO TO 1580
1540 IF k$>"4" THEN GO TO 1580
1550 LET p=VAL k$
1560 RETURN
1580 GO SUB 1600
1590 GO TO 1500
1600 LET a$=INKEY$
1610 IF a$="q" THEN GO TO 1900
1620 IF a$<>"" THEN GO TO 1600
1630 RETURN

The jump at 290 passes over the renderer and cue definitions. We still reach those routines with GO SUB when we need them. STOP at 1080 prevents the controller from falling into the input routine when its single-choice job is done. The existing s$="314" remains stored, but this first checkpoint does not use it yet.

The controller prints the controls, asks for released keys, then announces YOUR TURN. It calls 1500 to obtain a panel choice, 900 to echo its signal, and 1600 to wait for release before reporting the choice.

Capture once, then validate

The routine at 1500 begins with LET k$=INKEY$. k$ keeps one reading so all the following tests examine the same value. Reading again after a test would introduce a gap in which the player could release or change the key.

The decisions have a deliberate order:

< and > compare the one-character strings in the Spectrum’s character order. The four digit characters are consecutive, so this range admits exactly our four identifiers. Use one choice key at a time: INKEY$ is not a general record of all simultaneously held keys.

Only after those checks does VAL k$ supply the numeric p. Trying to convert an empty reading, q or arbitrary text would give conversion a job it cannot do: deciding whether the player made a permitted choice.

RETURN at 1560 goes back to the caller with k$ and p available. This is shared state, not a value written after RETURN. The call leaves s$ alone.

A held key is still one press

The routine at 1600 captures into a different string, a$. It keeps reading while that value is not empty, with a q check so the player can leave even while waiting. <> means “not equal”.

Why not reuse k$ here? The controller still needs the accepted choice after the key has been released. Overwriting it with each release reading would replace it with "" just before the caller tried to judge it.

Release waits occur when crossing into the player’s phase or after consuming a key. The empty-input branch goes straight back to 1500: it does not call a release wait before every attempt. Otherwise a new press arriving while idle could be mistaken for an old press to discard.

Run the checkpoint. Press x: nothing should be chosen. Press 2: panel 2 should signal, then the program should show You chose 2. Run again and hold 2. There should still be one cue; the result waits until you release it. Try q on another run.

This input is deliberately blocking. The world does not move while the player considers a choice, and there is no response deadline. The cue occupies BASIC while it draws and sounds. Wait for that cue to finish before pressing the next choice. A tap made during it is not queued for later. The program is built for deliberate memory responses, not typing ahead.

One press, one step explores the same distinction between a held state and a fresh action in a movement experiment.

10 BORDER 0
20 PAPER 0
30 INK 7
40 CLS
50 PRINT "BRIGHT SPARK"
100 LET lit=0
110 FOR p=1 TO 4
120 GO SUB 500
130 NEXT p
240 PRINT AT 2,7;"1"
250 PRINT AT 2,23;"2"
260 PRINT AT 11,7;"3"
270 PRINT AT 11,23;"4"
280 LET s$="314"
290 GO TO 1000
500 LET pr=3
510 LET pc=2
520 LET colour=2
530 LET inkcol=7
540 LET note=0
550 IF p=2 THEN LET pc=18
560 IF p=2 THEN LET colour=1
570 IF p=2 THEN LET note=4
580 IF p=3 THEN LET pr=12
590 IF p=3 THEN LET colour=4
600 IF p=3 THEN LET inkcol=0
610 IF p=3 THEN LET note=7
620 IF p=4 THEN LET pr=12
630 IF p=4 THEN LET pc=18
640 IF p=4 THEN LET colour=6
650 IF p=4 THEN LET inkcol=0
660 IF p=4 THEN LET note=12
670 PAPER colour
680 INK inkcol
690 BRIGHT lit
700 FOR r=pr TO pr+5
710 PRINT AT r,pc;"            "
720 NEXT r
770 IF lit=1 THEN PRINT AT pr+2,pc+5;"*"
780 PAPER 0
790 INK 7
800 BRIGHT 0
810 RETURN
900 LET lit=1
910 GO SUB 500
920 BEEP 0.15,note
930 LET lit=0
940 GO SUB 500
950 PAUSE 10
960 RETURN
1000 PRINT AT 18,0;"Release the keys.              "
1010 PRINT AT 20,0;"1-4 choose. Hold q to quit."
1020 GO SUB 1600
1030 PRINT AT 18,0;"YOUR TURN                     "
1040 GO SUB 1500
1050 GO SUB 900
1060 GO SUB 1600
1070 PRINT AT 18,0;"You chose ";k$;"                   "
1080 STOP
1500 LET k$=INKEY$
1510 IF k$="" THEN GO TO 1500
1520 IF k$="q" THEN GO TO 1900
1530 IF k$<"1" THEN GO TO 1580
1540 IF k$>"4" THEN GO TO 1580
1550 LET p=VAL k$
1560 RETURN
1580 GO SUB 1600
1590 GO TO 1500
1600 LET a$=INKEY$
1610 IF a$="q" THEN GO TO 1900
1620 IF a$<>"" THEN GO TO 1600
1630 RETURN
1900 PRINT AT 18,0;"Finished. RUN to try again.     "
1910 PRINT AT 21,0;"                               "
1920 STOP

Connect WATCH, input and judgement

Replace the whole controller at 1000–1080 with the longer controller below, adding its new lines through 1170. Also add 275 for the controls and 1800–1820 for a mismatch. No other lines are deleted or changed.

275 PRINT AT 20,0;"1-4 choose. Hold q to quit."
1000 PRINT AT 18,0;"WATCH                         "
1010 FOR i=1 TO LEN s$
1020 IF INKEY$="q" THEN GO TO 1900
1030 LET p=VAL s$(i)
1040 GO SUB 900
1050 NEXT i
1060 IF INKEY$="q" THEN GO TO 1900
1070 PRINT AT 18,0;"Release the keys.              "
1080 GO SUB 1600
1090 PRINT AT 18,0;"YOUR TURN                     "
1100 FOR i=1 TO LEN s$
1110 GO SUB 1500
1120 GO SUB 900
1130 GO SUB 1600
1140 IF k$<>s$(i) THEN GO TO 1800
1150 NEXT i
1160 PRINT AT 18,0;"Order complete.               "
1170 STOP
1800 PRINT AT 18,0;"Different choice.             "
1810 BEEP 0.1,-12
1820 STOP

Lines 1000–1060 reproduce the playback loop in its new home. i visits each position, p receives the converted digit, and the cue returns before NEXT i. The q tests still surround the cues.

After WATCH, line 1070 announces the release wait. Line 1080 drains any held playback key, and only then does line 1090 show YOUR TURN. A player who presses 2 early cannot have it silently accepted as their first answer.

The second FOR i starts again at position 1. For each item it obtains a fresh valid choice, echoes the selected panel, and waits for release. Line 1140 then compares text with text: the accepted k$ against the expected s$(i). There is no need to convert either side of that comparison.

A mismatch jumps to 1800 immediately. The controller prints Different choice. and gives a short low note. A correct item reaches NEXT i. Only completing all those visits reaches Order complete. at 1160.

The lower failure note is BEEP 0.1,-12: a tenth of a second, one octave below pitch 0. Keep this cue brief; it marks the outcome without making a mistake unpleasant to hear. The text also communicates the result when sound is off.

Run and repeat 3, 1, 4. Then try a wrong first, middle and final choice on separate runs. Each should stop at Different choice.; later choices are no longer requested. If a correct choice fails, check that the release routine uses a$, leaving k$ intact.

For a repeated-key check, temporarily set line 280 to s$="22". Hold 2 during WATCH: the program should ask for release before YOUR TURN. Release it, then press and hold 2 again. One echoed cue should appear, but holding cannot finish the order. Release and make a second fresh press after the cue has finished. Only that second choice completes it. Restore s$="314" afterwards.

The status strings include trailing spaces to erase the previous message. They share row 18; the controls occupy row 20, away from the panel labels. If fragments of Release the keys. remain beside YOUR TURN, check those spaces rather than adding a CLS that would erase the board.

10 BORDER 0
20 PAPER 0
30 INK 7
40 CLS
50 PRINT "BRIGHT SPARK"
100 LET lit=0
110 FOR p=1 TO 4
120 GO SUB 500
130 NEXT p
240 PRINT AT 2,7;"1"
250 PRINT AT 2,23;"2"
260 PRINT AT 11,7;"3"
270 PRINT AT 11,23;"4"
275 PRINT AT 20,0;"1-4 choose. Hold q to quit."
280 LET s$="314"
290 GO TO 1000
500 LET pr=3
510 LET pc=2
520 LET colour=2
530 LET inkcol=7
540 LET note=0
550 IF p=2 THEN LET pc=18
560 IF p=2 THEN LET colour=1
570 IF p=2 THEN LET note=4
580 IF p=3 THEN LET pr=12
590 IF p=3 THEN LET colour=4
600 IF p=3 THEN LET inkcol=0
610 IF p=3 THEN LET note=7
620 IF p=4 THEN LET pr=12
630 IF p=4 THEN LET pc=18
640 IF p=4 THEN LET colour=6
650 IF p=4 THEN LET inkcol=0
660 IF p=4 THEN LET note=12
670 PAPER colour
680 INK inkcol
690 BRIGHT lit
700 FOR r=pr TO pr+5
710 PRINT AT r,pc;"            "
720 NEXT r
770 IF lit=1 THEN PRINT AT pr+2,pc+5;"*"
780 PAPER 0
790 INK 7
800 BRIGHT 0
810 RETURN
900 LET lit=1
910 GO SUB 500
920 BEEP 0.15,note
930 LET lit=0
940 GO SUB 500
950 PAUSE 10
960 RETURN
1000 PRINT AT 18,0;"WATCH                         "
1010 FOR i=1 TO LEN s$
1020 IF INKEY$="q" THEN GO TO 1900
1030 LET p=VAL s$(i)
1040 GO SUB 900
1050 NEXT i
1060 IF INKEY$="q" THEN GO TO 1900
1070 PRINT AT 18,0;"Release the keys.              "
1080 GO SUB 1600
1090 PRINT AT 18,0;"YOUR TURN                     "
1100 FOR i=1 TO LEN s$
1110 GO SUB 1500
1120 GO SUB 900
1130 GO SUB 1600
1140 IF k$<>s$(i) THEN GO TO 1800
1150 NEXT i
1160 PRINT AT 18,0;"Order complete.               "
1170 STOP
1500 LET k$=INKEY$
1510 IF k$="" THEN GO TO 1500
1520 IF k$="q" THEN GO TO 1900
1530 IF k$<"1" THEN GO TO 1580
1540 IF k$>"4" THEN GO TO 1580
1550 LET p=VAL k$
1560 RETURN
1580 GO SUB 1600
1590 GO TO 1500
1600 LET a$=INKEY$
1610 IF a$="q" THEN GO TO 1900
1620 IF a$<>"" THEN GO TO 1600
1630 RETURN
1800 PRINT AT 18,0;"Different choice.             "
1810 BEEP 0.1,-12
1820 STOP
1900 PRINT AT 18,0;"Finished. RUN to try again.     "
1910 PRINT AT 21,0;"                               "
1920 STOP

Save this as spark. It is now a playable fixed-order memory game: WATCH, repeat, then receive a result. Next we’ll give each game a new beginning and extend the order only after a whole round succeeds.