2 Games

This program packages two games in one: a Rock-Scissors-Paper game played over 10 rounds against the computer, and a keyboard-location tutor that tests the player’s ability to find keys on a QWERTY layout. The Rock-Scissors-Paper game uses INK coloring and FLASH attributes to highlight results, tracking scores for both the player and the computer across rounds. The keyboard tutor stores each key’s character and screen position as a five-character string in a 36-element string array, encoding row and column coordinates directly in the data so a single AT expression can position the flashing letter on screen. A central menu at line 2000 uses POKE 23658,8 to enable the INPUT statement to accept uppercase letters regardless of the keyboard shift state, then routes the player to the chosen game.

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Program Structure

The listing is organized into three logical blocks plus a shared menu:

• Lines 30–320 – Rock-Scissors-Paper game (10 rounds, score tracking)
• Lines 1000–1240 – Keyboard location tutor (10 questions, scored)
• Lines 2000–2040 – Main menu and dispatcher, entered on first run (via SAVE … LINE 2000) and returned to after each game ends

Both games jump to line 2000 when finished. The menu routes back to line 1 (which falls through to line 30, the first real executable line of the RSP game) for option R, or to line 1000 for option T.

Rock-Scissors-Paper Logic

The game runs a FOR a=1 TO 10 loop. The computer’s choice c is generated with INT(RND*3)+1. Win/loss detection at lines 240 and 250 uses compound AND/OR conditions to enumerate all winning combinations. A draw at line 230 and a computer win at line 240 both use GO TO d (where d=260) to skip the player-win check, avoiding double-counting; this is a compact substitute for ELSE.

There is a notable typo at line 230: "It,s a draw!" uses a comma instead of an apostrophe. Additionally, the apostrophe short-print idiom ('" producing a newline before the string) is used consistently throughout both games.

After the 10-round loop, lines 290–310 compare hum and comp with INVERSE 1 set at line 285, so the final result message is displayed in inverse video.

Keyboard Tutor Data Encoding

The tutor’s most interesting feature is its compact data format. Each entry in the 36×5 string array A$ encodes three pieces of information in a single five-character string:

Position	Content	Example (“A1202”)
A$(B,1) – char 1	The key character to display	A
A$(B)(2 TO 3) – chars 2–3	Screen row (for AT)	12 → row 12
A$(B)(4 TO 5) – chars 4–5	Screen column (for AT)	02 → col 2

Line 1120 extracts these fields with slice notation and wraps them in VAL() to convert the two-digit substrings to numeric AT coordinates, then prints the letter with FLASH 1; PAPER 6 at the correct keyboard-layout position on screen. This positions each character to visually approximate the QWERTY keyboard layout.

Tutor Control Flow Anomaly

The keyboard tutor has a significant structural bug in its inner loop. The response-detection loop runs at lines 1130–1150; when a keypress is detected (C$<>""), execution jumps to line 1250. However, line 1250 does not exist in the listing. Lines 1190–1210, which contain the scoring logic, are never reached by any code path — the GO TO 1250 statements at lines 1140, 1180, 1200, and 1100 all jump past them. As written, the tutor will always display “YOU TOOK TOO LONG” and never award points, making SCORE permanently zero.

Key BASIC Idioms and Techniques

• VAL "INT(RND*36)+1" at line 1110 — stores an expression as a string to reduce memory footprint, a recognized ZX Spectrum BASIC optimization.
• POKE 23658,8 at line 2010 — sets FLAGS2 to force uppercase input mode, so the INPUT statement accepts R or T without the user needing to hold CAPS SHIFT.
• LET d=260 / GO TO d at lines 220–230 — uses a variable as a branch target, equivalent to a computed GOTO, to share the skip-to-score-display logic between the draw and computer-win branches.
• Color attributes (INK, PAPER, FLASH, BRIGHT) are used inline within PRINT statements throughout, with the player’s choice number conveniently reused as an ink color index at line 120.
• DIM A$(36,5) — a two-dimensional string array used as a structured record store, with fixed-width fields acting as a simple flat-file database.