---
title: "Dice Game"
id: 57537
type: "computer_media"
slug: "dice-game"
url: "http://localhost/computer_media/dice-game/"
markdown_url: "http://localhost/computer_media/dice-game.md"
published_at: "2024-10-05T21:38:43+00:00"
modified_at: "2026-03-30T21:17:19+00:00"
author: "David Anderson"
featured_image:
  url: "http://localhost/wp-content/uploads/2024/10/292_DG.png"
excerpt: "A three-dice betting game where you wager your $30 stake, pick a number, and watch each die reveal itself with UDG graphics and inverse-video flair."
category:
  - name: "Archived Media"
    slug: "archived-media"
    taxonomy: "category"
    url: "http://localhost/category/archived-media/"
post_tag:
  - name: "Downloadable"
    slug: "downloadable"
    taxonomy: "post_tag"
    url: "http://localhost/tag/downloadable/"
  - name: "TS 1000"
    slug: "ts1000"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ts1000/"
model:
  - name: "Timex/Sinclair 1000"
    slug: "ts-1000"
    taxonomy: "model"
    url: "http://localhost/model/ts-1000/"
genre:
  - name: "Game"
    slug: "game"
    taxonomy: "genre"
    url: "http://localhost/type/game/"
media_contents:
  - id: 56737
    title: "Timex Sinclair Public Domain Library Tape 1006"
    type: "computer_media"
    url: "http://localhost/computer_media/timex-sinclair-public-domain-library-tape-1006/"
media_type: "Program"
mediadate: "198x"
images:
  - url: "http://localhost/wp-content/uploads/2024/10/292_DG.png"
media_type_tags: "Game, Software"
---

This program implements a simple dice-betting game in which the player starts with $30 and repeatedly wagers on the outcome of three virtual dice rolls. Each round, the player chooses a bet amount (capped at their current stake) and a target number from 1 to 6; three dice are then rolled sequentially using RND, and any die matching the chosen number pays out the bet amount. Display uses inverse-video characters (the %X escapes) for a highlighted “GAME OVER” message, and UDG characters (CHR$ (C+156) and CHR$ (D+156)) to render die face graphics for each roll. A short busy-loop at lines 290–310 serves as a delay routine between dice reveals. The program alternates between a normal and inverse-video version of the “GAME OVER” text in a tight loop to produce a flashing effect.

***

## Program Analysis

### Program Structure

The program is organized around a main game loop (lines 10–270) with two subroutines sharing a single `RETURN` at line 310. The flow is as follows:

1. Line 10: Initialize stake `M=30`
2. Lines 20–70: Display stake, accept and validate bet amount `A`
3. Lines 80–110: Accept and validate target number `B` (1–6)
4. Lines 120–210: Roll three dice in a `FOR` loop, display results, accumulate winnings
5. Lines 220–270: Pause, clear screen, check for bankruptcy or loop back
6. Lines 280–310: Two subroutines — stake display (line 280) and delay loop (line 290) — sharing one `RETURN`

### Subroutine Sharing

Lines 280–310 implement a dual-entry subroutine pattern. `GOSUB 280` prints the current stake and then falls through into the delay loop before returning. `GOSUB 290` skips the print and executes only the delay. This is a common Sinclair BASIC memory-saving idiom that avoids duplicating the `FOR…NEXT` delay code.

### Dice Rolling and UDG Display

Each die result `D` is generated at line 150 with `LET D=INT (RND*6)+1`, producing values 1–6. The display at line 160 uses `CHR$ (C+156)` and `CHR$ (D+156)` to reference UDG characters in the range 157–162, presumably pre-defined elsewhere (or loaded as part of the saved program) to depict die faces. The die index `C` (1–3) is used to position each result on a separate screen row via `AT 11+2*C,0`.

### Inverse-Video and Flash Effect

Line 160 uses the `%X` inverse-video escape to render the label text (“DIE”, “FELL”) in inverse. Lines 250 and 260 together create a flashing “GAME OVER” effect: line 250 prints the normal text and line 270 loops back to 250, while line 260 prints the same message in full inverse video. Because the `GOTO 250` at line 270 passes through line 260 each cycle, the display alternates between normal and inverse rendering, producing a visible flash.

### Win Condition and Stake Management

For each of the three dice, if `D=B` the player wins `A` dollars (line 170 sets `W=A`; line 190 adds `W` to `M`). If no die matches, `W` remains 0 from line 130 and nothing is added. The initial deduction of the bet occurs at line 70 (`LET M=M-A`) before the dice are rolled, so winnings are net additions on top of the already-reduced stake.

### Input Validation

- Bet size: Line 50 rejects bets larger than the current stake (`IF A>M THEN GOTO 40`), but does not guard against zero or negative bets.
- Number choice: Line 110 enforces `1 ≤ B ≤ 6` with `IF B<1 OR B>6 THEN GOTO 80`.

### Delay Routine

The delay subroutine at lines 290–310 is a simple busy-loop iterating 50 times with an empty `FOR N=1 TO 50 / NEXT N`. This provides a brief pause between dice reveals to create a sense of suspense. The loop count of 50 may feel very short on slower machines but was likely tuned for the target hardware speed.

### Save and Auto-Run

Lines 320–340 perform a `CLEAR`, `SAVE`, and `RUN` sequence. The filename `"1029%2"` contains an inverse-video character (`%2`), which encodes the auto-run flag in the tape header so the program starts automatically on load.

### Notable Anomalies

| Line | Issue |
| --- | --- |
| 130 | `LET W=0` is inside the `FOR C` loop, correctly resetting the win flag each die roll. |
| 250–270 | The alternating normal/inverse loop never terminates; there is no `STOP` or escape, so the player must perform a manual break. |
| 50 | No guard against `A≤0`; a bet of zero is accepted and results in no stake change per round. |

## Source Code

```
  10 LET M=30
  20 GOSUB 280
  30 PRINT AT 6,8;"SIZE OF BET ? ";
  40 INPUT A
  50 IF A>M THEN GOTO 40
  60 PRINT "$";A
  70 LET M=M-A
  80 PRINT AT 10,8;"NUMBER ? ";
  90 INPUT B
 100 PRINT B
 110 IF B<1 OR B>6 THEN GOTO 80
 120 FOR C=1 TO 3
 130 LET W=0
 140 GOSUB 290
 150 LET D=INT (RND*6)+1
 160 PRINT AT 11+2*C,0;"%D%I%E% ";CHR$ (C+156);"% %F%E%L%L% ";CHR$ (D+156)
 170 IF D=B THEN LET W=A
 180 IF D=B THEN PRINT ,"WIN $";W
 190 LET M=M+W
 200 GOSUB 280
 210 NEXT C
 220 GOSUB 290
 230 CLS 
 240 IF M>0 THEN GOTO 20
 250 PRINT AT 10,3;"GAME OVER, YOU ARE BROKE"
 260 PRINT AT 10,3;"%G%A%M%E% %O%V%E%R%,% %Y%O%U% %A%R%E% %B%R%O%K%E"
 270 GOTO 250
 280 PRINT AT 2,12;"STAKE $";M; "  "
 290 FOR N=1 TO 50
 300 NEXT N
 310 RETURN 
 320 CLEAR 
 330 SAVE "1029%2"
 340 RUN
```