---
title: "Keyboard Tutor"
id: 64745
type: "computer_media"
slug: "keyboard-tutor"
url: "http://localhost/computer_media/keyboard-tutor/"
markdown_url: "http://localhost/computer_media/keyboard-tutor.md"
published_at: "2026-03-07T14:45:25+00:00"
modified_at: "2026-03-30T21:43:24+00:00"
author: "David Anderson"
featured_image:
  url: "http://localhost/wp-content/uploads/2026/03/tutor.png"
excerpt: "A typing tutor that draws a UDG keyboard on screen, scores your keystrokes in real time, and reports accuracy as a percentage."
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 2068"
    slug: "ts2068"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ts2068/"
model:
  - name: "Timex/Sinclair 2068"
    slug: "ts-2068"
    taxonomy: "model"
    url: "http://localhost/model/ts-2068/"
genre:
  - name: "Education"
    slug: "education"
    taxonomy: "genre"
    url: "http://localhost/type/education/"
media_contents:
  - id: 64715
    title: "Miscellaneous Programs"
    type: "computer_media"
    url: "http://localhost/computer_media/miscellaneous-programs/"
media_type: "Program"
mediadate: "198x"
images:
  - url: "http://localhost/wp-content/uploads/2026/03/tutor.png"
media_type_tags: "Education"
---

# Keyboard Tutor

This program is a typing tutor that displays an on-screen keyboard graphic built from user-defined graphics (UDGs) and tests the user’s typing accuracy against a fixed set of practice phrases. Eight UDG characters (a–h) are defined at startup by poking 64 bytes read from DATA statements, forming a decorative keyboard border rendered with block-graphic characters. The program cycles through DATA phrases (lines 260–280), highlights correct keystrokes in BRIGHT and marks errors with a PAPER 5 flash, then computes and displays a running accuracy percentage. At the end of a session the user is prompted to continue or stop; the program can be saved with autostart at line 9 (which does not exist, so it will autostart at line 10).

***

## Program Structure

The program is organised into three logical phases:

1. **Initialisation (lines 10, 190–250):** Sets ink/paper colours, dimensions a dummy string array, calls the UDG-setup subroutine, and returns with the keyboard banner string stored in `P$`.
2. **Display (lines 20–60):** Draws the decorative keyboard graphic using `P$` and UDG sequences, then overlays alphabetic key labels with `PRINT OVER`.
3. **Typing-test loop (lines 70–180):** Reads a phrase from DATA, displays it, iterates character-by-character waiting for correct keystrokes, accumulates totals, prints accuracy, and prompts for another round.

## UDG Setup

The subroutine at line 190 reads 64 bytes from the DATA statements (lines 210–240) and POKEs them into the UDG area starting at `USR "a"`, defining eight custom characters `\a`–`\h`. These form the corners and edges of the on-screen keyboard frame. The assembled keyboard banner string is stored in `P$` and reused across three `PRINT` calls in line 20 to draw a three-row header.

## Key Variables

| Variable | Role |
| --- | --- |
| `O0` | Always 0 (`NOT PI` = 0); used as a readable zero literal throughout |
| `P$` | Pre-built UDG keyboard banner string (one row) |
| `TOT` | Total keystrokes attempted |
| `RI` | Correct (“right”) keystrokes |
| `A$` | Current practice phrase read from DATA |
| `T$` | Key currently pressed via `INKEY$` |
| `O$` | A 32-space string used to clear the display line before printing a phrase |

## Notable BASIC Idioms

- `NOT PI` evaluates to 0 (since PI is non-zero), assigned to `O0` and used wherever 0 is needed, saving a few bytes over the literal `0`.
- `SGN PI` evaluates to 1 and is used for ink colour 1 (blue) and loop start values, again saving bytes.
- `INT PI` evaluates to 3 and is used as a column offset in line 50.
- The keyboard-input loop (lines 110–120) is a busy-wait on `INKEY$`; `PAUSE 0` is not used here, so the CPU spins.
- Line 90 uses `TAB O0` (i.e. `TAB 0`) after printing the phrase to reset the print position to column 0 ready for character-by-character overlay.

## Typing Test Logic

For each phrase, the program erases the line using two 32-character blank strings (`O$;O$`), reprints the phrase in dim ink, then re-reads it one character at a time. Each keypress is compared against `A$(I)`; a wrong key is echoed in `PAPER 5` (cyan background), then immediately erased with `CHR$ 8` (backspace), and the loop retries. A correct key is printed `BRIGHT 1`. Every keypress — correct or not — increments `TOT`, while only correct ones increment `RI`; accuracy is `INT(RI/TOT*100)`.

## DATA Organisation and Sentinel

Practice phrases occupy lines 260–280 and are terminated by the sentinel string `"STOP"`. When the READ in line 80 encounters `"STOP"`, a `RESTORE 260` rewinds the DATA pointer to the phrases and immediately reads the first one again, creating a seamless loop. The UDG byte data (lines 210–240) is read only once during initialisation via a separate `RESTORE` (line 200 issues `RESTORE` with no argument, rewinding to line 210).

## Source Code

```
   10 LET O0=NOT PI: INK O0: PAPER 6: CLS : DIM O$(32): GO SUB 190
   20 CLS : PRINT P$'" ";P$'"  ";P$
   30 PRINT "\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\d \e\d \e\d \e\d \e\d \e\d \e\d \e\d \e\d \e\d \e\d \f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g"
   40 PRINT OVER SGN PI;AT SGN PI,O0;" 1  2  3  4  5  6  7  8  9  0";AT 4,2;"Q  W  E  R  T  Y  U  I  O  P"
   50 PRINT OVER SGN PI;AT 7,INT PI;"A  S  D  F  G  H  J  K  L  E";AT 10,1;"C  Z  X  C  V  B  N  M  S  B  C"
   60 PRINT AT 12,6;"\a\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\c           \d    SPACE  BAR     \e           \f\g\g\g\g\g\g\g\g\g\g\g\g\g\g\g\g\g\g\g\h"
   70 LET TOT=O0: LET RI=O0
   80 READ A$: IF A$="STOP" THEN RESTORE 260: READ A$
   90 PRINT INK SGN PI;AT 16,O0;O$;O$;AT 16,O0;A$;TAB O0;
  100 FOR I=SGN PI TO LEN A$
  110 LET T$=INKEY$: IF T$<>"" THEN GO TO 130
  120 GO TO 110
  130 LET TOT=TOT+1: BEEP .15,30: IF T$<>A$(I) THEN PRINT PAPER 5;T$;CHR$ 8;: GO TO 110
  140 LET RI=RI+1
  150 PRINT BRIGHT 1;T$;
  160 NEXT I: PRINT AT 21,25;INT (RI/TOT*100);"%  "
  170 INPUT "MORE? (Y/N) ";Q$: IF Q$<>"N" THEN PAUSE 25: GO TO 80
  180 STOP 
  190 REM USR charactors
  200 RESTORE : FOR i=O0 TO 63: READ byte: POKE USR "a"+i,byte: NEXT i: LET P$="\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c\a\b\c  \d \e\d \e\d \e\d \e\d \e\d \e\d \e\d \e\d \e\d \e  \f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h\f\g\h": RETURN 
  210 DATA O0,O0,O0,O0,O0,7,4,4,O0,O0,O0,O0,O0,255,O0,O0
  220 DATA O0,O0,O0,O0,O0,224,32,32,4,4,4,4,4,4,4,4
  230 DATA 32,32,32,32,32,32,32,32,4,4,7,O0,O0,O0,O0,O0
  240 DATA O0,O0,255,O0,O0,O0,O0,O0,32,32,224,O0,O0,O0,O0,O0
  250 RETURN 
  260 DATA "THIS IS A TS2068 TYPING TEST.","THE QUICK BROWN FOX JUMPED OVER"
  270 DATA "THE LAZY DOG.","JUST TYPE WHAT YOU SEE;"
  280 DATA "DO NOT LOOK AT THE KEYBOARD","STOP"
  290 SAVE "TUTOR" LINE 9
```