The TRS-80 computer manufacturered by Tandy / Radio Shack contains an 8-bit character set.[1] It is partially derived from ASCII, and shares the code points from 32 - 95 on the standard model. Code points 96 - 127 are supported on models that have been fitted with a lower-case upgrade.[2]

The character set consists of letters, various numeric and special characters[1] as well as 64 semigraphics called squots (square dots) from a 2×3 matrix.[3] These were located at code points 128 to 191 with bits 5-0 following their binary representation,[3] similar to alpha-mosaic characters in World System Teletext.[4][5] These characters were used for graphics in games, such as Android Nim.[6]

Character set

The following table shows the TRS-80 model I character set. Each character is shown with a potential Unicode equivalent. Space and control characters are represented by the abbreviations for their names.

TRS-80 model I character set[7][3][8][9]
0 1 2 3 4 5 6 7 8 9 A B C D E F
0x BS[a] LF CR con[b] coff[c]
1x カ[d] 32[e] ←[f] →[g] ↓[h] ↑[i] home[j] sol[k] ceol[l] ceof[m]
2x  SP  ! " # $ % & ' ( ) * + , - . /
3x 0 1 2 3 4 5 6 7 8 9 : ; < = > ?
4x @ A B C D E F G H I J K L M N O
5x P Q R S T U V W X Y Z ↑ ↓ ← → _
6x a b c d e f g h i j k l m n o
7x p q r s t u v w x y z { | } ~ ±
8x NBSP
9x
Ax
Bx
Cx [n] tab tab tab tab tab tab tab tab tab tab tab tab tab tab tab
Dx tab tab tab tab tab tab tab tab tab tab tab tab tab tab tab tab
Ex tab tab tab tab tab tab tab tab tab tab tab tab tab tab tab tab
Fx tab tab tab tab tab tab tab tab tab tab tab tab tab tab tab tab
  1. ^ Backspace and erase current character
  2. ^ Cursor on
  3. ^ Cursor off
  4. ^ Toggles Katakana characters (Model III)
  5. ^ Converts to wide 32 column mode
  6. ^ Backspace ← Cursor
  7. ^ Advance → Cursor
  8. ^ Downward ↓ linefeed
  9. ^ Upward ↑ linefeed
  10. ^ Move cursor to (0,0), also turns off 32 column mode
  11. ^ Move to start of line
  12. ^ Erase to end of line
  13. ^ Erase to end of frame
  14. ^ 192 to 255 are "Space Compression Codes", tabs for 0 to 63 spaces

References

Citations

  1. ^ a b Fylstra, Dan (April 1978). "Radio Shack TRS-80: An Owner's Report" (PDF). BYTE. Boston, MA, USA: BYTE Publications Inc.: 49–59. Archived (PDF) from the original on 2017-07-29. Retrieved 2017-07-29.
  2. ^ Heiserman 1983, p. 15.
  3. ^ a b c Goldklang, Ira (2015). "Graphic Tips & Tricks". Archived from the original on 2017-07-29. Retrieved 2017-07-29.
  4. ^ Wiels. "TeleText - Het Protocol" (in Dutch). Mosaic characters. Archived from the original on 2017-12-22. Retrieved 2017-12-21.
  5. ^ https://www.etsi.org/deliver/etsi_i_ets/300700_300799/300706/01_60/ets_300706e01p.pdf#page=126[bare URL PDF]
  6. ^ Crawford 2003, p. 202.
  7. ^ Level II Basic Manual. Tandy / Radio Shack. 1978. pp. C1/C2.
  8. ^ "TRSM1ICH.TXT" (PDF), L2/19-025: Proposal to add characters from legacy computers and teletext to the UCS, 2019-01-04
  9. ^ Heiserman 1983, p. 243.

Sources

Further reading

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