I created this document while working with my Smith Corona PWP 78 DS, a ‘Personal Word Processor’ typewriter capable of reading and writing files to a floppy drive. It uses a proprietary .pwp format to encode files so I wanted to understand it so I could create new documents with an external computer. This is what I was able to discover.
Header Format
1
2
3
4
?? ?? 20 20:20 20 20 20|20 20 20 20:20 4D 4C 34
44 20 27 39:32 01 00 FP|SP PS MT MB:ML ML MR MR
66 00 1A 01:00 00 00 00|00 00 00 00:00 00 00 00
00 00 00 00:00 00 00 00|00 00 00 00:00 00 00 00
| Code | Meaning | Values | Default |
|---|---|---|---|
?? | Size of file | 16-bit unsigned | |
FP | Pitch | 06 = 10 05 = 12 04 = 15 | 06 |
SP | Spacing | 02 = single 03 = 1.5 04 = double | 02 |
PS | Paper length | 42 = 11” 46 = A4 54 = 14” FC = No limit | 42 |
MT | Top margin | 06 | |
MB | Bottom margin | 06 | |
ML | Left margin | 16-bit unsigned | 48 00 |
MR | Right margin | 16-bit unsigned Limit is 52 02 | B0 01 |
Rows 3-4 are tabs in 2 byte sets
First two bits of second byte are tab type:
00 | Normal tab |
11 | Decimal tab |
10 | Tab center |
01 | Flush right |
Default tabs are 66 00 and 1A 01. All positions seem to be multiples of 6.
Special Characters
10 | New Line |
13 | Superscript |
14 | Subscript |
20 | Space |
0E | New Page |
Special Formatting
| Bold | 01 [A] 01 [B] 01 [C] |
| Underline | 02 [A] 02 [B] 02 [C] |
| Bold Underline | 03 [A] 03 [B] 03 [C] |
| Tab | 07 1E 1E 1E 1E 1E [ABC] |
| Center | 08 1E 1E .. .. 1E [ABC] 0D |
Supported Characters
21 | ! |
22 | ” |
23 | # |
24 | $ |
25 | % |
26 | & |
27 | ’ |
28 | ( |
29 | ) |
2A | * |
2B | + |
2C | , |
2D | - |
2E | . |
2F | / |
30 ↕ 39 | 0 ↕ 9 |
3A | : |
3B | ; |
3D | = |
3F | ? |
40 | @ |
41 ↕ 5A | A ↕ Z |
5B | [ |
5D | ] |
5E | ^ - Connects to next character |
5F | _ |
60 | ` - Connects to next character |
61 ↕ 7A | a ↕ z |
7E | ~ - Connects to next character |
82 | é |
87 | ç |
A8 | ¿ |
AB | ½ |
AC | ¼ |
BD | ¢ |
F4 | ¶ |
F5 | § |