# Microsoft Sam: a portable C rebuild of the SAPI 5 engine

> Rebuilds the Windows XP SAPI 5 engine spttseng.dll for Microsoft Sam, Mike, and Mary as C99 that reads the original voice files. The README reports audio of the same length with every sample within ±1 LSB of the 16-bit engine.

- Type: Case study
- Targets: Binary
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-04
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/KamiKitsune420/ms-sam-mike-mary-decomp>
- Primary source: <https://github.com/KamiKitsune420/ms-sam-mike-mary-decomp/blob/cf1122c6a4b6ad86cb1272690305c71449a17966/README.md>
- Catalog page: <https://awesomerea.org/resources/ms-sam-mike-mary-case/>
- Record JSON: <https://awesomerea.org/resources/ms-sam-mike-mary-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/ms-sam-mike-mary-case/index.md)

## Requirements & limits

- **Prerequisites:** Needs a C99 compiler and your own Sam.spd, Mike.spd, or Mary.spd with the matching .sdf files, plus LTTS1033.LXA and r1033tts.LXA. The README says the voice data is not included.
- **Scope:** Sam, Mike, and Mary share one engine. The README also describes SAPI 4 voice effects rebuilt as an audio effect, and says the SAPI 4 voices themselves are not ported. It says the small tables in src/sam_abbrev_tab.h, src/sam_pos_rules.h, and src/sam_words_tab.h were transcribed from the engine.
- **Testing evidence:** The README says about 99.7% of samples match exactly and the rest differ by float rounding, and reports 21/21 corpus sentences, 104/104 number and date lines, 100/100 homograph sentences, and 180/180 paragraphs of Alice in Wonderland. tools/compare_corpus.py compares the C output with WAVs that the README says are not included.
- **License:** The README says MIT for the code and points at LICENSE. That file is the MIT License, copyright 2026 KamiKitsune420. Microsoft voice data is not included.

## Primary sources

1. <https://github.com/KamiKitsune420/ms-sam-mike-mary-decomp/blob/cf1122c6a4b6ad86cb1272690305c71449a17966/README.md>
2. <https://github.com/KamiKitsune420/ms-sam-mike-mary-decomp/blob/cf1122c6a4b6ad86cb1272690305c71449a17966/tools/compare_corpus.py>
3. <https://github.com/KamiKitsune420/ms-sam-mike-mary-decomp/blob/cf1122c6a4b6ad86cb1272690305c71449a17966/LICENSE>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.