Basic DOS-based speed compensation

Mo'Slo version 1.5.1 is the latest update to the original Mo'Slo released in 1990, now enhanced with 2 slowdown methods and 0.01% slowdown increment. Mo'Slo version 1.5 has the slowdown engine of Mo'Slo Deluxe version 3.2, but lacks the APIC slowdown method, cache disabling, processor emulations, slowdown of batch files, keyboard speed adjustment, and passing of parameters to slowed programs. Its DOS-based slowdown is less effective under Windows 95, 98 and ME, and does not consistently overcome load-time divide errors under Windows NT/2K/XP/Vista, where Mo'Slo 4BIZ is often required. While slowing a program, Mo'Slo version 1.5.1 uses only 674 bytes of memory plus the size of the DOS environment block.

Mo'Slo version 1.5 runs on Intel-compatible 32-bit processors 80386 and newer, plus AMD Athlon 64 and Opteron. It also runs in DOS and Windows emulators on other platforms. The 1.5.1 update overcomes a memory allocation problem with FreeDOS.

Mo'Slo version 1.5 can be freely downloaded and used subject to the terms of the Evaluation License below. The installation program is compatible with both DOS and Windows. After you agree to the terms of the Evaluation License, the installation program copies two files onto your system: the Mo'Slo program (MOSLO.COM) and the User Guide (MOSLO15.TXT). You can view the User Guide from the installation program, but to print it you will need to open it in Edit (DOS) or Notepad (Windows). 15 days after installation, a licensing plea will display and a key press will be required to begin slowdown.

When Mo'Slo basic is licensed for continued use, the licensing plea is replaced with a splash screen that displays the licensee name and number of seats licensed.

Please read the Evaluation License before downloading.


The Mo'Slo version 1.5 software program (the Software) is owned by David Perrell (the Author) and is protected by United States copyright laws and related international treaty provisions. You are licensed by the Author to use and distribute the Software subject to the following terms and conditions:

  1. You may use the Software without charge for a period of 15 days to evaluate its fitness for your needs. If the Software fulfills your needs, or if you wish to continue to use the Software for more than 15 days, you must purchase an End User License UNLESS your ONLY use of the Software is for your personal recreation NOT associated with any commercial or government enterprise, in which case you may continue to use the Software without charge.
  2. You may freely distribute the Software ONLY in the form of the Author-written installer program titled "Mo'Slo Eval Installer," which displays this license prior to installing the Software and User Guide. No compensation may be accepted for distribution of the Software. The Software may not be sold, traded, bundled with other goods or services, or used for promotional purposes without prior written permission from the Author.
  3. You may not make or have made any modification to the Software, User Guide, or installer program. You may not adapt, translate, reverse-engineer, disassemble, or create derivative works based on the Software.

Downloading implies agreement to abide by the above terms and conditions. If you do not agree to any of these terms or conditions, do not download, use, copy, or distribute the Software. The Author reserves the right to revoke the right to distribute the Software at any time.


Mo'Slo is provided without warranty of any kind, express or implied, and the user assumes the entire risk of using it. The Author will not be liable for any incidental, consequential, indirect or similar damages resulting from the use of this software. In no event will the Author's liability ever exceed the price paid for the license to use the software, regardless of the nature of the claim.

If you agree to the terms and conditions of the Evaluation License, you can download Mo'Slo v1.5.1 as an executable Installer Program (moslo15.exe, 26,282 bytes) or as the Installer Program in a ZIP archive (, 11,659 bytes).

NOTE: If you install in Windows XP or Vista you may see a warning window stating that “The publisher could not be verified” and asking “Are you sure you want to run this software?” The warning is displayed because we are a small company and cannot afford to pay a substantial yearly fee to Verisign for digital signatures to ‘identify’ our software. Please understand that by downloading our software from our website you are getting more proof that this is our software than you would get from a digital signature.

Trademarks and registered trademarks are property of their respective owners.
Dr.David's Super Crispy Software division of Hearn/Perrell Art Associates.
© Copyright Hearn/Perrell Art Associates, 2015.
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