This document describes Release 1.0 of a software package developed to aid the testing of software write block tools typically used in forensic investigations. The package includes programs that monitor the interrupt 13h BIOS disk interface and send selected commands to a software write block tool under test. The software is written in either Borland C++ 4.5 or Borland Assembler. The software can be used in the DOS environment to test an interrupt 0x13 based write block tool, measure the results and aid in documenting test runs. The intended audience for this document should be familiar with the DOS operating system, computer operation, computer hardware components such as hard drives, hard drive interfaces (e.g., IDE or SCSI) and computer forensics. A working knowledge of C and Assembly programming is not necessary for understanding but would be helpful.