MTK

This multitasker is purposely limited to simple mechanisms permitting a fast response to external events, efficient resource protection and quick context switching. Actual performance will vary with micro controller, due to varying suitability of instruction sets.
The multitasker has been implemented so that state diagrams can be coded almost directly. The WAIT syntax allows simultaneous waiting on several events.
The synchronization mechanism is based on a generalization of the semaphore concept. Mutual exclusion uses an even simpler mechanism.

Historical note

This multitasker is based on the same concept as the Mickey Mouse Multitasker ( MMM ) originally developed for the Walt Disney World Automated Admission Control System as a very fast real time operating system used in the turnstiles and ticket encoders. The MMM is believed to be the fastest real time executive for the Intel 8085. The key to the fast response was its macro implementation and the use of an AMD-9519A interrupt controller as the scheduler. The MMM has been rewritten to run on the iSBC 80/24 ( for an industrial control application ) with software scheduling to replace the AMD-9519A, and has been augmented with more convenient delay handling facilities.
A somewhat modified version of the Mickey Mouse Multitasker has been transported to the Motorola 68HC11 microprocessor as the MTK-11. Most functions have been retained except the task kill call. Since the MTK-11 is intended for stand alone, fixed program, dedicated application, this "reduction" is of little or no consequence. It also makes the Multitasker safer, since it is difficult to insure that all the housekeeping needed to properly terminate a task is done.

Availability

The MTK multitasker is available for the following micro controllers:

• MTK-85 Intel 8085
  
• MTK-11 Motorola 68HC11
  
• MTK-88 Intel 80188/80186
  
• MTK-H8 Hitachi H8
  
• MTK-SH Hitachi SH *
  
• MTK-166 Siemens C16x *
  
• MTK-68 Motorola Coldfire **
  
• MTK-90 Atmel AVR **