Available as freeware with most features enabled or with few features enabled for a small code size. It is without resrictions, time limits or commercial use limitations.
In addition to the standard feature set supported by most real-time kernels, the Abassi RTOS can be configured with many features unmatched in the industry. These features add robustness and code savings, and include:
Abassi supports major 8051/8052 development tools, including Keil/C51.
Don't settle for half a RTOS! Even with all features enabled, Abassi still consumes less memory than the minimum configuration of most kernels. And you get advanced priority inheritance, asymmetric round-robin scheduling, starvation protection, and much more. Or, if memory footprint is paramount, Abassi scales to a minimum size that can't be matched.
+ Runtime service creation / static memory
|+ Multiple tasks at same priority||<4000 bytes|
|+ Runtime priority change
+ Mutex priority inheritance
+ Task suspension
|+ Timer & timeout
+ Timer call back
+ Round robin
|Full Feature Build (no names)||<12350 bytes|
|Assembly code size||553 bytes|
|Fast Interrupts Enabled||+94 bytes|
|Base Kernel||41 bytes|
|+ Task||22 bytes|
|+ Semaphore||8 bytes|
|+ Request||9 bytes|
|+ Mailbox||17 bytes|
|Measured using current software release, configured for 8052 at 11.0592 MHz and Keil μVision, Version 4.10|
For your exact data memory requirements, please consult the Porting Document that applies to your design environment.