The CPUs / PCBs/TLEs screen provides details on the availability of Process Control Blocks (PCB) and Time List Elements (TLE).
Each running process on the system requires one PCB. Additionally, a process may require one or more TLEs, if it has requested notification of an elapsed amount of time.
A PCB is considered low if it is allocated within the range of 0 to 254 and is considered high if 256 or greater. Older programs that do not have the High Pin enabled flag set within the executable are limited to the low range.
Any failure to allocate one of these resources shows in RED.