Start-Up Sequence - ENCAD CADJET 2 Service Manual

Theory of Operation
3.5

Start-up Sequence

Immediately after power-up, the following sequence of events takes
place:
1. System registers in the microprocessor are initialized.
includes initializing the clock generator. Prior to this, the clock
runs at about half its normal speed.
2. All LEDs are turned on and off. The fan is turned off.
3. The display is initialized and the copyright message is displayed.
4. A checksum of the EPROM is performed.
5. The first four kilobytes of RAM are tested to make sure enough
RAM is working to run the compiled C code.
6. Execution of the compiled C code begins.
7. RAM size is determined, and all RAM is tested. Status information
is shown on the display during the test. "Memory OK" is displayed
at the end of the test.
8. The code in the EPROM is copied to RAM, and the program
begins executing out of RAM.
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CADJET 2