SWTPC SWTBUG® (SWATBUG) MONITOR ROM
One of the features of the SWTPC 6800 Computer System is that the conventional programmer’s console has been replaced with a monitor ROM. The programmer’s console consists of all the pretty switches and lights often found on similar microcomputers that are used to bootstrap the system after power up. The programmer’s console not only raises the cost of the system, but more often than not is confusing and tedious to use for both
SWTBUG® is the name of the monitor program used in the SWTPC 6800 Computer System. It might be thought of as kind of a
Features of the SWTBUG® ROM include:
∗Memory Examine and Change
∗Program loading from cassette or paper tape thru the control interface or thru I/O port # 0.
∗Program saving to cassette or paper tape
∗Go to user program
∗Display contents of registers
∗Erase SWTPC
∗SWTPC
∗Byte search
∗Breakpoint debugging
∗Vectored hardware and software interrupts to user defined addresses
SWTBUG® is a permanently stored program and cannot be erased or lost by either a loss of power or user program error. It is always resident in the computer while power is ON and need never be loaded into the machine. Subroutines within the ROM are documented and available to the user to simplify programming and conserve on the use of user RAM memory. Character input and output, string output and return to monitor are just a few subroutines available to the user.
SWTBUG® is a 1K byte program and is addressed high in memory, far above the amount of RAM memory required for most user programs. Since SWTBUG® does require a small amount of RAM memory for operation, a 128 byte scratchpad RAM has been implemented on the processor board so that no external user RAM memory is required for monitor operation. There is even enough extra room in this RAM so that short programs such as memory diagnostics can be loaded into and run from the scratchpad RAM without requiring any external user RAM memory. Extra care however must be exercised to avoid overstoring any memory locations required for proper monitor operation. Complete
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