Wrote demo monitor program for use by museums without reader, printer and disk

FRAMEWORK TO HOST MULTIPLE DEMONSTRATIONS

This is intended to have up to 16 demonstrations loaded in the machine, any of which can be selected easily by flipping on the Console Entry Switch for the desired routine and hitting the IRQ (Interrupt Request) button on the keyboard.

This has the interrupt handler for the keyboard, console printer and IRQ button which makes it easy to do input-output with these devices. There are defined areas where the calling demo code uses to know when its request is fulfilled. 

For example, a caller can put a flag FFFF into the input communication word, then activate the keyboard with a Keyboard Select. When the user presses a key, the interrupt handler reads the value of the key pressed and puts it into that communication word, then resets the keyboard. For typing on the console printer, the user stores any nonzero value in the output communication word, then issues the print to the typewriter. The interrupt handler will zero out that word when it has been successfully printed. 

SUPPORT FUNCTIONS PROVIDED TO MAKE DEMO WRITING EASIER

I included some support to make demo programs easier. Initially these are routines to print one character, a routine to print a string to the typewriter, and a routine to let the user type in an input string of up to 32 characters, terminated by the End of Field (EOF) key. 

FUTURE SUPPORT ROUTINES ANTICIPATED

I anticipate a routine that will format a number as a string of characters for typing and another routine that will accept a typed in number, do error checking and then return a numeric word as the output. 

WILL WRITE SOME DEMO ROUTINES NEXT

Some will be simple, such as a task that multiples two numbers a fixed number of times (many thousands) then ends. It will not require any access to the keyboard or console printer. 

Others will make use of the printer, such as a program to calculate and type the digits of PI to some set number of places.

Simple games, music playing programs and others are candidates to build as demonstrations.