MACHINE CODE TUTOR for the 2068 is a program on two cassettes and consists of 35 lessons. The advertising states 33 lessons. Most of the lessons have demonstration and examples following them. The 34th just explains the interrupts and the 35th is just a sign off message.
After the program/simulator section is loaded, a prompt appears on the bottom of the screen asking you to choose whether or not to load lessons. You are not allowed to specify what lessons although the 24 page manual supplied gives you that impression. The lessons are broken up into four groups (lessons 1 to 9, lessons 10 to 17, lessons 18 to 25, and lessons 26 to 35).
When a group of lessons has been loaded in, a menu page appears on the screen after the introduction. A prompt now asks that if you want to run the line highlighted, to press ENTER and if you want to select another lesson, to press SPACE.
If you choose to run the lesson, text appears on the screen explaining the Z80 commands the lesson is about. This may be a number of pages, after which, the menu returns to the screen with the next line highlighted. If that line is an example line and you key ENTER, you may get further text on the commands followed by a listing of the commands. That is followed by a screen containing an assembled program for demonstration.
Each line is arranged from left to right with the address in decimal, the contents of that address plus the contents of the following addresses that are tied in with that addresses’ contents, a label if one has been specified, and then the mnemonics.
The bottom of the screen displays the contents of the four flags, stack, and the registers. Only the registers needed for the program are displayed.
When you choose to run the program listed by keying R(un), the top line of the program is highlighted and explanation of what is to be done by that program. Anything outside of this will give an error statement. Even if you write a program into the assembler, there is no way to save it or get a printout of it.
Although the title screen calls it THE COMPLETE MACHINE CODE TUTOR, I do not consider it a complete tutor. I did learn to do various things with the display and attribute file. I also got the idea of how the computer prints characters to the screen, but I did not learn how it searches for a character keyed in.
By the way, the cassettes they send you do not have the tabs broken out so there is a great possibility that you could erase the whole cassette if you press the record button when you start to play the tape.
Available from Knighted Computers, 707 Highland St., Fulton, NY 13069(315) 593- 8219