Machine Language Made Easy

by Lyle Giese (LYLEG on DELPHI) It looks like this month we will finish up the Sequential File Reader. So what will I do next month? Let me know what YOU want written about. I really want to write about something that will interest you, and the best way to do that is to tell me! My DELPHI username is LYLEG, and if you are on Genie tell deb! and she will forward the comments to me. When we left off last month we just opened the file to be read and now are ready to decide if we want to send it to the printer or the screen. Of course, we first print a message to the screen asking Screen or Printer? In line 1280, we get a character from the k...

Machine Language Part VI by Lyle Giese (LYLEG on DELPHI) Last month I started explaining my SEQ file reader for you. I got up to putting the opening message on the screen. Next we must get from you (the user) the filename of the file you want printed out. We have to start by deciding where we are going to store the filename. In BASIC, BASIC takes care of that automatically. But of course that convenience is offset by the slow speed of BASIC. In this program I decided to use the cassette buffer at $033C. Again I will use the index and index+1 memory locations to point to the filename. I will also need another variable for the length of the...

Machine Language - Part V by Lyle Giese (LYLEG) This month, I decided to keep my promise to write a program in a label based assembler. The program is a SEQ file reader with the output going to the screen or the printer. The printer device can be selected (4-7) as well as the secondary address (limited to 0-9). The reason for using ML here should be obvious to anyone who has written a file reader in BASIC. You go to sleep after about the second screen full of information. Speed loaders of course help, but nothing can beat ML here. I wouldn't expect ANYONE to enter this program without a label based assembler. This program would be jus...

by Lyle Giese (LYLEG) Welcome to this month's instalment of how to talk to your computer in its own language! First of all, I know that at least one person reads my column! Bill Brier (a.k.a. TROUBLESOME) reports that the KERNAL routine CHROUT($FFD2) does not corrupt the Accumulator even though CBM's Programmers Reference Guide says so. He has used that routine on the 64 and C-128 without ever seeing the Accumulator change. (Probably on one or more of the earlier PET's it did change the Accumulator's value and CBM made the KERNAL chart from some of the old PRG'S. But that's just speculation.) This month's progr...

by Lyle Giese DELPHI Mail: LYLEG Last month, I showed you how to print to the screen. This month we will print the alphabet to the screen. And next month we will look into disk I/O. Now don't let this scare you away. It is really not that hard. It does take a few steps more than you would need in BASIC, but the increase in speed is well worth it. To start off here is this month's program. Again I am using the simple assembler put the program in memory. .A C000 LDA #$01 .A C002 LDX #$04 .A C004 LDY #$07 .A C006 JSR $FFBA .A C009 LDA #$00 .A C00B JSR $FFBD .A C00E JSR $FFC0 .A C011 LDX #$01 .A C013 JSR $FFC9 .A C016 LDY #$41 .A ...

by Lyle Giese DELPHI Mail: LYLEG One of the Tools of the trade for Machine Language Programming! When you wanted to learn about BASIC you read and played directly with BASIC programs. Using the BASIC editor, you listed programs to the screen and printer, wrote simple programs, and modified others. In order to do that you used BASIC itself in the form of its editor. The equivalent of that for ML is the Monitor. There are several good PD monitors available and we have some of them in our databases in the Flagship under Languages & ML. One of the simpler ones is Supermon, written by Jim Butterfield. It's features became the standard ...

by Lyle Giese DELPHI Mail: LYLEG This is the first in a series of columns to help ease the newcomer into the world of Machine Language. I am still not sure how I got into this job, but I will give it my best! It is quite hard to get started in Machine Language programming, but just like the BASIC in your first computer, once you know a little about it is not that difficult. This column will be based on the 6502 & 6510 microprocessors that are used in the Commodore 64 & Vic-20, Atari 400-600-800 series machines, and in some Apples. The 8500 processor in the C-128 is a direct cousin of the 6502. All instructions for the 6502 will do...