The art of assembly language-preparatory work (II.)

Iv. simplification of names

The aforementioned tools, in the process of debugging procedures frequently used, for the convenience of application, if you can enter a few characters, not only save time, and can avoid errors. The user is able to concentrate and think about other details under the inertia reaction.
Simplifying the name is the simplest way, preferably with only one letter, because the length is equal, the file name behind it, you can take advantage of the system provided by the "F3" "Copy up" function, do not have to enter the line.

is to: edlin.com changed to E.com
Masm.exe changed to M.exe
Link.exe changed to L.exe
Debug.exe changed to D.exe
Symdeb.exe changed to S.exe
For example: After a program is completed, if you want to assemble it, just change the first letter.
C:\>e Myfile.asm (characters originally entered in the system)
Enter only "M" and then press "F3" to immediately change to:
C:\>m myfile.asm
In addition, if you do not need to LST and other files, then add a ";" Can.
C:\>m myfile.asm;
"L" and "D" can also follow the above method, it seems to be tricks, but in fact, the time and energy saved is remarkable.

V. reference materials

In addition to the specialized information, the programmer should prepare a variety of related output, entry, various peripheral equipment reference or manuals, etc. for easy access.
The most important is the software reference manual MS-DOS Software Reference, which has a variety of interrupt command usage specifications. Note that there are some interrupts that are the same as the IBM BIOS, and I recommend that readers do not use these interrupts, because during the call process, the BIOS will be transiting, slowing down the speed.
The second is the BIOS interrupt specification for IBM Programmer ' s Manual, which is a necessary tool for handling all peripheral devices.
Because it involves peripheral equipment, in the design of Chinese system, output, display and printing functions have to be modified, this manual should be thoroughly understood.
In addition to the keyboard input Code table, is also necessary for programming information, this book appendix III is a brief description of the code table.
If you are writing an application, the above information is sufficient to deal with, but if the system is involved, you still need to understand the system memory space arrangement, the following table is IBM microcomputer memory area structure. All kinds of brand design concept Although there are differences, but very similar.
System Dan Site Functional use
┌──────────────┐
0000 0000h│ Interrupt Call Table │
├──────────────┤
0000 0500h│dos and System Operation area │
├──────────────┤
0000 4c00h│ Peripheral Control Program │
├──────────────┤
0000 5400h│command Application │
├──────────────┤
0000 0e0a0h│ User Operating Space │
├──────────────┤
000A 0000h│ Screen buffer (VGA) │
├──────────────┤
000B 0000h│ Screen buffer (cga,ega) │
├──────────────┤
000C 0000h│ems Memory Expansion Area │
├──────────────┤
000F 0000h│rom BIOS Program Area │
└──────────────┘
The above system segment, the transfer into the section of the register, the original 000AH should be 0a00h, Yu Tong.
The starting point of the user's operating space is different from each other's design.
Section II Making of application tools

One, the connection target file (OBJ files)

After the program is complete, the connection between each other is bigger and harder, sometimes it is the change of the structure, sometimes the file name. Whatever it is, it needs to be maintained, and it has a lot to do with productivity.

Therefore, you need to first create a Do.bat execution file, which reads:
1:link/m @XXXX
This XXXX is a log file, which records all required to join the target file name, if any changes, directly change this file can be.
When joining, execute do.

For example: To make Draw.exe file, there are dr1.obj. Drn.obj and Dr-seg.obj, the contents of this XXXX file should be:
1:dr-seg+
2:dr1+dr2+.. Drn
3:draw,draw, the
When you perform a do, if there are no errors, the resulting draw.exe and draw.sym can be tested.

It may also be added after article III:
4:symdeb (or only s) Draw.exe Draw.sym
Like this, in the early stages of development, can be tested immediately. If there is no need to be connected again, the fourth will be a. bat file, which can be carried out at any time.

It is also important to note that in order for the executable program to start with the specified starting point, the header name of the start point is added after the end format of the original file. asm.
This tag, regardless of how many, joins the target file with the first found title as the only entry. If there are many programs, and many programmers are involved, they often use their own portals when they separate tests, and once they are joined together, errors can occur.
The solution is by the programmer responsible for the join, prepared in advance of the XXXX log file, with the entry tag of the program on the front can be. Of course, the deletion of the title after the other program is also, but not as efficient as the former method.