Autobooting ST Programs

In the June 1986 issue of COMPUTE!, you explained how to make an ST program autoboot (load and run when you turn on the computer) simply by putting the program in a disk folder named AUTO. I have used this method and it seems to work for every program except 1ST Word, the word processor supplied with the ST. Is it possible to make this program autoboot? Also, I have tried to autoboot programs in medium resolution with a color monitor. Can you tell me whether it's possible to autoboot a program in medium instead of low resolution?

Raymond Norris

As part of the boot process (caused when you turn on the power, press the reset button, or unplug the video cable) the ST checks the disk in the drive to see whether it contains a folder named AUTO. If so, it loads and runs the first program in AUTO which ends with the filename extension .PRG. These steps are performed by the BIOS (Basic Input/Output System) before the computer boots GEM, the ST's visually oriented operating system interface. Since you can't run a GEM program without GEM, you can't autoboot any program that takes advantage of GEM's windows, menus, icons, and mouse. Under ordinary circumstances, autobooting works only with TOS or TTP (TOS-Takes-Parameters) programs, which are limited to conventional text, keyboard, and input/output operations.

The answer to your second question involves the boot process as well. When it does a cold start, the ST defaults to low resolution for a color system or to high resolution for a monochrome system. If it can't find a .PRG program in an AUTO folder, the computer boots GEM and eventually looks for a file named DESKTOP.INF. The DESKTOP.INF file (created with the Save Preferences option) records the screen resolution, color palette, and much additional information about the desktop. If DESKTOP.INF is found, the ST reads it and sets the desktop to match your stored preferences. When you autoboot, however, the computer transfers control to the designated program before it has a chance to read DESKTOP.INF. As a result, you are always in low resolution after autobooting unless the program itself resets the video display for medium resolution. Low resolution is also in effect if the system finds neither an autobooting program nor a DESKTOP.INF file.

Other parts of the boot process check whether a cartridge is present or the disk contains a special boot sector. If either condition exists, control is diverted from the normal boot process to the machine language program found in the cartridge or the boot sector. Once this occurs, it's up to that program to set the resolution as needed.