> Which means that, in order to perform large file operations, we need to go through the dance above multiple times in a loop. And that’s why DJGPP is slow: if the DPMI host has to switch to real mode and back for every system call, the overhead of each system call is significant.
Not as bad as it sounds, because INT 13h (which is the BIOS function that DOS uses to read from disk) was limited to 64k anyway, IDE was limited to 128kB per command (probably never more than 64k on DOS), and disk drive buffers were mostly measured in the kilobytes. Which means that every 64k read involved I/O across the bus, and most likely involved actual spnning rust stuff, all of which makes a protected-mode/real-mode thunk look fast in comparison.
Hello, Julio Merino! I liked your post! I try to generate a GNU Cobol compiler within of the FreeDOS ambient ... this last I have it installed in DOSBOX Staging in the Debian Linux. There is 2 or 4 years we try to execute the work, but always stop in the files names than the DJGPP doesn't recognize ... tiy can help us? That is the link to the discuss:
Not really. The problem is that I don't have the time to go through a long email thread to guess what the specific problem is. And I'm no DJGPP expert.
> Which means that, in order to perform large file operations, we need to go through the dance above multiple times in a loop. And that’s why DJGPP is slow: if the DPMI host has to switch to real mode and back for every system call, the overhead of each system call is significant.
Not as bad as it sounds, because INT 13h (which is the BIOS function that DOS uses to read from disk) was limited to 64k anyway, IDE was limited to 128kB per command (probably never more than 64k on DOS), and disk drive buffers were mostly measured in the kilobytes. Which means that every 64k read involved I/O across the bus, and most likely involved actual spnning rust stuff, all of which makes a protected-mode/real-mode thunk look fast in comparison.
Hello, Julio Merino! I liked your post! I try to generate a GNU Cobol compiler within of the FreeDOS ambient ... this last I have it installed in DOSBOX Staging in the Debian Linux. There is 2 or 4 years we try to execute the work, but always stop in the files names than the DJGPP doesn't recognize ... tiy can help us? That is the link to the discuss:
https://sourceforge.net/p/gnucobol/discussion/cobol/thread/bf585faa58/?page=1
Everaldo
Sorry, I do not know what the issue is and following that thread is pretty confusing.
Is it confusion for the fact I don't speak English language?
Not really. The problem is that I don't have the time to go through a long email thread to guess what the specific problem is. And I'm no DJGPP expert.