IDE - Dos2 - Manipulating files ?

Master (213)

05-11-2009, 10:25

Hiya all,

Last night i was doing some testing with some small files which i have in my code base.
Im using an IDE interface with DOS embedded to boot to dos2.2 and start my program.

Apparently it didn't work and after i had a look at it (Using the pc to compare the content of binary files) I noticed that as soon as the system booted with a DOS floppy it began manipulating .COM files who's size was smaller then 1Kb

I had .COM files with a size of 300 bytes.. after the system was started these files where exactly 1024 bytes.
As soon as i changed the filename to .DAT for example, the files where not touched ?

My question : WHY ? what did i miss ?

Thx,
Antal

By ro

Scribe (5059)

05-11-2009, 11:10

Clustersize

By Leo

Paragon (1236)

05-11-2009, 11:26

i noticed the same with SD v2.2 interface , file size change and got rounded to next 128 byte value.
i use gen80 to compile an assembly file , the binary result has its size rounded to higher 128 byte.
But if execute the compile command inside a .BAT file and i copy the file in other directory in the same
.BAT file before exiting , then file size is correct .

My guess is that it is linked to somesector/cluster size , which can explain your HD/FD difference since
cluster are probably not same size , just a guess....

it is very annoying because i use concat to concatenate binary results to make a .rom file
for 128kb megarom, hopefully i have that file.bat work around.

By Leo

Paragon (1236)

05-11-2009, 11:26

My guess is that it is linked to somesector/cluster size , which can explain your HD/FD difference since
cluster are probably not same size , just a guess....

By Whizzy

Master (213)

05-11-2009, 11:34

Ok,

Clustersizes and such. but why on earth did the OS prepend my file with random data? And not append ?
This way my program fails to load because it load the first X bytes of data, and now i get some weird crap back.

And..,. why didn't it change .DAT files ? but .COM files ?

Questions.????