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scanner_cookbook 2011/09/20 23:00 scanner_cookbook 2011/10/17 00:07 current
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Usually the loader itself has to be loaded into the computer memory from tape, so there must be a built-in loader into the computer's ROM that can load a standard chunk from tape and execute it. In turn, the newly loaded code can load subsequent chunks using a different keying mechanism (that's why this code is referred to as "tape loader" or "turbo loader", the latter due to the fact that a custom loader is used to load data faster than the built-in loader).\\ Usually the loader itself has to be loaded into the computer memory from tape, so there must be a built-in loader into the computer's ROM that can load a standard chunk from tape and execute it. In turn, the newly loaded code can load subsequent chunks using a different keying mechanism (that's why this code is referred to as "tape loader" or "turbo loader", the latter due to the fact that a custom loader is used to load data faster than the built-in loader).\\
The built-in loader is often referred to as [[loaders:rom_loader|"CBM tape loader"]] or "ROM Loader". It's the one loader that is executed when one types LOAD at the BASIC interpreter. It is beyond the scope of this document to illustrate how a turbo loader is stored inside a standard chunk and executed. If you are interested in that piece of information be sure to read the [[analyzing_loaders#Turbo Loaders|document about turbo loaders]]. The built-in loader is often referred to as [[loaders:rom_loader|"CBM tape loader"]] or "ROM Loader". It's the one loader that is executed when one types LOAD at the BASIC interpreter. It is beyond the scope of this document to illustrate how a turbo loader is stored inside a standard chunk and executed. If you are interested in that piece of information be sure to read the [[analyzing_loaders#Turbo Loaders|document about turbo loaders]].
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  * **sof** is the tape image offset of the first pulse that belongs to the chunk\\   * **sof** is the tape image offset of the first pulse that belongs to the chunk\\
  * **sod** is the tape image offset of the first pulse that belongs to data section\\   * **sod** is the tape image offset of the first pulse that belongs to data section\\
-  * **eod** is the tape image offset of the pulse that is the last bit of the last byte of the data section (that includes the data checksum, if any is present)\\+  * **eod** is the tape image offset of the pulse corresponding to the first bit of the last byte of the data section (that includes the data checksum, if any is present after data)\\
  * **eof** is the tape image offset of the last pulse that belongs to the chunk. That is usually the last pulse of the trailer if there's one, otherwise it equals to eod\\   * **eof** is the tape image offset of the last pulse that belongs to the chunk. That is usually the last pulse of the trailer if there's one, otherwise it equals to eod\\
  * **xi** is an extra information parameter, a 32bit value, used to pass information to the //describe// section.\\   * **xi** is an extra information parameter, a 32bit value, used to pass information to the //describe// section.\\

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