Dreamcast lba 150 offset?

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MoeFoh
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Dreamcast lba 150 offset?

Post#1 » Sun Sep 12, 2021 7:00 am

I been doing some reading, and still don't have a good understanding of the 150 lba offset used with gdi image dumps. Why does it exist in the first place? What is the LBA of track 3?
Last edited by MoeFoh on Mon Sep 13, 2021 6:14 am, edited 2 times in total.
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megavolt85
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Re: Dreamcast lba 150 offset?

Post#2 » Mon Sep 13, 2021 5:25 am

MoeFoh wrote:Oddly enough, dumpers were told to subtract 150 from the reported lba when the .gdi text was created, even though the reported lba was correct (45150).


you are confusing LBA and LSN
Logical Block Address = 45000
Logical Sector Number = 45150

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MoeFoh
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Re: Dreamcast lba 150 offset?

Post#3 » Tue Sep 14, 2021 1:39 pm

megavolt85 wrote:
MoeFoh wrote:Oddly enough, dumpers were told to subtract 150 from the reported lba when the .gdi text was created, even though the reported lba was correct (45150).


you are confusing LBA and LSN
Logical Block Address = 45000
Logical Sector Number = 45150


That makes sense. You're the first one to mention 'Logical Sector Number'.
“The problem with the world is that the intelligent people are full of doubts, while the stupid ones are full of confidence.”
- Charles Bukowski

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megavolt85
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Posts: 1835

Re: Dreamcast lba 150 offset?

Post#4 » Tue Sep 14, 2021 3:32 pm

Снимок экрана от 2021-09-14 22-29-39.png


read service documentation
Gdfm_s132e.doc
(470 KiB) Downloaded 102 times

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MoeFoh
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Re: Dreamcast lba 150 offset?

Post#5 » Tue Sep 14, 2021 4:51 pm

DOC file in PDF format:
Attachments
Dreamcast GD-ROM Specifications from SEGA.pdf
(1.77 MiB) Downloaded 125 times
“The problem with the world is that the intelligent people are full of doubts, while the stupid ones are full of confidence.”
- Charles Bukowski

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