Timeline for Boot sector code which can boot both MS-DOS and PC DOS
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| 21 hours ago | comment | added | user3840170 | @ecm Yes, that is a disadvantage. Though one would only hit it in the case of the DOS-BIOS file being properly installed, but the BDOS file not. For private use it just might be acceptable. | |
| 22 hours ago | comment | added | ecm | @user3840170 Yes, it does. But you're suggesting not to check for the DOS filename. That means if the disk is not bootable with the original loader then it won't work with yours either. But if you don't check the name it is more likely to lead to a crash rather than an error message. | |
| 22 hours ago | comment | added | user3840170 | @ecm Doesn’t the original boot sector already do that? | |
| 23 hours ago | comment | added | pts | I think I can write all this to fit to 512 bytes, based on the answer and the comments. I just wanted to see what I can reuse. | |
| 23 hours ago | comment | added | ecm | @user3840170 You still have to load the DOS module's directory entry to 00520h though. | |
| yesterday | comment | added | user3840170 | Given that for DOS 3.30+ the boot sector only needs to load (three sectors of) the DOS-BIOS, one can just skip checking if the name of the BDOS file matches, and instead probe for the other name of the DOS-BIOS file. So this can be made essentially free in terms of code size. | |
| yesterday | comment | added | ecm | Better link: github.com/microsoft/MS-DOS/blob/… Problem with the v4.00 msboot is it expects the msbio file to start in the first cluster aka cluster 2 (and for msload / 1536 bytes to be consecutive in the file system). MS-DOS v5 or v6 may have fixed that problem. | |
| yesterday | history | edited | Jerry Coffin | CC BY-SA 4.0 |
added 125 characters in body
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| yesterday | history | edited | Jerry Coffin | CC BY-SA 4.0 |
added 37 characters in body
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| yesterday | history | edited | Jerry Coffin | CC BY-SA 4.0 |
edited body
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| yesterday | history | answered | Jerry Coffin | CC BY-SA 4.0 |