|Source model||Closed source|
|Marketing target||Home computers|
|Platforms||MSX home computer architecture|
|Kernel type||Monolithic kernel|
|Default user interface||Command-line interface (COMMAND.COM), Text user interface|
MSX-DOS and the extended BASIC with 3½-inch floppy disk support were simultaneously developed by Microsoft and Spectravideo as a software and hardware standard for the MSX home computer standard, to add disk capabilities to BASIC and to give the system a cheaper software medium than Memory Cartridges, and a more powerful storage system than cassette tape. The standard BIOS of an unexpanded MSX computer did not have any floppy disk support, so the additional floppy disk expansion system came with its own BIOS extension ROM (built-in on the disk controller) called the BDOS. Spectravideo also released an MSX-DOS disk in conjunction with the SVI-707 which could be loaded into an MSX system. Once MSX-DOS has been loaded, the system searches the MSX-DOS disk for the COMMAND.COM file and loads it into memory. It not only added floppy disk support commands to MSX BASIC, but also a booting system, with which it was possible to boot a real disk operating system. In that case, the BDOS bypassed the BASIC ROMs, so that the whole 64 KB of address space of the Z80 microprocessor inside the MSX computer could be used for the DOS or for other boot-able disks, for example disk based games. At the same time, the original BIOS ROMs could still be accessed through a "memory bank switch" mechanism, so that DOS-based software could still use BIOS calls to control the hardware and other software mechanisms the main ROMs supplied. Also, due to the BDOS ROM, basic file access capabilities were available even without a command interpreter by using extended BASIC commands.
At initial startup, COMMAND.COM looks for an optional batch file named AUTOEXEC.BAT and, if it exists, executes the commands specified in there. If MSX-DOS is not invoked and Disk BASIC starts, a BASIC program named "AUTOEXEC.BAS" will be carried out instead, if present.
One major difference between MSX-DOS and MS-DOS 2.x was that MSX-DOS did not use the "boot sector" on the floppy to boot, but instead booted using the BDOS ROM routines, and, in a fashion much like MS-DOS 1.25, it used the FAT ID value from the first byte of the FAT to select file system parameter profiles for its FAT12 file system instead of from the BIOS Parameter Block (BPB) in the boot sector. Also, because there could be more than one floppy disk controller in two or more cartridge slots, MSX-DOS could boot from several different floppy disk drives. This meant that it was possible to have both, a 5¼" floppy disk drive and a 3½" disk drive, and the user could boot from either one of them depending on which drive had a bootable floppy in it.
On 10 August 1983, Paul Allen called Tim Paterson, original author of 86-DOS and MS-DOS 1.x, asking him to do a "Z80 version of MS-DOS" for the MSX standard.Cite error: Closing
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In addition, ASCII provided the following MSX-DOS2 Tools.
- SVI MSX User Manual (M-246) 1985 (Spectravideo MSX DOS Disk Operating System) Introduction to MSX DOS section 1.3)
- SVI MSX User Manual (M-246) 1985 (Spectravideo MSX DOS Disk Operating System) Getting Started section 2.1
- "Chapter 3 - MSX-DOS". MSX2 Technical Handbook. ASCII Corporation. 1987. https://github.com/Konamiman/MSX2-Technical-Handbook/blob/master/md/Chapter3.md. Retrieved 2020-03-27.
- MSX Technical Data Book
- (in ja, en) MSX-DOS 2 Tools (User's Manual). ASCII Corporation. 1989. https://archive.org/details/MSXDOS2TOOLS. Retrieved 2020-03-27.
Original source: https://en.wikipedia.org/wiki/ MSX-DOS. Read more