Hello! W dniu 2011-01-19 05:18, Hoffmann-Vetter, Martin pisze: > Yes, it loads 54 sectors starting at Track 1 Sector 21 to memory bank 1 address 0. After reading sector 22 the next sector is sector 0 on the next track. So it loads IO.SYS at 10000 (6509) or 0000:0000 (8088) and MSDOS.SYS at 11800 (6509) or 0180:0000 (8088). Correct. In fact, the first kilobyte of IO.SYS are interrupt vectors, where INT 07h points to 0044:0000. This jumps to 0040:0126, which apparently initializes MSDOS.SYS by calling 0180:0000, and then uses DOS INT 21h routines to load the COMMAND.COM file. So INT 07h is the warm start procedure, triggered by circuitry on the board according to Ruud's expanation. So it looks like actual code of IO.SYS is at segment 0040 and MSDOS.SYS at segment 0180. Now I am looking at this initialization code with IDA Pro disassembler :-) Regards, Michau. Message was sent through the cbm-hackers mailing listReceived on 2011-01-19 11:00:22
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