Hello again! I just wanted to report back for all of you who helped me and gave great inputs.
Thanks for the CHS/LBA info. This is an IDE Flash module that goes directly into the MBs slot. It doesn't allow to connect another device beside it, so it also doesn't have a master/slave jumper. It has a capacity of 512 MB. I tested it on another PC, from around 2000, which auto-detected it as C/H/S 993/16/63 (no boot-up as it was still empty at that time, I just did the BIOS auto-detection). On the 486 I've put that in for the IDE device as custom type 82. The other values, LZ and WP, I left at 0. I assume for a flash drive they are simply not important. But it doesn't boot. It halts with the error message: "partition signature != 55AA" I've personally checked: all partitions and the MBR have that signature. I managed to find an old external USB HDD which has an IDE interface inside, and I connected the flash module to my regular PC. > # dmesg | tail > [23705.522176] scsi 7:0:0:0: Direct-Access TRANSCEN D 0000 PQ: 0 ANSI: 0 > [23705.522746] sd 7:0:0:0: Attached scsi generic sg3 type 0 > [23705.523265] sd 7:0:0:0: [sdc] 1000944 512-byte logical blocks: (512 MB/489 MiB) > [23705.524141] sd 7:0:0:0: [sdc] Write Protect is off > [23705.524145] sd 7:0:0:0: [sdc] Mode Sense: 27 00 00 00 > [23705.525012] sd 7:0:0:0: [sdc] No Caching mode page found > [23705.525018] sd 7:0:0:0: [sdc] Assuming drive cache: write through > [23705.528556] sdc: sdc1 sdc2 sdc3 > [23705.531653] sd 7:0:0:0: [sdc] Attached SCSI disk > # parted /dev/sdc print > Model: TRANSCEN D (scsi) > Disk /dev/sdc: 512MB > Sector size (logical/physical): 512B/512B > Partition Table: msdos > Disk Flags: > > Number Start End Size Type File system Flags > 1 32,3kB 52,7MB 52,7MB primary > 2 52,7MB 74,0MB 21,3MB primary > 3 74,0MB 480MB 406MB primary fat16 boot As you can see, the third primary partition is for FreeDOS. I've decided to create a 50 MB partition for DR DOS and a 20 MB partition for MS-DOS or any other DOS I want to test (like PC DOS, PTS-DOS). The third partition has been made bootable with "format c: /s /q". I've also rewritten the MBR using "fdisk /mbr". All partitions are formated. The first two partitions are otherwise empty. I've also used Linux's dd (e.g. "dd if=/dev/sdc1 bs=512 count=1 of=bootsec1.bin") to check if the boot signature 55AA is present on all partitions + on the MBR and it is. Thinking logically: If the BIOS wouldn't check, it should boot. The MBR code should find the active partition #3 and chainload the bootsector. This should include the bootcode for FreeDOS, since I've formated it with /s and the system files are on the parition. I hate it when a BIOS checks stuff that it rather shouldn't care about! Any other error message and it could have been FreeDOS, but I am sure this one if from the BIOS _before_ it executes the MBR boot code. Maybe the next time I will try only one partition first... Anyway: again, I've come to a halt for now. I appreciated your help. Happy 2017. Userbeitrag. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user