Olivetti m380 issue

[Marmotta]

Hi! I’am a Italian vintage computers collector, now I try to restore a big Olivetti m380-xp3. First time I have fix the floppy drive controller on motherboard (d765 and some 74xxx ic changed) now the controller work good and I can read a 5.25 360k and 3,5 720k floppy’s. The cmos is gone, and I need to run a setup from floppy disk, but every time a try to boot, it hang just before giving the prompt. With any boot disk, and with internal controller or isa external controller… with any drive. I have changed all caps, simm on memory board, the two dma chips. No way :-( …where is the problem?

Video:

Sorry for my poor English

 

[Marmotta]

I tried without the nvram chip (bios default, hdd support is disabled). I can use a external hdd controller with hour bios. Hdd work but the problem remain the same, load msdos.sys, io.sys but hang on command.com… what’s happen when it load the command.com?