5160 no longer booting from good hard drive

[A-ko]

Hey all. Recently got a free 5160 out of an abandoned storage unit. All stock with 512K of ram, original 10mb IBM hard drive and IBM 5.25" floppy drive. The hard drive works, and after a little work, the floppy drive now works as well. When I got it home, it would boot from the hard drive, and then after a while, the allocation table was corrupted, but it'd still boot.

It started being iffy, so I formatted the hard drive (was mostly full of old wordperfect documents, nothing else of interest) and did a fresh, successful install of IBM DOS 5.0, which I use on quite a few of my old XT class machines.

However now it's developed a condition where if you turn on or reset the computer, it does the ram test, checks the floppy drive, and then the HDD light flashes for a split second and instantly reboots. The C: drive still works fine and is recognized if you boot from floppy, all files are accessible, seems to be plenty healthy, it just refuses to boot from it for whatever reason. Sometimes after this, the floppy light will be on and it'll seem to seek indefinitely, sometimes it does a test and stops. I am getting no startup errors. Successful ram test and then it does this.

Board dipswitch settings are correct and have not been altered.

Any idea what my next step would be to get it booting from the hard drive again? It should theoretically be able to no problem, it just doesn't seem to want to.

Thanks!

[Timo W.]

Did you do a simple format from DOS, or a proper low-level format? Do the latter if not done already. Let the drive warm up first by running it for half an hour.

[A-ko]

Did you do a simple format from DOS, or a proper low-level format? Do the latter if not done already. Let the drive warm up first by running it for half an hour.

what's the best option for doing a low level format on one of the OEM 10MB IBM drives? I've seen mentions that these drives are only supposed to be formatted using the IBM Advanced Diagnostics disk. Guess I'll seek out a disk image, unless I have it floating around somewhere...

[Timo W.]

Yes, using the diag disk.

[A-ko]

ended up running the DEBUG commands. A little fdisk, format, and DOS install, and we're up and running. I guess I was overcomplicating things assuming this was something at the hardware level. Thanks!

[modem7]

I've seen mentions that these drives are only supposed to be formatted using the IBM Advanced Diagnostics disk.

I have not seen anything from IBM to that effect, and I see no technical reason. I can imagine that IBM's standard line was something like, "Use the IBM provided method/s. IBM does not support other methods", which is not the same as, "Only the IBM method provides a reliable and optimized result."

[Timo W.]

I guess "only supposed" is from a user perspective. There's no BIOS or any other simple command you can use to do it, so as a user, you'd need to do it from the adv. diag disk. And not everyone knows you can jump into the routine using debug.

[A-ko]

I have not seen anything from IBM to that effect, and I see no technical reason. I can imagine that IBM's standard line was something like, "Use the IBM provided method/s. IBM does not support other methods", which is not the same as, "Only the IBM method provides a reliable and optimized result."

I meant more, this is the recommended/standard way of doing it, rather than a third party program.

I used the debug code and it worked perfectly. But about 2 hours later the 5160 blew a tantalum, haha!

[modem7]

But about 2 hours later the 5160 blew a tantalum, haha!

Tantalizingly close, until a tantalum threw a tantrum.