CoffeeOne wrote on 2023-01-30, 19:35:Yes, you can upload a good picture of your board.
Here's my board. To me the jumpers seem correctly set but who knows, maybe something slipped my attention 😀
MMaximus wrote on 2023-01-31, 18:28:CoffeeOne wrote on 2023-01-30, 19:35:Yes, you can upload a good picture of your board.
Here's my board. To me the jumpers seem correctly set but who knows, maybe something slipped my attention 😀
VLI486SV2GX4.JPG
Oh.
I am a bit surprised, I thought you have the floppy problem with a CPU that supports L1 write back.
But you have the problem with a 486SX, so different thing.
Jumper setting seems to be good for 486SX.
So what about your floppy controller? Is it a Vesa Local Bus one or an ISA one? Jumper settings correct? 😁
Is the floppy controller known good (working on another board)?
CoffeeOne wrote on 2023-01-31, 19:37:Oh. I am a bit surprised, I thought you have the floppy problem with a CPU that supports L1 write back. But you have the problem […]
MMaximus wrote on 2023-01-31, 18:28:CoffeeOne wrote on 2023-01-30, 19:35:Yes, you can upload a good picture of your board.
Here's my board. To me the jumpers seem correctly set but who knows, maybe something slipped my attention 😀
VLI486SV2GX4.JPG
Oh.
I am a bit surprised, I thought you have the floppy problem with a CPU that supports L1 write back.
But you have the problem with a 486SX, so different thing.
Jumper setting seems to be good for 486SX.So what about your floppy controller? Is it a Vesa Local Bus one or an ISA one? Jumper settings correct? 😁
Is the floppy controller known good (working on another board)?
Yes, both the floppy controller and FDD are known good. Run of the mill ISA Goldstar Prime2 card and 1.44 TEAC FDD. I've also tried with different RAM so I'm not sure what the issue could be 🤔
MMaximus wrote on 2023-01-31, 19:39:CoffeeOne wrote on 2023-01-31, 19:37:Oh. I am a bit surprised, I thought you have the floppy problem with a CPU that supports L1 write back. But you have the problem […]
MMaximus wrote on 2023-01-31, 18:28:Here's my board. To me the jumpers seem correctly set but who knows, maybe something slipped my attention 😀
VLI486SV2GX4.JPG
Oh.
I am a bit surprised, I thought you have the floppy problem with a CPU that supports L1 write back.
But you have the problem with a 486SX, so different thing.
Jumper setting seems to be good for 486SX.So what about your floppy controller? Is it a Vesa Local Bus one or an ISA one? Jumper settings correct? 😁
Is the floppy controller known good (working on another board)?Yes, both the floppy controller and FDD are known good. Run of the mill ISA Goldstar Prime2 card and 1.44 TEAC FDD. I've also tried with different RAM so I'm not sure what the issue could be 🤔
Hi, this is hard now.
One maybe silly question:
In BIOS, when you set "Boot Up Floppy seek" to enabled, do you hear some noise from the floppy drive???
Yes, I've tried with "boot up floppy seek" enabled and disabled. The floppy correctly seeks at boot - seek noise and LED lighting up. But when trying to boot from a DOS floppy disk, there's one short access to the floppy and then nothing. The boot disk works correctly as verified on other machines. If I put a non-booting floppy in the drive, I don't even get the usual message "insert system disk and press enter" - nothing happens 🤔
MMaximus wrote on 2023-02-02, 11:57:Yes, I've tried with "boot up floppy seek" enabled and disabled. The floppy correctly seeks at boot - seek noise and LED lighting up. But when trying to boot from a DOS floppy disk, there's one short access to the floppy and then nothing. The boot disk works correctly as verified on other machines. If I put a non-booting floppy in the drive, I don't even get the usual message "insert system disk and press enter" - nothing happens 🤔
Hi, and you test only with the ISA Floppy/harddrive/serial controller and the graphics card. Is it correct?
Or are there any other cards inside?
Are you able to boot the system from an IDE drive? (When you have MS DOS 6.2 installed for example)?
MMaximus wrote on 2023-01-31, 18:28:CoffeeOne wrote on 2023-01-30, 19:35:Yes, you can upload a good picture of your board.
Here's my board. To me the jumpers seem correctly set but who knows, maybe something slipped my attention 😀
VLI486SV2GX4.JPG
Hi again, something indeed slipped my attention 😀
What RAM is inside?
Please try moving the second module to slot 3, so that 1 and 3 is populated (not 1 and 2).
Good observation - thanks! Following your last message I had a look at the mainboard manual and noticed that some slots supposedly don't support double-sided RAM, so I did as per your suggestion but then the system reported only 1Mb RAM as opposed to 4Mb. (I am using a pair of double-sided 4Mb FPM SIMMS, 70ns IBM branded.)
I've then swapped the IBM RAM for one stick of single-sided 4Mb FPM SIMM, Daewoo branded (I have a pair of these but only used one in SIMM slot 0 for testing). I managed to make the floppy drive boot, but then I switched off the system and it wouldn't boot anymore. I haven't been able to boot from a couple of known good <540Mb IDE drives, but IIRC I managed to boot from a 512Mb CF a few weeks ago. I've also tried with a VLB multi-I/O, but no luck. The board seems very temperamental, I've noticed there's one capacitor near the CPU socket and I'm wondering if it could be the problem, even though it looks OK visually...
MMaximus wrote on 2023-02-04, 19:34:Good observation - thanks! Following your last message I had a look at the mainboard manual and noticed that some slots supposedly don't support double-sided RAM, so I did as per your suggestion but then the system reported only 1Mb RAM as opposed to 4Mb. (I am using a pair of double-sided 4Mb FPM SIMMS, 70ns IBM branded.)
I've then swapped the IBM RAM for one stick of single-sided 4Mb FPM SIMM, Daewoo branded (I have a pair of these but only used one in SIMM slot 0 for testing). I managed to make the floppy drive boot, but then I switched off the system and it wouldn't boot anymore. I haven't been able to boot from a couple of known good <540Mb IDE drives, but IIRC I managed to boot from a 512Mb CF a few weeks ago. I've also tried with a VLB multi-I/O, but no luck. The board seems very temperamental, I've noticed there's one capacitor near the CPU socket and I'm wondering if it could be the problem, even though it looks OK visually...
Hello,
Yes, so something is clearly wrong with the mainboard (or RAM or both).
Since you have also problems with harddisks, it's not related to floppy disk access only.
I don't have more ideas at this point.
But I am really sure, when you would try to install windows 95 or windows 98 (not sure if you would be able to do it), you would have bluescreens and the installation would fail....
MMaximus wrote on 2023-01-12, 18:42:I am currently experiencing the same problem with a VL/I-486SV2GX4 board - it seems to POST fine but then refuses to boot from floppy - I hear 2 short sounds and it hangs there. This thread reminds me I might need to update the BIOS and see what happens 😀
A little late, but I think I can add some information and a solution.
This diva of a board has cost me two weekends in a row. I had exactly the same problem while trying to boot from the 3 1/2" floppy: "Starting MS-DOS", then couple more ticks from the drive and silence. My config:
At first I suspected the 40MHz on the VLB and / or the overclocking. But no matter what I tried, nothing helped. VLB cache controllers, VLB multi-I/Os, run-of-the-mill ISA multi I/Os, loading BIOS defaults, nothing prevented the problem. I did not swap the CPU or changed any CPU related jumpers, though, as the board was otherwise rock solid.
Hope that helps anyone.
jewesta wrote on 2025-04-27, 13:11:A little late, but I think I can add some information and a solution. […]
MMaximus wrote on 2023-01-12, 18:42:I am currently experiencing the same problem with a VL/I-486SV2GX4 board - it seems to POST fine but then refuses to boot from floppy - I hear 2 short sounds and it hangs there. This thread reminds me I might need to update the BIOS and see what happens 😀
A little late, but I think I can add some information and a solution.
This diva of a board has cost me two weekends in a row. I had exactly the same problem while trying to boot from the 3 1/2" floppy: "Starting MS-DOS", then couple more ticks from the drive and silence. My config:
- AMD Am5x86 X5 133AD @160MHz (4 x 40MHz)
- 2 x double sided 32MB RAM in every other slot = 64MB
- Latest BIOS (I think) with write-back fix
At first I suspected the 40MHz on the VLB and / or the overclocking. But no matter what I tried, nothing helped. VLB cache controllers, VLB multi-I/Os, run-of-the-mill ISA multi I/Os, loading BIOS defaults, nothing prevented the problem. I did not swap the CPU or changed any CPU related jumpers, though, as the board was otherwise rock solid.
- Booting 6.22 was possible from HDD any time.
- The problem only existed with MS-DOS (tried 6.22), Win95 and Win98 boot disks.
- Novell DOS 7 and Win2k boot disks were always working fine!
- Weirdly I could boot and install 6.22 from the 5 1/4" floppy. That was a last resort solution I didn't really think had any chance of working but did. No idea, why!
- What finally solved it was enabling the IRQ 12 jumper, i.e. PS/2 mouse! I can see on your mobo picture that it is off. Yes, that actually resolved the boot from 3 1/2" problem for me. It cost me four days of experiments and now the floppy boots every time. I think this is definitely not a placebo. Complete mystery.
Hope that helps anyone.
Thanks for this detailed explanation! 👍 In retrospect, I think I blame user error on my part. I actually sold that board a few weeks ago, but before I did I wanted to see if I could fix the problem and I found out it actually worked flawlessly 🤯 I suspect I was using a faulty part somewhere in the chain, maybe FDD, controller card or one of these "industrial" CF cards (which come to think of it have given me more trouble than regular CF cards over the years 🙄)
FWIW here's a video I made before selling the board:
