I've had this happen with tons of blinking chars on certain bootups on my 486 after changing memory timing settings to something far tighter. Video bios screwup, at the fault of the motherboard's PCI quality, assuming. Was an S3 Trio64 PCI card.

I also had older Nvidia AGP cards on newer motherboards do the same thing, only this time with frying 🙁

I had on my old Tandy Trs-80 m4, some issues with the ram. It would display random characters, and spit out errors. Googled it, and sure enough; Memory probs. However, I have yet to see what you have described. I have no 486 unfortunately, however I have a Packard Bell Pentium MMX-166, and before that a 386sx-20. The only 486 I've ever had was a lame Sx-25, which can do most old computer tasks, save for some games.

Well, the piece of video hardware that disgraced this rig happened to be from Trident.

Up to this point I was more or less convinced it might have been an error message triggered by the bios that programmers simply forgot to make more specific. Also there's this possibility of faulty ram tempering with a value pointing out at a particular address containing a block of text from the rom; say it was set to display a status screen, now it would have been displaying a contiguous, likely unused block of 0x53's stored somewhere else in the rom.

Surely I'm stretching it, but it's not technically impossible. Nevertheless, when memory starts failing, you can almost always expect instability to follow along quickly, but that wasn't the case at all.

But now as I'm done writing what you read above, I've been able to recall something else. It might have been a virus, for another PC, much older and slower, exhibited the exact same problem right after running this game called "Sharkey's 3D Pool" from a floppy.

Almost certainly it was a virus.

If it happens immediately at power-on with a board lacking the ability to flash the BIOS then virus is highly unlikely, unless it overwrote the BIOS settings in some incredibly strange way. Chances are more likely faulty memory OR possibly a glitch during the system startup which sent the CPU to the wrong startup address, which quite frankly could cause just about anything to happen. :P

Lo Wang wrote:

I remember many moons ago turning on my 486 and almost immediately seeing the entire display populated with the letter "S", and there was nothing I could do to stop it save for hitting the power button.

This happened to me twice in my entire life and I wouldn't know what to blame it on. My memory's sketchy to say the least, so it could just be that the bios was unable to find a particular device. Maybe it was a faulty dos booting sequence, an evil virus or even just the the letter "S" being stuck on my keyboard, though I have no recollection of the screen slowly filling up with S'. I don't know what made it go away either, it just went away on it's own.

That's about as much as I have left in my memory bank. Any thoughts? anybody else ever experienced this?

Incidentally there is a good chance that is your problem 🤣

Very good chance indeed!

Have you ever had a good look at the Intel logo? It looks like a circle, doesn't it? But it's not a circle. It starts looping back onto itself before the circle can be completed.

How many degrees are in a circle? 360. And what is that Intel logo doing? It's backtracking and doing a 180.

180 + 486 = 666

Who has a name that begins with S? Satan, that's who.

You were right to turn off the PC when you did. The dark one may have been coming for you. If the PC had been left on, you might have been tempted to start dancing, read a Harry Potter novel, play D&D, or smoke cigarettes.

Consider yourself lucky, my friend.

Talk about losing it 🤣

Haha, I will take that as the definite answer 🤣

leileilol wrote:

I've had this happen with tons of blinking chars on certain bootups on my 486 after changing memory timing settings to something far tighter

Out of curiosity, did you ever get a screen filled with just one character, blinking or not?

Thanks everybody for the insights.