took apart 486, now can't get back together

[budbd]

Haha, this is funny, need some advice from those who know about 486 machines. I have this old 486 machine that I bought at a garage sale, an AST, and its monitor. Tried it out, but got no picture, so I figuredd the computer was bad even though it seemed to power up and go through the use of the hard drive.
Once I took it all apart to learn from, noting the processor is an upgrade called a iNTEL dx40pr100(guess that means 100 mhz), 32 mg of ram(16mbx2) is in the two slots, which is alot for one of those.
I was throwing away the monitor when I noted one pin inside of the connector was smashed over, thus it must have been why there was no signal. Now I think, I can make my used 486 work for dos programs and learning purposes IF I CAN FIGURE OUT HOW THE FLAT CABLES WENT BACK, especially fore the serial cables, the printer cables, etc. If I get something backwards, will I burn out the motherboard? I can't believe I am doing this, cause I thought I would just part it out for parts if I ever came across a working 486 system, cheap, hard to do in my semi rural location, never were alot of computer user in the past as it is.
Also, when I went to put back the power supply to the motherboard, I notice the two power plugs are marked p8 and p9. The marking on the motherboard at the end of the row of pins says "P89". I figure that if I put in p8 first, then p9 then I have them in the correct sequence.

I have no software for this, can't believe I am messing with it, since it was really a mess when I got it, cause someone had taken out the cd drive and left the drive trays loose.

It should be really a vintage powerhouse, if I get it to working, and it would save me from having to purchase anything else, and this was practically free.

ALSO, WOULD IT BE SAFE FOR ME TO HOOK UP MY 6 YEAR OLD GATEWAY MONITOR TO THE 1995 15 PIN VGA CARD ON THE 486? IM MEAN, I SURE DON'T WANNA BURN OUT MY OLD GATEWAY MONITOR JUST TO SEE THE 486 WORK. I DIDN'T REALIZE THE CONNECTORS ARE THE SAME CONNECTION TYPES.

[GaryRouth]

Shouldn't hurt the Gateway monitor. The VGA connector didn't change much from the time of the 486 (today's 15pin is pretty much the same - only difference is that now everyone will eventually move on to the digital connectors for LCD, OLED, and such).

The power connectors go in side by side like you've figured out, with the side with the tiny spaces going on the side with the tiny pins [truly awkward to install under any circumstances, generally]. The black wires from the two connectors should be in the center when the two connectors are plugged in together.

You might be able to find a friend with an extra monitor cable lying about.

Sounds like fun
. . . Gary

[budbd]

Won't be able to fix the old "NEC" monitor with the bad pin, cause it was pretty rough, dirty, bad connector, and made a big "pop" when the screen hit something hard in the dumpster, haha.

The video card on this old 486 is a ATI, kind of a long thing, with two plug ins for the the only dual plug in arrangement on the mother board(at least I can't get that wrong). It looks as if ther are many empty slots that optional extra memory chips could actually reside.
There are two other slots I believe are called ISA slots, and three pci slots, though one is unuseable cause it is so close to the dual slot arrangement for video.

Someone had added an 8 bit board I found out was a mouse controller, but the mosue that came with it was a serial mouse connected to the small serial connector, that I believe is called "com 2". Anyway, I am hoping com 2 is the smaller serial connector, if I remember from years past(actually up to 1998, I only had a real nice 286 for word processing and vintage games).
ACtually, I wouldn't mind getting this thing going, and then adding a joystick port and a cd drive and 5 1/4 drive. I need to look, but am unsure if there is enough power cables for 5 1/4 and cd both. Would prefer a sound card in this thing as well, the speaker is rather small.
I have some vintage games and applications for DOS on cd and in 5 1/4, not to mention 3 1/2, which this thing already has and likely would take a replacement I have if the 3 1/2 didn't work anymore.

[diver203_98]

I actually still have my 486 and it works great. I also had a 5 1/4 floppy drive. Although it is in my desk in mint condition so it won't get damaged. I don't remember if I ever used it or not. The cable is still in my 486 so I still have that. I only replaced it when the programs got too much for it, and replaced it with the "current" one I have in my sig. Still I wouldn't part with it, my 486 that is. Good luck, and I hope you can get it running again.

[budbd]

Just read a tag on the back, that it was built on 12/23/93. Wow, now that REALLY FITS THE BILL OF "VINTAGE", being at least ten years old. VGA card is a vlb mach 64 ati, according to a paper sticker on one of the chips. Hard drive is about 650 megabytes.
This thing might have come with a 5 1/4 1.2 mb high density drive back then, cause I remember when cd drives were first starting to come out in large numbers for the home consumer in quanity, and I think around that time frame it was "iffy" that a computer came neew with a cd drive.

There is a big empty area up top that is open to the inside of the case(gonna have to block that off if it works)that could in theory take a cd drive and a 5 1/4, but there is only power for one dirive. This is a small mini or mid tower case.

I remember those days well, cause I was taking some college courses, and in a required course for learning advanced grammar and advanced writing, they had a bunch of APPLe 2 machines we had to use, slow as hell, and I thoroughly hated those things, had to go through two terms of course work with them. Almost makes me wanna go up town and buy one for two dollars where I bought my Tandy 1000sx just so I can get it going and hate it a whole lot more(but I am running out of computer workspace with three systems already in place and a fourth about to be reborn).

[budbd]

figured out as best I could to hook up the four power related wires and ground loop, and a few of the leds and powered up the computer with my monitor and it came on to a windows 95 screen eventually.

Unfortunately, I am having a heck of a time figuring out how to rehook up the serial mouse!

I believe that the smaller serial port is called "com 1", and the larger serial port is "com 2". The computer says I don't have a mouse connected. I tried switching the cables, and kind of gave up for the night.

ANYONE, IS "COM ONE" THE SMALLER SERIAL CONNECTION, OR THE LARGEST SERIAL CONNECTION? ALSO, IS IT POSSIBLE TO HAVE THE CABLE ON THE MOTHERBOARD INSTALLED BACKWARDS ON THE PINS? Maybe that is the problem.

Oh well, I am gonna regret just pulling apart an old computer for a long long time.

[GaryRouth]

If you're lucky, the com ports will have a little silkscreened label next to their connector pins on the motherboard. Most of the boards had Com1 as the smaller connector.

Some of the motherboards had "keyed" motherboard connectors, so that it was impossible to get it in opposite. [my 1993 vintage 486 had keyed connectors]...but many boards aren't keyed. Many of the manuals are still available on the Internet, and you could try to snag a manual online & see which pin is #1 [this, too, might be marked in silkscreen on the motherboard = sometimes by a tiny "1", and sometimes a tiny white arrow pointing to the #1 pin]

A true serial mouse will have the best chance of working, although with the right adapter, A mouse designed to do both might be OK.

. . . and I thought Win95 was pretty speedy on my 486 when I upped its memory to 40mb (seemed like a ton back then)

[my puzzler this weekend has been a K6-2 350 box with either a power supply, motherboard, or memory problem - I'm close to ruling out the memory...] I love to work on the older boxes, as long as they don't take TOO long!
. . . Gary

[budbd]

The connectors seem to be able to be put in in either way, guess that means they aren't keyed. The motherboard is marked in various places of what is supposed to go there.
Haha, I haven't even ventured to put in the leds, suppose I will burn them out if put in wrong. There is one long line of pins that supposedly takes key lock, leds, turbo switch, reset switch etc, and it is confusing.

Yes, there is "silk screening" of what is supposed to generall go where.

Will look on the net to see any possible answers specific to my motherboard.

I am embarrassed to say that until early this year, I only had the same amount 32 mb of ram in my Gateway 333 mhz system that was my only computer as that old garage sale 486, I knew it was too little, but I was penny pinching till I bought a new system(eventually did upgrade the 333 as a backup computer).

This 486 machine is just full of slots, but only two memory slots, AND ISN'T AN AST AS I ORIGINALLY THOUGH BUT LOOKS JUST LIKE AN AST, JUST SOME OFF BRAND .
I am enthused about getting it going, but I feel that once I get the connection issue right, I should realize I need to get a copy of dos 6.22, not sure if I need windows on that, and I think the present windows 95 is corrupted slightly, needing to be wiped clean and reinstalled if really needed. Actually, I don't wanna even spend the money on a copy of windows 95.

[GaryRouth]

Once you have a motherboard manual handy (especially to help with connecting those case connectors - which might have enough markings for just the speaker, hd led, power, and reset - which might be all you need) - and you have all the connections and hardware set up OK, you might want to clean up & test that Win95 - it might be fine. It's already got the interface you're familiar with, and it's easy to work on. You'll just have to watch your free space on the disk. . . . RegClean 4.1 (available over at download.com) is a free MS Win95 Registry Cleaner & might come in handy on your 486 project . . .
. . . Gary

[budbd]

Thanks Gary

[budbd]

Of interest, I finally got my mouse to work by doing the longer and more thorough version of scandisk.
Unfortunately, for the life of me, I can't get the computer to read either the original 3 1/2 diskette or a brand new 3 1/2 diskette I have. Have switched the cable around on the drive and the motherboard.
Maybe it is just a windows 95 problem. darned computer claims it needs a fresh install of the video drivers as well. Actually, if it weren't for the 3 1/2 diskette problem, I would just erase the windows 95 and maybe later pick up a copy of it later.

I don't have a cd drive in this, and looks like I am gonna need one.
But really, this 3 1/2 diskette "not accessible" business has really stopped me, gonna have to really research the problem. Plus one of the memory cards aint getting read for its memory of 16 mb.

[GaryRouth]

Wild that the ScanDisk "thorough" restored your mouse driver. Even on a 650mb hard drive, chances that the mouse driver's area is on a repaired cluster is good for longshot money. Time to buy a Lottery ticket?

Since the serial cables weren't "keyed", I'm thinking it's a strong chance that your floppy cable isn't "keyed" either. Since there's no "key", it's possible to plug it in backwards on both the motherboard end and the drive end. At least one thing can be figured on: if it has a "twist" in the middle close to one end, that's the end that connects to the floppy drive. Other than that, happy juggling of cables. Isn't working on old systems fun?

You're having too much fun -
. . . and, Happy Fourth of July
. . . Gary

[budbd]

Yeah, it may have been indeed that I had switched cables, THEN did a thorough scan of the hard drive. Yeah, none of the cables are keyed.
I might have done more testing with the new 1.44 drive, and I think I might try switching cables again and even trying out the old 3 1/2 further.
The board I have was a powerful board when new, is at 100 mhz right now, and is a PVI-486SP3, with 3 pci, 1 vlb, and 3 EISA slots, of interest to note, and I found a a board layout diagram, and other info on the net.
The max amount of memory for this would be 2x64mb of ram, making 128 mb of ram.

I feel this was a powerful system motherboard for the time of 1993, heck, if my gateway 333mhz motherboard burned out, I could in theory use the eisa modem in the gateway, the gateway's hard drive(likely), even my windows 98, even the cd rom, and add 128 mb of used ram and still have a net capable machine as a backup.

[Colonel Sanders]

For the floppy, if the cable is wrong you'll see a "Floppy disk fail(40)"(or similar) error during the post. Check the BIOS and make sure it has a floppy of the right size in there. Unlike hard-drives and most IDE devices which can auto-detect (I wonder if a 486 can do that...) you will have to specify the floppy. Also if the cable lacks the twist near the end the floppy's at, it won't work (well, might work as B drive but I've never tried it). Another thing I've noticed, 90% of the time pin 1 on a floppy is towards the power connector (oddly enough, all IDE devices I've seen have the pin 1 on the opposite side).

As for RAM good luck finding 64MB sticks, they are pretty rare.

L J

[budbd]

PROBLEM SOLVED!

I found out that I needed to use the last connector on the cable with the connector on the motherboard the other way around.

Also, one of the 16 mg simms is not working for some reason. It sure would have been nice to have at least 32 mg ram, but maybe I might come across something locally or on the net.
Yeah, 64 mg simms were likely for servers, and would have to be 72 pinn, who knows, maybe ebay or just need to get another 16 mg chip stick.

[INR]

I love tearing apart/building old computers. Started out
same as you...experimenting with an old 486 and
(get this) an old 286 (OMG ! ran at ?! 25MHz )...just to
see what was inside
Since you already have most of your questions answered
in previous posts I'm a bit late finding this forum...
I do know where you can buy 72 pin simms cheap though!
Anandtech forums...forsale/fortrade and old processors, video cards etc.
I've been "teaching" myself on these old computers for the past year..maybe close to two..
Tear 'em down to the bare case, rebuild 'em..mix
and match parts from the other old computers..
You can add a new floppy drive, I even added a 32x cd-rom
drive to the 486...took out the 5 1/4 floppy drive and used that bay for the cd-rom drive.
My latest build was a Super Socket 7 K6-2 running 450MHz.
put 192MB SD ram in it, floppy, cd, usb to mobo headers..can use usb mouse, serial, parallel ports, 10/100 nic, put Win 98SE
on it and it runs like a race car on nitro ..LOL

[GaryRouth]

Since they're rare, those simms if found new are expensive. You can check on eBay for used modules - they might be worth a try if inexpensive enough (and if the seller has a good enough reputation).
. . . Gary

...sounds like you guys have more room for tinkering in your garages than I do

[budbd]

Thanks for the reply. I find these old computers are a learning tool. I have learned alot just in the last couple of days, learning about simm memory, such as knowing now to stay away from "EDO" memory for any 486, reading that my memory sockets on the 486 will accept 64 mb max in each socket, though I do wonder whether or not it is just a matter of that was all that was available at one time, cause I have seen on auction 128 mb x 2 =256 mb ram. Not that I really needed that much really.

Of course, I am having a few troubles mainly due to not having a cd drive in it, nor a win 95 disk.

[INR]

Not in the garage...I'm in the kitchen!
{ hubby said he wanted to see me in the kitchen
more often...... LOL...I don't think this was
exactly what he meant... :-D }

You can find used 72 pin simms on Anandtech
forums...for sale/for trade at VERY reasonable prices.
depending on size (MB), I've seen 72 pin simms sale for
$3 ...up to around $5 or so....
members will guarantee NON-DOA ...if the post does not
specify just ask...
You should at least go check it out....

[Pharaohwolf]

Sorry I did not find this thread earlier. I could have helped you pretty quick. What you have is an ASUS board and if you go to their website they still have support for this board. Manuals and drivers are available. Also as I suspected before I did my research for this there is a PS2 connection on that board along with a jumper to activate it. All you need is an add-on ps2 mouse port that will plug to the board. Check the plug configs though before you buy to make sure which plug it takes as there are two kinds that I know of. Also in all of my searches I have yet to ever find 64mb 72 pin simms. I have two 32mb 72 pin simms that it took me a year to find for one of my vintage machines. The 16mb chips are still plentiful. I buy all mine from the Kingston site. Windows 95 works great on them with the extra memory and you can even add up to a 2gb hard drive to increase the storage capacity if you can find one. I have rebuilt many of the 486 computers and even a few 386's. I have 12 licensed copies of the DOS 6.22 program and I could mail one to you for a small fee to cover shipping if you wanted to erase the Win95 OS. I would keep that OS if you could get it working though. It's a better and friendly OS and backwards compatable for all the 8 and 16 bit vintage programs too. If you want to really push the envelope with that machine you can buy an Overdrive processor from Kingston that simulates 133mhz. There is a jumper setting to set for that on this board too. Anyway just go to www.asus.com and link to the USA site, click the support link and do a search for PVI-486SP3. It will take you to the downloads you need. The download is a zip file and the manual is in pdf format so you will need Adobe Acrobat to read it after you open it with Winzip.

[budbd]

Thanks for that. In frustration this evening, I have decided that I am going to stop trying to make the 486 jump through loops. Though this is still a great learning experience.