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DistantStar001

Just got a 484, and I have questions

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So I was recently given an off brand 486 (PC? IBM Clone?).  I'm not an expert on these, and as a child, always had a less than friendly relationship with DOS based computers.  Honestly, it wasn't until Windows 10 came out that my PC karma began to improve.  In any case, the setup is as follows:  486 processor (obviously) 66MHz DX2, with an unoccupied spot marked for a 386.  Approximately 2MB of RAM (640K base, 15616 Extended)  Two floppy drives, one 3.5in in drive B (but I don't know if it's a 720k or 1.44MB.  I know it says it's 1.44MB, but that's just because I said it was in the BIOS setup and the machine didn't argue with me), and a 5.25in 1.2 MB in drive A.  There is also a CD-ROM, and Hard-drive in drive D (I think, or that could be the CD-ROM).

 

The pictures are of the boot screen and the (I'm guessing) DOS screen after setting up BIOS.  

Boot.thumb.jpg.ec2faf0a3eed6bbaff27c6e8a4e29818.jpgDOS.thumb.jpg.794b7a1c25f014f7e2bcc17efad86472.jpg

 

However, whatever battery that powers the BIOS memory is dead, as I have to reconfigure the setup every time I turn it on.  The pictures above represent as far as I've gotten this thing to boot to since I don't currently have a boot disk, and I honestly have no idea what version of DOS is on it in any case. Which beings me to my first question: Is there any way to figure out what version of DOS I have without a boot disk?  Also is it possible to use a 3.5in boot disk even though the 3.5in is in drive B?  Can I change this in setup or do I need to physically rewire the drives?

 

Ultimately, I have three goals for this machine.  The first is to have something that can write disks for my TRS-80 Model III.  I already know that I'm going to need a 360k floppy drive for that.  The second is to be able to finally play Star Trek 25th Anniversary (I've had a boxed copy on 5.25in for years, but never had a compatible computer.  Still not sure if I do, as the box says Tandy 1000 compatibility is required).  And third, is to load Microsoft entertainment pack, and Chip's Challenge!

 

So my second question is: Are any of these goals achievable with this computer?

 

That's it for now, and as always, any help is appreciated.  🙂

 

 

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9 minutes ago, DistantStar001 said:

So I was recently given an off brand 486 (PC? IBM Clone?).  I'm not an expert on these, and as a child, always had a less than friendly relationship with DOS based computers.  Honestly, it wasn't until Windows 10 came out that my PC karma began to improve.  In any case, the setup is as follows:  486 processor (obviously) 66MHz DX2, with an unoccupied spot marked for a 386.  Approximately 2MB of RAM (640K base, 15616 Extended)  Two floppy drives, one 3.5in in drive B (but I don't know if it's a 720k or 1.44MB.  I know it says it's 1.44MB, but that's just because I said it was in the BIOS setup and the machine didn't argue with me), and a 5.25in 1.2 MB in drive A.  There is also a CD-ROM, and Hard-drive in drive D (I think, or that could be the CD-ROM).

 

The pictures are of the boot screen and the (I'm guessing) DOS screen after setting up BIOS.  

Boot.thumb.jpg.ec2faf0a3eed6bbaff27c6e8a4e29818.jpgDOS.thumb.jpg.794b7a1c25f014f7e2bcc17efad86472.jpg

 

However, whatever battery that powers the BIOS memory is dead, as I have to reconfigure the setup every time I turn it on.  The pictures above represent as far as I've gotten this thing to boot to since I don't currently have a boot disk, and I honestly have no idea what version of DOS is on it in any case. Which beings me to my first question: Is there any way to figure out what version of DOS I have without a boot disk?  Also is it possible to use a 3.5in boot disk even though the 3.5in is in drive B?  Can I change this in setup or do I need to physically rewire the drives?

 

Ultimately, I have three goals for this machine.  The first is to have something that can write disks for my TRS-80 Model III.  I already know that I'm going to need a 360k floppy drive for that.  The second is to be able to finally play Star Trek 25th Anniversary (I've had a boxed copy on 5.25in for years, but never had a compatible computer.  Still not sure if I do, as the box says Tandy 1000 compatibility is required).  And third, is to load Microsoft entertainment pack, and Chip's Challenge!

 

So my second question is: Are any of these goals achievable with this computer?

 

That's it for now, and as always, any help is appreciated.  🙂

 

 

I thought ST 25ANIV was VGA, not Tandy?

 

Most of what you want should be easy enough, I don't think any of that software should be incapable of running on a 486.

 

I think the easiest way to deal with the boot disks is, well, swap the drives on the cable.

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13 minutes ago, The Usotsuki said:

I thought ST 25ANIV was VGA, not Tandy?

I think you're right, as this is hooked up to a VGA monitor.  I honestly know next to nothing about MS-DOS.  The only reason I knew that I needed a boot disk at all is remembering how my mother booted her old Packard-Bell.  When I first got this, all it would say after setup was that there was no operating system found.  It's literally taken me weeks to get it to ask for a boot disk.  

I'm guessing that I won't have to keep setting it up once I replace the battery.

17 minutes ago, The Usotsuki said:

I think the easiest way to deal with the boot disks is, well, swap the drives on the cable.

There's still a chance that I might be able to get one on 5.25in, but if I can't, this is really good to know.  Thanks!

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You're gonna wanna fix that CMOS battery. Gets old real fast always fixing those settings.

 

Just clean up the crap from the old one and solder or "connector-in" an AA holder with AA batteries.

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Posted (edited)

Just looking at the shots it appears you either have no hard drive or a dead hard drive. So, it has no DOS :) The message you are seeing is being generated from the BIOS telling you it cannot find a boot disk and to insert a system disk essentially.

 

Can you provide high resolution pictures of the inside? If the CMOS battery is an old leak-able/exploding type you are going to want to get that out right away. Even if it is a coin cell, get it out and replace it. For the first time in my decades of computer repair I came across a machine recently with an exploded CR2032....crazy....and it corroded some of the board (but thankfully functions fine as I apparently caught it just in time).

 

This 486 has 16MB of memory which is nice. This is the machine I would have loved back in the day. When these were available all I had was a 386 16MHz with 4MB of memory ;)

Edited by eightbit

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The only safe battery is an off-board battery. Did that to my vintage 486.

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For archival purposes, this thread is worthless. Joke in there regarding the platform, but anyway...

 

Urge you to edit the title to read 486. No such thing as a "484".

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4 minutes ago, save2600 said:

For archival purposes, this thread is worthless. Joke in there regarding the platform, but anyway...

 

Urge you to edit the title to read 486. No such thing as a "484".

 

I agree with this. I didn't mention it as I knew what the thread starter "meant", but adjusting the thread title to correct this should certainly be done.

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2 hours ago, save2600 said:

For archival purposes, this thread is worthless. Joke in there regarding the platform, but anyway...

 

Urge you to edit the title to read 486. No such thing as a "484".

 

1 hour ago, eightbit said:

 

I agree with this. I didn't mention it as I knew what the thread starter "meant", but adjusting the thread title to correct this should certainly be done.

Just noticed that!  Sorry for the typo.  How do I fix it?

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4 hours ago, eightbit said:

Just looking at the shots it appears you either have no hard drive or a dead hard drive. So, it has no DOS :) The message you are seeing is being generated from the BIOS telling you it cannot find a boot disk and to insert a system disk essentially.

I can verify that there is indeed a hard drive installed, and that it seems to spin up.  However, I don't know if it was wiped before I got it.

4 hours ago, eightbit said:

Can you provide high resolution pictures of the inside? If the CMOS battery is an old leak-able/exploding type you are going to want to get that out right away. Even if it is a coin cell, get it out and replace it. For the first time in my decades of computer repair I came across a machine recently with an exploded CR2032....crazy....and it corroded some of the board (but thankfully functions fine as I apparently caught it just in time).

IMG_2126.thumb.jpeg.0b50c33483df004e627a6e60968b4969.jpeg

Sorry.  This is about as hi-res as my iPad will allow.  The good news is that it's not on the board!  :-)

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Your board could still have a battery onboard. Most 486s of the era had an external + onboard battery. double check that.

 

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Posted (edited)

The photo from Phil's does not show such a thing.

 

1972109_orig.jpg

 

I dont see a Dallas RTC either.

 

Looks like one that was designed to use external battery pack exclusively, so the port is probably designed to charge.

 

 

 

Still waiting on positive ID from the OP.

 

 

Edited by wierd_w

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17 minutes ago, wierd_w said:

The photo from Phil's does not show such a thing.

 

1972109_orig.jpg

 

I dont see a Dallas RTC either.

 

Looks like one that was designed to use external battery pack exclusively, so the port is probably designed to charge.

 

 

 

Still waiting on positive ID from the OP.

 

 

That seems to be my board, marked FX-3000 Rev 1.0.  Although only one of the sockets (the lowest outer one) in the upper right corner is populated.  

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Posted (edited)

That the battery in the pic has a date, and is labeled "high energy" and "do not charge" tells me it's a primary cell only.

 

Yes - here - https://batteryguy.com/lintronics+tl5242p-replacement-battery.html

 

I'm not familiar with any 486 mainboards that charge their external batteries. But then again I haven't seen every make and model.

 

The board above looks like it has the diodes and two transistors. But no resistors for charge current limiting.

Edited by Keatah

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Posted (edited)

Interesting-- well, at least we have positive ID on the model, and can see that it does not have onboard corrosion landmine, so that's good.

 

Looks like he just needs a new battery. 

 

If he gives me pictures of his multi-IO, I can see if I can ID that too.

 

 

From his statement (Lowest, outermost socket in upper right corner populated, all others vacant) sounds like it is not carrying the full compliment of L2 cache.  He might benefit from ordering some SRAM modules to stuff in there.

Edited by wierd_w

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3 minutes ago, wierd_w said:

If he gives me pictures of his multi-IO, I can see if I can ID that too.

I have no idea what that is.  Maybe one of the cards?  Sorry, my only experience with these is crashing them as a kid.  It got so bad that I didn't even have to touch them.  I'd just look at one and it would crash in front of me.  

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Posted (edited)
16 minutes ago, DistantStar001 said:

I have no idea what that is.  Maybe one of the cards?  Sorry, my only experience with these is crashing them as a kid.  It got so bad that I didn't even have to touch them.  I'd just look at one and it would crash in front of me.  

The thing that has the floppy diskette drives, CDrom, and hard drive plugged into it.

 

The term is "multi IO card", because usually they also have serial ports, parallel port, game port, and such on them too.  If I can positively identify the card, I can get you some limited documentation on how to configure it.

 

 

Further digging--

 

The video bios ID string suggests it is an Oak Technologies Inc VGA card-- most hits for that bios ID suggest it is an OTI-037C.

Does it look like this?

438_oak_oti037c_ab043255_top_hq.jpg

 

If so, I can see about getting data on the jumper settings.

Edited by wierd_w

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Posted (edited)
24 minutes ago, wierd_w said:

The thing that has the floppy diskette drives, CDrom, and hard drive plugged into it.

 

The term is "multi IO card", because usually they also have serial ports, parallel port, game port, and such on them too.  If I can positively identify the card, I can get you some limited documentation on how to configure it.

image.thumb.png.a8426581a70bdab6bd99d6e32fece0a2.png

This is the card that the floppies and hard drive are plugged into.  There are no external ports on this, and the CD-ROM seems to be connected to a sound card.

image.thumb.png.0390e926c9f9340685e74d0d674e05c2.png

 

There is a male D-9 port attached to this card, which I'm assuming is the serial port, as well as a male D-25 that I'm guessing is parallel?

 

There is also a female D-9 on the video card.

Edited by DistantStar001
Additional information.

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4 hours ago, DistantStar001 said:

 

Just noticed that!  Sorry for the typo.  How do I fix it?

Is there not an option to edit in the bottom left of your first post? Should read:

 

+ Quote Edit

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It could be a matter of assigning a hard drive in the setup to get this thing to boot.  If it doesn't autodetect the hard drive the parameters should be on the label of the drive.  Did 486 computers typically autodetect hard drives?

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Some had options to do that. Others did not, and required you to put either one of the standard types, or type 47. (user type).

 

 

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