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Help (re)building a 486

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First post, by andre_6

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Hello everyone,

I got a 486 that I quite like the look of, and I want it to be an early DOS games until circa early/mid 90's gaming rig (I want to play the most DOS games possible at the correct speeds, let's say I imagine Doom to be the most advanced game I plan to play here). My idea is to replace the 340mb HDD for a 2GB one, install Win 3.1 and copy all my DOS Games at once from CD-ROM to the HDD. I want all games installed and readily available but within an HDD to keep it classic.

Can this configuration do that? Computer specs:

486-HC-HD VERTEX FIC motherboard
Intel 486DX-50
8mb of RAM 30 pin SIMM
no sound card
OAK TECHNOLOGY 77 TX2953526 16-BIT ISA VGA card
No CD-ROM (for now)

I never had a computer older than a Pentium Pro with Win95, so I would like to ask for your help in a few questions, for economy purposes I would like to keep the motherboard and go from there:

1. Should I upgrade the CPU to a DX-66 or would that be too fast for earlier DOS games? What improvements can or should I do for the graphics card and getting a sound card? Should I upgrade the 8MB RAM, if so to what value?

2. My motherboard only has a DIN port for keyboard and DB-9 mouse interface through an expansion interface board. I have an early PS/2 IBM mouse and keyboard that I want to use here, how would I go about to do that?

I'm still learning from you all in this forum but with your input I'll get there, thank you so much for your attention and replies!

Last edited by andre_6 on 2022-09-10, 16:14. Edited 2 times in total.

Reply 1 of 140, by melbar

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andre_6 wrote on 2021-04-30, 23:06:

1. Should I upgrade the CPU to a DX-66 or would that be too fast for earlier DOS games? What improvements can or should I do for the graphics card and getting a sound card? Should I upgrade the 8MB RAM, if so to what value?

What VGA card do you want to use?
What VGA bus you want to use? ISA, VL-bus , PCI ?

Considering fast VGA cards (e.g. TSENG , S3 , Cirrus-Logic) you will see frame rates for DOOM, (stated on excel file acc. to vogons user:
https://docs.google.com/spreadsheets/d/1uKhCI … #gid=1720967797
)

DX2-66 (PCI VGA card, TSENG , S3): ~ 25fps
DX2-66 (VL-bus, Cirrus-Logic) : ~ 24fps
DX-50 (ISA VGA card, ATI Mach32) : ~ 18fps

For DOOM, a 486-DX4 or pentium system would be much better.

#1 K6-2/500, #2 Athlon1200, #3 Celeron1000A, #4 A64-3700, #5 P4HT-3200, #6 P4-2800, #7 Am486DX2-66

Reply 2 of 140, by mcyt

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andre_6 wrote on 2021-04-30, 23:06:
486-HC-HD VERTEX (?) motherboard Intel 486DX-50 8mb of RAM no sound card OAK TECHNOLOGY TX2953526 1991 16-BIT ISA VGA card No CD […]
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486-HC-HD VERTEX (?) motherboard
Intel 486DX-50
8mb of RAM
no sound card
OAK TECHNOLOGY TX2953526 1991 16-BIT ISA VGA card
No CD-ROM (for now)

1. Should I upgrade the CPU to a DX-66 or would that be too fast for earlier DOS games? What improvements can or should I do for the graphics card and getting a sound card? Should I upgrade the 8MB RAM, if so to what value?

There's not going to be a huge difference in performance between 50 and 66 mhz, so I'd say go for the 66 if the price isn't an issue and the motherboard supports it. Most 486-era games ran too slow in my experience. Games were outpacing the hardware at that time.

For the sound card, there are quite a few options, but I'd just look for whatever's the cheapest SoundBlaster Pro or 16 that you can get. That's unless you want something specific, but it doesn't sound like you do. The SB cards were pretty universally supported and while some of the different models have their pros and cons, they all work pretty well in my experience. (I have one of the "not perfect" SB16's; I've never had a problem with it.)

You're probably going to want to upgrade the graphics, but hey, try it out and see first. I think it's going to be pretty slow running something like Doom, though. I have an S3 Virge-based card in my 486/Pentium system, but this might be a little late for what you're trying to model. This is a good place to start if you want to see what'll even run some popular games properly: https://gona.mactar.hu/DOS_TESTS/

If your system *only* has ISA (would probably be a very early 486 in that case), then I'm not sure, but check out this post: 14 ISA and VLB graphics cards on a 486DX2 66

2. My motherboard only has a DIN port for keyboard and DB-9 mouse interface through an expansion interface board. I have an early PS/2 IBM mouse and keyboard that I want to use here, how would I go about to do that?

Make sure your motherboard really doesn't have any PS2 headers on it. It seems weird to me that a 486 board wouldn't. You might just need something like this: https://www.ebay.com/itm/PS-2-Mini-Din-6Pin-F … 42848851?_ul=IN

Reply 3 of 140, by kdr

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andre_6 wrote on 2021-04-30, 23:06:

2. My motherboard only has a DIN port for keyboard and DB-9 mouse interface through an expansion interface board. I have an early PS/2 IBM mouse and keyboard that I want to use here, how would I go about to do that?

You can use a PS/2 keyboard with your motherboard, it just requires an adapter cable to change the 6-pin mini DIN to a 5-pin DIN. These used to be really common, and I still find them lying around from time to time, hopefully you can find one locally at the usual suspects (thrift stores, e-waste recyclers, etc.)

Reply 5 of 140, by andre_6

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Thank you for your replies, I'll try to answer to all the points you mentioned.

I am not looking for anything specific, just some orientation into improving on what I already have. I can give up on Doom and its era for example, as long as I can play earlier DOS games at a nice and correct speed. So if I prioritise that, would I still need the DX-66 and a new graphics card? I know these things are always vague, I'm just trying to get the best idea I can before buying components and reassembling. Also, is the 8MB RAM ok for that?

Deksor wrote on 2021-05-01, 13:10:

That was the closest I was able to find, yes, mine says "486-HC-HD" on it, instead of "486-VC-HD". But it looks like the one I have, so ISA VGA is my only option I assume.

kdr wrote on 2021-05-01, 11:01:

You can use a PS/2 keyboard with your motherboard, it just requires an adapter cable to change the 6-pin mini DIN to a 5-pin DIN. These used to be really common, and I still find them lying around from time to time, hopefully you can find one locally at the usual suspects (thrift stores, e-waste recyclers, etc.)

mcyt wrote on 2021-05-01, 08:48:

Make sure your motherboard really doesn't have any PS2 headers on it. It seems weird to me that a 486 board wouldn't. You might just need something like this: https://www.ebay.com/itm/PS-2-Mini-Din-6Pin-F … 42848851?_ul=IN

It doesn't have PS/2 headers, so from your suggestions how would I connect both my IBM early PS/2 mouse and keyboard? Use that adapter cable for the keyboard and another solution for the PS/2 mouse? How would I connect that Ebay Header Adapter for the mouse?

My monitor says "October 1992" and it was sold as a set with this computer, if it helps in any way. Thank you all!

Reply 6 of 140, by megatron-uk

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andre_6 wrote on 2021-05-01, 14:00:

It doesn't have PS/2 headers, so from your suggestions how would I connect both my IBM early PS/2 mouse and keyboard? Use that adapter cable for the keyboard and another solution for the PS/2 mouse? How would I connect that Ebay Header Adapter for the mouse?

My monitor says "October 1992" and it was sold as a set with this computer, if it helps in any way. Thank you all!

For keyboard; yes - just use a common, cheap mini-din to PS/2 keyboard adaptor:

https://www.amazon.co.uk/Cable-Core-Mini-Fema … 19883189&sr=8-3

https://www.amazon.co.uk/Adapter-Female-Adapt … 19883189&sr=8-4

For PS/2 mouse, well, that's a bit more difficult. Your motherboard *may* have a hidden PS/2 connector unpopulated on the board, or it may be possible to add the functionality from one of the supporting chips... but unless you're very, very lucky you're quite likely not going to be able to - PS/2 mouse support on non-IBM 486 motherboards just wasn't a thing until very, very late, and even then didn't become widespread.

You'll either have to find a dual protocol serial/ps2 mouse (which are pretty rare these days), or invest in a serial to PS/2 mouse adapter like one of these:

8BIT ISA SERIAL I/O TO PS2 MOUSE

PS/2 to Microsoft Serialmouse Adapter Converter / Updated First Post / Firmware Update added

My collection database and technical wiki:
https://www.target-earth.net

Reply 7 of 140, by Deksor

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andre_6 wrote on 2021-05-01, 14:00:

That was the closest I was able to find, yes, mine says "486-HC-HD" on it, instead of "486-VC-HD". But it looks like the one I have, so ISA VGA is my only option I assume.

Can you please send a photo (if possible, a clear one in case we have to add it to the database) ? I'm curious to know if it's a board we haven't documented yet.

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 8 of 140, by andre_6

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megatron-uk wrote on 2021-05-01, 15:36:
For keyboard; yes - just use a common, cheap mini-din to PS/2 keyboard adaptor: […]
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For keyboard; yes - just use a common, cheap mini-din to PS/2 keyboard adaptor:

https://www.amazon.co.uk/Cable-Core-Mini-Fema … 19883189&sr=8-3

https://www.amazon.co.uk/Adapter-Female-Adapt … 19883189&sr=8-4

For PS/2 mouse, well, that's a bit more difficult. Your motherboard *may* have a hidden PS/2 connector unpopulated on the board, or it may be possible to add the functionality from one of the supporting chips... but unless you're very, very lucky you're quite likely not going to be able to - PS/2 mouse support on non-IBM 486 motherboards just wasn't a thing until very, very late, and even then didn't become widespread.

You'll either have to find a dual protocol serial/ps2 mouse (which are pretty rare these days), or invest in a serial to PS/2 mouse adapter like one of these:

8BIT ISA SERIAL I/O TO PS2 MOUSE

PS/2 to Microsoft Serialmouse Adapter Converter / Updated First Post / Firmware Update added

I see, thanks, I'll look into it. If I can use my IBM Ps/2 keyboard with the adapter that will keep me happy for now.

Deksor wrote on 2021-05-01, 17:29:

Can you please send a photo (if possible, a clear one in case we have to add it to the database) ? I'm curious to know if it's a board we haven't documented yet.

It's hard to get the lighting right where I am now, but take a look.

So even if it doesn't run Doom as it should, will the DX-50 / 8MB RAM / OAK TECHNOLOGY TX2953526 1991 16-BIT ISA VGA card combo be enough for earlier DOS games? If so I will keep it for now and upgrade to a DX-66 and a better ISA graphics card when a good deal comes by

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Reply 9 of 140, by Deksor

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Thanks for the photo !
It really is the same board, that's so strange, why give two names for litterally the same thing ? 🤣

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 10 of 140, by andre_6

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Deksor wrote on 2021-05-02, 15:40:

Thanks for the photo !
It really is the same board, that's so strange, why give two names for litterally the same thing ? 🤣

I have no idea, if you guys don't know then it's anyone's guess...

andre_6 wrote on 2021-05-02, 15:28:

So even if it doesn't run Doom as it should, will the DX-50 / 8MB RAM / OAK TECHNOLOGY TX2953526 1991 16-BIT ISA VGA card combo be enough for earlier DOS games? If so I will keep this configuration for now and upgrade to a DX-66 and a better ISA graphics card when a good deal comes by

Could you please give me some pointers regarding my question? The cleaning and restoration is going along, with that info I think I'm all set to proceed

Reply 11 of 140, by andre_6

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Looking at the board while disassembling, I noticed that one of the two floppy disk drives was not connected. Then looking at these photos, I realise I don't have enough connections.

I would like to connect the two original floppy drives, and to install a CD-ROM drive in there too. Do I need another expansion board like this one?

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Reply 12 of 140, by majestyk

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Yes there are differences between FIC´s "486 VC-HD" and "486 HC-HD".
On the VC-HD you can install either an additional numeric processor besides the onboard CPU or a different CPU in the same 86/87 socket. There´s also a socket for a second oscillator if CPU and NPU are supposed to run at different frequencies.

FIC_4386-VC-HD.jpg
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The HC-HD has either an onboard CPU OR this space is unpopulated and you can install your own CPU. It´s a completely different concept.

Reply 13 of 140, by evasive

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4386-VC-HD is DOC: 11690
which is different from the two others

486-VC-HD is DOC: 11670
486-HC-HD is DOC: 11670
they even have the same DOC number, that means they are identical. Except for the name. This may be a rare typing error for the silk-screen labeling machine or it may be an OEM board such as used by Vobis/Highscreen computers (they were using FIC boards in some of their builds). This information may be lost to time...

Reply 14 of 140, by megatron-uk

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andre_6 wrote on 2021-05-03, 00:41:

Looking at the board while disassembling, I noticed that one of the two floppy disk drives was not connected. Then looking at these photos, I realise I don't have enough connections.

I would like to connect the two original floppy drives, and to install a CD-ROM drive in there too. Do I need another expansion board like this one?

No. You don't need another FDD/HDD controller.

You can (and should) connect two floppy drives on a single cable. They should have 3 connectors on the cable, like this:

floppy-drive-cable.jpg
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A (IDE/ATAPI) CD-ROM drive connects to the same cable as your (IDE) hard drive - ideally your disk controller card will have two IDE connections on it (it's better for performance to have CD-ROM and hard drive on different cables, but not essential).

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https://www.target-earth.net

Reply 15 of 140, by majestyk

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ESCOM also used special (crippled) FIC mainboards like the "486 VIP-IO" without the VLB slots, which correctly must have been called "486 IP-IO".
I would not be surprised if companies like ESCOM, VOBIS bought differently (wrong) labeled mainboards just so save a few $$.

Reply 16 of 140, by andre_6

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megatron-uk wrote on 2021-05-03, 08:07:
No. You don't need another FDD/HDD controller. […]
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andre_6 wrote on 2021-05-03, 00:41:

Looking at the board while disassembling, I noticed that one of the two floppy disk drives was not connected. Then looking at these photos, I realise I don't have enough connections.

I would like to connect the two original floppy drives, and to install a CD-ROM drive in there too. Do I need another expansion board like this one?

No. You don't need another FDD/HDD controller.

You can (and should) connect two floppy drives on a single cable. They should have 3 connectors on the cable, like this:

floppy-drive-cable.jpg

A (IDE/ATAPI) CD-ROM drive connects to the same cable as your (IDE) hard drive - ideally your disk controller card will have two IDE connections on it (it's better for performance to have CD-ROM and hard drive on different cables, but not essential).

Thank you so much, I never dealt with 486s, I was so focused on the ISA controller board that I didn't even think that I could simply do that... like any other "newer" pc!

Reply 17 of 140, by chinny22

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Think your more or less all set 😀

Re the mouse, Easiest option is going to get a serial mouse. They aren't great, but at least on a 486 your not using a mouse too often.

Sound card, While I'm a fan of SoundBlaster even with all their issues I wouldn't limit myself to just Creative.
ESS AudioDrive and Yamaha YMF cards are also fairly common and highly regarded if you can get them for a better deal.

CD-Drive,
As Megatron-UK said, much like the Disk drive you can use the same cable for both HDD/CD drive. You just need to set the jumper as primary on the HDD and Slave for the CD drive.
Some soundcards came with a IDE header for CD drives so that could be an option depending on what you get. But I wouldn't stress about having both on the same cable too much.

I think using the CPU/video card you have now and simply waiting is a good idea. Earlier games will be fine and even games like doom will be playable.

Reply 18 of 140, by andre_6

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chinny22 wrote on 2021-05-05, 10:00:
Think your more or less all set :) […]
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Think your more or less all set 😀

Re the mouse, Easiest option is going to get a serial mouse. They aren't great, but at least on a 486 your not using a mouse too often.

Sound card, While I'm a fan of SoundBlaster even with all their issues I wouldn't limit myself to just Creative.
ESS AudioDrive and Yamaha YMF cards are also fairly common and highly regarded if you can get them for a better deal.

CD-Drive,
As Megatron-UK said, much like the Disk drive you can use the same cable for both HDD/CD drive. You just need to set the jumper as primary on the HDD and Slave for the CD drive.
Some soundcards came with a IDE header for CD drives so that could be an option depending on what you get. But I wouldn't stress about having both on the same cable too much.

I think using the CPU/video card you have now and simply waiting is a good idea. Earlier games will be fine and even games like doom will be playable.

Thank you for the input, still some things to iron out, but now that you guys pointed me out to my motherboard's specs I know it can support a DX-2 66, so I will go for that and for the upgrade from 8MB to 16MB RAM, and then see how things run. I got a very cheap Vibra 16 CT4180, so I should be all set in that regard. I have a 4GB HDD, can I install it normally for use in DOS 6.22 and Win 3.1? I assume it will just recognize it as 2GB, and that would be fine by me.

Right now I have to deal with the flat (and somewhat crowded as you can see from the mobo's photo) DS1287 Dallas Chip. I have a friend who deals with audio equipment and has experience, he says that it might take a long time to de-solder the chip to do an external battery fix, he'll try with his tools he uses for audio boards but he's not sure that he can do it. It seems like it's easy enough for all you guys, what tools / procedures do you use for that?

The original case came with two 3,5" floppy drives, I was thinking of adding a 5,25" drive but all IDE's will be taken between the two 3,5", the CD-ROM and the HDD...

Reply 19 of 140, by chinny22

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I'm sure someone will mention the CT4180 has a CQM rather then true OPL chip but that "drawback" is overblown if you ask me and Vibra should be just fine, No ISA card is perfect after all.

First off test to see if the full 4GB HDD is recognised in BIOS, some motherboards max out at 500MB. no big deal if it does both hardware and software workarounds exist.
You'll need to fdisk the hard drive, as long as you use the one that comes with dos, it'll limit you to Fat16, It'll also let you create a extended partition to use the remaining 2GB if you wanted.

If your friend is any good at soldering you can simply replace the battery with a socket which should be easy enough. You can then simply replace the Dallas chip when needed, or hack a Dallas chip
https://www.classic-computers.org.nz/blog/200 … attery-chip.htm

Floppy drives aren't IDE devices and its rare for floppy controllers to support more then 2 drives. I doubt you'll use a 5.25 drive much anyway. No harm in having it in the case not hooked up if your just after the look though, just don't tell anyone 😉