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I just bought 2 486 motherboards. Have any opinions?

C

computerdude92

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Would anyone like to share with me their opinions on these boards or share any information? They look pretty good to me. Are they good boards? Has anyone here ever owned them before? I don't know anything about their chipsets. They are utilizing Socket 1 and Socket 2. So, being earlier 486 boards they would have trouble with drives larger than 528MB? Please tell me anything you know.

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Olivetti PCS30/PCS40 Combo 386/486 socket, possibly one of the first 486 boards ever made? "DOC: 11690" is marked on the PCB. Does this indicate it was manufactured in 1990? It has the VIA VT82C495/VT82C480 chipset.

http://motherboards.mbarron.net/models/486isa/pcs30-40.html

socket 1 486r.jpg



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Tekram G486UVP Socket 2, Is this one of the very first VLB boards? Still has the barrel battery, but includes an external batt connector.
It has the UMC UM82C481BF/UM82C482AF chipset.

I can't seem to find manuals on this second board right now.

486 socket 2 VLB.jpg

I notice the second board has about half of it's cache slots occupied. How well would the performance be with the small cache?
 
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computerdude92 said:
So, being earlier 486 boards they would have trouble with drives larger than 528MB?
Click to expand...


Likely. Most boards that were 486 and broke the INT13 limit were very late in the 486 era (1994/95). By that time P-Ones were becoming the dominant chips/boards. You still may be able to use an overlay or board to use larger drives.
 
The 1st mainboard was not made by Olivetti. But for low cost 486 PCs they used some taiwanese brand mainboards, I still remember there was one board made by MSI. But that's not the one, otherwise you woud find some printing MS-41xx between the ISA-slots.
 
What is the name of the cpu socket on the first board from 1990? It looks pretty weird for it to accept either a 386 or a 486. Which exact model cpus can I use? 5v or 3.3v versions? I've never seen anything like it.
 
It would be incredibly surprising (impossible) if that first board was made in 1990. Try looking at the date codes on the integrated circuits. They would probably lead to a manufacture date of 1993 or 1994.

You bought these on eBay? The pictures you posted are from there. Looking at the pictures on eBay I can see date codes of 1992 and the ISSI (RAM?) chips all have date codes from 1993. So there you go, it was probably made in 1993, or it could be from 1992 if the ISSI chips were added weeks or months after the board was made. That makes it far from being an early 486 board or even simply an old 486 board at all. No this is a recent/modern 486 board.

As said before by 1ST1 this board was not made by Olivetti but for a line of extremely crappy computers they called the PCS 30 and PCS 40. These were awful and cheap computers that had awful construction and build quality and that hurt the company's reputation which was previously known for expensive, quirky but (mostly) high-end PCs with great and serious construction and build quality. I think the PCS 30 and 40 were the first Olivetti PCs to not use an Olivetti-made motherboard and BIOS and mark the beginning of the downfall of the company and its increasingly-troubled state.

This does not mean that the board is crappy, and in fact being a simple generic Taiwanese motherboard it is probably less quirky than what Olivetti made hahaha. It should be as good as any other generic motherboard from the same time.

As the name 4386 implies this is a board that can work with a 386 or 486 CPU. Not gonna lie that is peculiar. The socket is to install a 486SX CPU or if your board has a 386 soldered (which yours doesn't) then it can be used to hold a 387 coprocessor, as indicated on the silkscreen. It will not accept a 386. So it looks like unless you solder a 386 to your board you are forced to use a 486SX with it.

The second board has date codes from 1993 so it was at least built that year. That does not make it one of the first board with VLB slots. I don't have any info on it but it looks like a good/decent board.
 
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If you're worried about hard drive size, there are IDE cards with their own BIOS extension (e.g. Promise) that can alleviate the problem. In other words, not a big deal.
 
If you want to build a 486 system, go with the second board. Tekram was a pretty good name, and the UMC 480 chipset was solid. It also has VLB slots, so you have better options for graphics adapter. Most importantly, it has a few 72-pin memory slots which makes it much easier to expand the memory beyond 8mb.

BTW, it looks like somebody robbed some of the cache from the Tekram board, as it is missing the tag RAM. Without the tag RAM, the remaining SRAM will not function.
It's normally better to have all 9 chips, as you can bank interleave for a small performance increase.
 
6885P5H said:
It would be incredibly surprising (impossible) if that first board was made in 1990. Try looking at the date codes on the integrated circuits. They would probably lead to a manufacture date of 1993 or 1994.

You bought these on eBay? The pictures you posted are from there. Looking at the pictures on eBay I can see date codes of 1992 and the ISSI (RAM?) chips all have date codes from 1993. So there you go, it was probably made in 1993, or it could be from 1992 if the ISSI chips were added weeks or months after the board was made. That makes it far from being an early 486 board or even simply an old 486 board at all. No this is a recent/modern 486 board.

As said before by 1ST1 this board was not made by Olivetti but for a line of extremely crappy computers they called the PCS 30 and PCS 40. These were awful and cheap computers that had awful construction and build quality and that hurt the company's reputation which was previously known for expensive, quirky but (mostly) high-end PCs with great and serious construction and build quality. I think the PCS 30 and 40 were the first Olivetti PCs to not use an Olivetti-made motherboard and BIOS and mark the beginning of the downfall of the company and its increasingly-troubled state.

This does not mean that the board is crappy, and in fact being a simple generic Taiwanese motherboard it is probably less quirky than what Olivetti made hahaha. It should be as good as any other generic motherboard from the same time.

As the name 4386 implies this is a board that can work with a 386 or 486 CPU. Not gonna lie that is peculiar. The socket is to install a 486SX CPU or if your board has a 386 soldered (which yours doesn't) then it can be used to hold a 387 coprocessor, as indicated on the silkscreen. It will not accept a 386. So it looks like unless you solder a 386 to your board you are forced to use a 486SX with it.

The second board has date codes from 1993 so it was at least built that year. That does not make it one of the first board with VLB slots. I don't have any info on it but it looks like a good/decent board.
Click to expand...

According to my research, the 486 was produced since late 1989, so why wouldn't actual systems built in 1990 or 1991 exist?

486SX? I couldn't possibly use a 486DX on mine? The website link I shared matches the model number of the board. And the manual on there claims it supports up to a DX2 66. The memory is only 30-pin simm, so would there be any bottlenecks if I use faster 486 cpus like the DX2 66? The manual also claims it does support a 386/25 to 386/40. What makes you believe it won't? Just asking.

I'm thinking to use this 1st board to build exactly what RWallmow built: A low-end generic 486. I was also thinking on using the same 486DX 33 on mine. I know for a fact that the DX includes a integrated FPU on the cpu itself. So that should definitely make up for the lack of co-prossesor FPU on this motherboard. I'll put in 8-32 megs of ram in mine with an OK-sized hard drive and try out Win 3.11 or even Windows 95 just for kicks. I have old educational games like Magic School Bus that require this exact same cpu speed. I'd love to see how well the games run on minimum requirements. The 90's was the best era for low end gamers. Earth Siege II, for example, needed a 486DX2 66 as the minimum cpu. It ran wonderful on my DX2 66 with Windows 95 and only 8 or 16 megs of ram!

By the way, how could you tell the pictures are from Ebay? I saved them to my PC and changed the filenames.
 
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RWallmow said:
That first one is a FIC 486-VC-HD board (Taiwanese), I have a DX-33 machine built around one, it's a pretty low-end board, pretty basic and slow, but it works (after I desoldered and modded the Dallas chip anyways)
View attachment 37335

http://th99.classic-computing.de/src/m/E-H/32521.htm
Click to expand...

Good specs on your version. But weren't those Trident 512K vga cards kinda crappy? No offense. I had 3 or so of them and they all had problems. All three cards would randomly switch between color and black & white display when powered on in a system. I couldn't find any jumpers on the card's PCB to fix the issue. Also, there are absolutely no drivers for Windows 95 and even having one of these cards in a Win95 system made it become very unstable. When I replaced it with a different video card, the problems went away.
 
That's interesting information, so it was built by FIC. This is a 4386-VC-HD though and not a 486-VC-HD. The 486-VC-HD was not built to be able to support a 386 and 387. You might say this is trivial information but I think it's worth pointing out.

So that strange tower is yours? I actually saved those pictures on my computer a while back because of how strange it is! I'm talking about the 5 1/4" floppy drive of course. It is so strange to see such an old and large floppy drive in a small and recent case like that!


486 systems built in 1989, 1990 and 1991 exist. But it is impossible for your board to have been made during those years since the integrated circuits that are soldered on it were built in 1992 (and the socketed ones 1993). Not to mention that it simply does not look like a 486 board from those years... Old and early 486 systems were mostly high-end and would typically have EISA slots, or be of large size, have a Weitek socket...

What makes me believe that it won't work with a 486DX? Uhmmm no I don't really remember why I said that. Try it... Or if you're talking about why I said that the socket won't accept a 386 it's because it simply won't. If a 386 even fits in there, I'm sure powering it on would be a disaster to the CPU, board or both. The only way to use a 386 CPU with this board is to solder one. Again, look at the silkscreen.

cpu.jpg
 
Hmm, I wonder why the manual claims it supports a 386... It could be the manual makes false claims... or the manual here refers to a different version of the board. Be my guest and take a look at it if you want.

Manual from the website:::::::::::

==View or Print jumper settings using Fixedsys or New Courier fonts==
PCS30/PCS40 386/486 Motherboard
- BIOS ID string ????????????? <--- please send yours in
- 8-30 pin SIMM slots (1-128meg FPM DRAM)
- 6-16bit ISA slots
- 64-256k cache support in 8-28pin sockets + 2 TAG RAM sockets
- AMI/Award Bios
- VIA VT82C495/VT82C481 Chipset
- OSC1 + OSC2 clock crystals
- DALLAS Real Time Clock
note: - Resistor Network Jumpers: RN50, RN51 + RN53 near cpu + cache
- NPU Options 80387DX
- Supports Intel 80487SX/80486SX/80486DX/DX2 or
Intel 80386DX,AMD80386DX at 25/33/40/50/66MHz
- Manufactured by: OLIVETTI
----------------------------------------------------------------------------
CONNECTIONS
----------------------------------------------------------------------------
Function Label Function Label
----------------------------------------------------------------------------
Turbo LED J5 Speaker J8
Turbo switch J6 Power LED + keylock J9
Reset switch J7
----------------------------------------------------------------------------
USER CONFIGURABLE SETTINGS
----------------------------------------------------------------------------
Function Label Position
----------------------------------------------------------------------------
*CMOS memory normal operation J1 Open
CMOS memory clear J1 Closed
*Monitor type select monochrome/EGA/VGA J2 Open
Monitor type select color J2 Closed
*NPU synchronous with CPU J40 pins 1 + 2
NPU asynchronous with CPU J40 pins 2 + 3
----------------------------------------------------------------------------
DRAM
----------------------------------------------------------------------------
Size Bank 0 Bank 1
----------------------------------------------------------------------------
4MB (4) 1M x 9 None
8MB (4) 1M x 9 (4) 1M x 9
16MB (4) 4M x 9 None
20MB (4) 1M x 9 (4) 4M x 9
32MB (4) 4M x 9 (4) 4M x 9
Note: The orientation of the banks is unidentified.
----------------------------------------------------------------------------
CACHE SIZE
----------------------------------------------------------------------------
Size Bank 0 Bank 1 M10 TAG
----------------------------------------------------------------------------
64KB (4) 8K x 8 (4) 8K x 8 (1) 8K x 8 (1) 8K x 8
128KB (4) 32K x 8 NONE (1) 8K x 8 (1) 8K x 8
256KB (4) 32K x 8 (4) 32K x 8 (1) 32K x 8 (1) 32K x 8
Note: M10 is optional and does not have to be installed.
----------------------------------------------------------------------------
CACHE JUMPER
----------------------------------------------------------------------------
size js1 js2 js3 js4
----------------------------------------------------------------------------
64KB pins 1 + 2 pins 1 + 2 pins 1 + 2 pins 1 + 2
128KB pins 1 + 2 pins 2 + 3 pins 2 + 3 pins 2 + 3
256KB pins 2 + 3 pins 2 + 3 pins 1 + 2 pins 1 + 2
----------------------------------------------------------------------------
CPU SPEED/TYPE
----------------------------------------------------------------------------
Setting JC1 JC2 JC3
----------------------------------------------------------------------------
80386SX-33 pins 1 + 2 pins 1 + 2 pins 1 + 2
80386DX-40 pins 1 + 2 pins 1 + 2 pins 1 + 2
80486SX-20 pins 2 + 3 pins 2 + 3 Open
80486SX-25 pins 2 + 3 pins 2 + 3 Open
80486SX-33 pins 2 + 3 pins 2 + 3 Open
80487SX-20 pins 1 + 2 pins 1 + 2 pins 2 + 3
80487SX-25 pins 1 + 2 pins 1 + 2 pins 2 + 3
80486DX-20 pins 1 + 2 pins 1 + 2 pins 1 + 2
80486DX-25 pins 1 + 2 pins 1 + 2 pins 1 + 2
80486DX-33 pins 1 + 2 pins 1 + 2 pins 1 + 2
80486DX-50 pins 1 + 2 pins 1 + 2 pins 1 + 2
80486DX2-50 pins 1 + 2 pins 1 + 2 pins 1 + 2
80486DX2-66 pins 1 + 2 pins 1 + 2 pins 1 + 2
----------------------------------------------------------------------------
CPU SPEED/TYPE (CON'T)
----------------------------------------------------------------------------
Setting JK1 JK2 JK3 JK4
----------------------------------------------------------------------------
80386SX-33 pins 1 + 2 pins 1 + 2 pins 1 + 2 pins 2 + 3
80386DX-40 pins 1 + 2 pins 1 + 2 pins 1 + 2 pins 2 + 3
80486SX-20 pins 1 + 2 pins 1 + 2 pins 2 + 3 pins 1 + 2
80486SX-25 pins 1 + 2 pins 1 + 2 pins 2 + 3 pins 1 + 2
80486SX-33 pins 2 + 3 pins 2 + 3 pins 2 + 3 pins 1 + 2
80487SX-20 pins 1 + 2 pins 1 + 2 pins 2 + 3 pins 1 + 2
80487SX-25 pins 1 + 2 pins 1 + 2 pins 2 + 3 pins 1 + 2
80486DX-20 pins 1 + 2 pins 1 + 2 pins 2 + 3 pins 1 + 2
80486DX-25 pins 1 + 2 pins 1 + 2 pins 2 + 3 pins 1 + 2
80486DX-33 pins 2 + 3 pins 2 + 3 pins 2 + 3 pins 1 + 2
80486DX-50 pins 2 + 3 pins 2 + 3 pins 2 + 3 pins 1 + 2
80486DX2-50 pins 1 + 2 pins 1 + 2 pins 2 + 3 pins 1 + 2
80486DX2-66 pins 2 + 3 pins 2 + 3 pins 2 + 3 pins 1 + 2
----------------------------------------------------------------------------
CPU SPEED/TYPE (CON'T)
----------------------------------------------------------------------------
Setting RN10 RN50 RN51 RN53
----------------------------------------------------------------------------
80386SX-33 Not installed nstalled Not installed Installed
80386DX-40 Not installed Installed Not installed Installed
80486SX-20 Installed Not installed Installed Not installed
80486SX-25 Installed Not installed Installed Not installed
80486SX-33 Installed Not installed Installed Not installed
80487SX-20 Installed Not installed Installed Not installed
80487SX-25 Installed Not installed Installed Not installed
80486DX-20 Installed Not installed Installed Not installed
80486DX-25 Installed Not installed Installed Not installed
80486DX-33 Installed Not installed Installed Not installed
80486DX-50 Installed Not installed Installed Not installed
80486DX2-50 Installed Not installed Installed Not installed
80486DX2-66 Installed Not installed Installed Not installed
=========================END OF DATA ON PCS30/PCS40==========================
 
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I don''t see any reason why a PCB couldn't be made in 1990 and populated in 1994 with chips made in 1992.

I'm not saying that I'm positive this board was made in 1990; I'm just saying that being populated with later chips does not mean someone waited until the chips were made to fabricate the PCB itself.
 
KC9UDX said:
So how do you know now?

Did you find a different manufacture date on the board?
Click to expand...

No, but I find it very unusual for various parts of the board to be made in various years. Tech was moving very fast in the 90's, so I doubt something in 1990 could be able to have the electrical requirements, pinouts, etc for chips made years later. I don't know for sure, considering the 486 came out before I was even born, but I feel more towards believing the idea that the board itself could be made around the dates of the actual chips on the board. That's all I can say.
 
6885P5H said:
This is a 4386-VC-HD though and not a 486-VC-HD. The 486-VC-HD was not built to be able to support a 386 and 387. You might say this is trivial information but I think it's worth pointing out.

View attachment 37351
Click to expand...

Aha.. So I missed that detail, (sorry I was sleepy ready these posts) So this now is making more sense. It's no wonder the manual I was reading up on was the wrong manual. The one I was referring to is for the version that has a soldered on 386DX CPU and 387DX FPU. My board does not have these areas soldered with chips.
 
6885P5H said:
"You bought these on eBay? The pictures you posted are from there. Looking at the pictures on eBay I can see date codes of 1992 and the ISSI (RAM?) chips all have date codes from 1993. So there you go, it was probably made in 1993, or it could be from 1992 if the ISSI chips were added weeks or months after the board was made. That makes it far from being an early 486 board or even simply an old 486 board at all. No this is a recent/modern 486 board."

"As the name 4386 implies this is a board that can work with a 386 or 486 CPU. Not gonna lie that is peculiar. The socket is to install a 486SX CPU or if your board has a 386 soldered (which yours doesn't) then it can be used to hold a 387 coprocessor, as indicated on the silkscreen. It will not accept a 386. So it looks like unless you solder a 386 to your board you are forced to use a 486SX with it.
Click to expand...

Yes, that makes sense. Though it probably could accept 486 processors up to at least a DX2 66.
 
Anonymous Coward said:
If you want to build a 486 system, go with the second board. Tekram was a pretty good name, and the UMC 480 chipset was solid. It also has VLB slots, so you have better options for graphics adapter. Most importantly, it has a few 72-pin memory slots which makes it much easier to expand the memory beyond 8mb.

BTW, it looks like somebody robbed some of the cache from the Tekram board, as it is missing the tag RAM. Without the tag RAM, the remaining SRAM will not function.
It's normally better to have all 9 chips, as you can bank interleave for a small performance increase.
Click to expand...

So how will this affect the amount of memory I can put in it? I don't know anything about 486 cache sockets. Is the board itself still usable in it's current state? I don't know how to replace the chips, as in I need to know which chips by individual part numbers I need to find first.
 
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