-

Love those dual gold-tops! Must get HOT!

It's probably not as hot as you think. I believe those CPUs are 15W each, and can get by with just a heatsink. People made a big deal about the heat when the Pentium came out, but it was really just hot compared to a 486. Modern CPUs are complete pigs compared to the P60.

Interesting! I fired up my Gateway 2000 P5-60 and I think you're right. It's got a passive heatsink and really is only warm to the touch after an hour of gaming.

Heh, I was messing with my Packard Bell Legend 300CD earlier and the CPU really doesn't get that warm, for it only having a passive heatsink. Though to be fair, there is also a case fan also cooling it.

Do you have any docs/ manuals for that Acer J3 board? I've got the same board but with a 486 module instead, which incidentally looks like a precursor to Slot 1 CPU cartridges.

When I get some time, I'll be looking to build my first EISA system. This era passed me by very quickly, and I ended up building PCI systems because it was going to be the next standard. Justified in hindsight, as PCI has lasted around 20 years or so. I remember EISA being a big deal back in the day, especially when reading Byte magazine.

I'm trying to ascertain whether this board needs some kind of special power supply with the extra connector in the main picture?... Also, I can't figure out whether this board has a Turbo header or not... there seems to be a jumper block "J5" that looks unlabelled? Not a big deal if it doesn't. Any info to get this great looking board up and running would be appreciated. Thanks in advance.

I do have some documents, but I think they are not 100% complete. Have you seen UKT Support:

http://www.uktsupport.co.uk/acer/mb/j3.htm

They have some jumpers listed. I think I found a second website as well, but I'll have to check my notes. I don't think I found a proper explanation for the front panel connectors, so I had to do some guesswork to get the reset and power LED in the right places. My case does not have a turbo button, so I didn't explore a possible jumper location, but it's possible it's not supported.

The extra power connector seems to be optional. I'm not using it and everything seems to be okay. It's probably not needed unless you're running 8 full length EISA cards.

Check my old posting for EISA CFG files:

http://www.vintage-computer.com/vcforum/archi … hp/t-35167.html

http://bbs.actapricot.org/files/area41/eisacfg.exe

There's even a TH99 entry:

http://museum.ttrk.ee/th99/m/A-B/32504.htm

Unfortunately it doesn't help us much with power, turbo and reset pin positions. At the very least I am sure reset is contained in the J5 block. I discovered this by randomly probing around. I was also able to get my power LED light going on J5 as well, but I am not 100% sure it's in the correct position. It could be the turbo LED for all I know. With a multimeter you can at least figure out which pins are power and which are ground. Turbo LED and switch pins (if present) are probably traceable back to the BIOS pins. The original Acer Power 9000 case seems to have a turbo LED on it, but the picture is not clear enough to see if a turbo switch is present. It's possible the turbo function was controlled entirely through key combinations.

Nice one! Cheers for all the links, some of them I had already stumbled upon, and one of them has helped me eliminate jumper block "J7". Here's another TH99 link with slightly different but complementary info:

http://museum.ttrk.ee/th99/m/A-B/32293.htm

... However, no mention of a Floppy drive header in any of the aforementioned links, especially the above link where all sorts of other headers are labelled, which makes me think there are revisions to this board with, and without, this header. I found a PDF manual for this board mentioning this header:

Also In this manual, I couldn't find reference to J5 and J7 blocks, but thanks to one of your links above, I've found out they are for SCSI LED and optional mouse/ keyboard, respectively. And the J5 block for SCSI LED seems to have too many pins, which leaves some pins for further investigation...

BTW, which pins did you use for the Power switch connection to the case? It should be obvious, but I must be missing something...

I should clean those isa / VLB connectors with a white kind of pencil eraser.. How its now, its really oxidated..

I had the same problem on some cards of mine, but when cleaned they just looked as new again.

The pencil eraser iam using is an white one from hello kitty.

Something like this: but with a different measurement.

The power connector is connected to the power supply. It's an ATX to AT conversion.

The apricot manual appears to be the same one I provided in my vintage-computer.com link.

The more likely reason the TH99 listing for the Apricot board is missing the header is because they simply forgot. I've found more than plenty of mistakes on TH99 over the years.

I did a quick test and the board boots up with BIOS V1.2 R2.4, and the Dallas RTC still has the correct time! I thought I'd need to solder a new RTC, but thankfully, I just noticed it's socketed for easy replacement.

I'll put this aside for a future project when I get all the parts together. Still haven't decided if I'm going SCSI or not, nor decided if I'm going to use all these on-board connectors and save slots for other cards...

Very nice build. I have a few observations/questions.

What's with the external green wires on the CPU card? Was that an expensive post-production "opps", or something you did?

You noted that you have 256 MB installed now, but have you tried 512 MB? Is the 256 MB installed on the motherboard, or CPU card? Have you tried splitting half on the MB and half on the CPU card, all on the MB, and all on the CPU card to see if one configuration allows for faster CMOS memory/cache timings?

What is up with the 8 DIP-28 cache sockets mixed with the 8 DIP-32 cache sockets? There appears to only be a DIP-32 TAG. How does this work? Are there also 5 DIP-20 cache sockets below?

Which cache configuration allows up to 1 MB of L2 cache? Won't 16 DIP-28 cache sockets only accomodate up to 512 KB of cache? I wonder what would be the benefit of running 16 DIP-28 32kx8 cache modules vs. 8 DIP-32 64kx8 modules? Can you mix 8 DIP-32 128kx8 modules with 8 DIP-28 32kx8 modules for a total of 1280 kb of L2 cache? Is there any way to cache all 512 MB of memory? Will the CPU card cache memory on the motherboard, or only memory on the CPU card?

While I have never gotten into EISA, I would certainly jump at the chance to get a dual 486 system running, particularly a dual Cyrix 5x86-133 or X5-160. Even a dual Cyrix MII would be quite the novelty.

The green wires on the CPU card are indeed patchwork from the factory.

I have not tried 512MB of memory because I don't have enough 64MB modules. I have tried running 256MB using four 64MB SIMMs and eight 32MB SIMMs. I didn't notice any problems with either configuration. The BIOS is your typical weird OEM bios (Ambra in my case) so there's really not a lot to play with anyway.

The cache situation is like on your Biostar PCI 486 board. You cannot mix and match the SRAMSs. As this is a Pentium with 64-bit memory, you have twice as many cache sockets. I do not actually know if it can interleave the cache banks, but I suspect not. In that case I will probably upgrade it to 1MB. I need to do further testing first.

1MB can only be attained with eight 128kx8 modules. This board does not support 64kx8 modules as far as I know.

I am not yet sure how much memory can or cannot be cached. I will need to run more tests.

Anonymous Coward wrote:

You cannot mix and match the SIMMs. As this is a Pentium with 64-bit memory, you have twice as many cache sockets.

I assume you meant, "you cannot mix and match the cache DIPs".

I am confused by your second sentence referring to 64-bit memory. If you upgrade to 1 MB L2 cache, you will still be using 8 128kx8 DIP sockets, which is the same as the cache configuration on a 486.

Correct. I goofed up (but I fixed it).

About the 64-bit cache, the issue I was trying to point out was that I don't know for sure if the board interleaves the cache like on a 486 board. Therefore if I just use one bank (8 SRAMs on a Pentium), I could possibly be taking a performance hit. Filling 8 sockets on a Pentium is like filling 4 on a 486.

Aside from the interleaving issue, there could be an issue whereby using a single cache bank may require slower CMOS timings. For example, using eight 64kx8 SRAM modules (512 KB) for the L2 cache vs. four 128kx8 SRAM modules (512 KB) on a 486. The former can handle tighter CMOS L2 timings for FSB's at 40 MHz or higher.

How different is the overall performance from a standard socket 4 build with the more common intel boards?

Intel actually had a Socket4 chipset called the 430LX "Mercury". I believe that was one of the better ones. The SiS Socket4 chipset (501/502/503??) is supposed to offer decent performance as well. So far I can't speak very highly of this OPTi chipset, mainy because of the crumby memory performance. In the PC Magazine review they said this motherboard equipped with a P66 didn't perform much better than their P60 systems...not that there would be much of a difference anyway. From what I gather Pentiums weren't really worth it until pipelined burst cache became available.

If you want to know how different this board performs than an Intel 430FX with async cache, probably quite a bit slower.

Anonymous Coward wrote:

...
For VGA I have settled on #9 Motion FX 771 with 4MB VRAM. This is just about top of the line for VLB. Somehow I only managed to pay a few dollars for this card. This card is somewhat special for a VLB card because of the 220MHz RAMDAC and the VRAM which is mounted on both sides of the PCB. I attempted to run et4000W32P in my system as well, but neither of my cards would power up. This was the same problem I had in my previous OPTi based VLB Pentium system.
...

Can this Tseng issue be related to the motherboard BIOS and/or VGA BIOS?

FYI, I get the complete opposite with the 486 Socket 3 module for this motherboard, i.e. I can get an ET4000W32P working but not an S3 968P - both VLB cards. IIRC, this motherboard requires different BIOS versions for the Pentium and 486 modules.