Uncreative Labs

Guest

Gateway 2000 desktop cases with an AT PSU are worth something?

Or is it specifically the 286 true at gateway case that is worth money?

Mind providing a linky to the case you lost on?

I may have an AT gateway 2000 case that originally fit a 486 system.

Cheers

Guest

Oh and if I were you I would just run the plain AMD 5x86 at 5v, don't mess with the Evergreen as long as you have a heatsync and fan it will run and at 5v you can get it up to 150 or 160mhz

NORMAL 5x86 chips are built like an army tank and as long as they don't melt down they always seem to keep chugging

Good Luck

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I think just the full sized Gateway 2000 AT cases are worth something. The Baby ATs don't seem to go for much. Here's the link to the auction if you want to see it:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=51110&item=5152852225&rd=1&ssPageName=WDVW

Anyway, I would highly advise against not running your 5x86s at 5v. AMD says that the AMD 5x86 is 5V I/O tolerant. However, all 3.3V chips are designed in this way. The 5x86 is not 5V core tolerant. There are several cases in which people have ran their 5x86s without a regulator, however it will significantly reduce the life of the chip if it doesn't destroy it almost immediately.

Guest

"There are several cases in which people have ran their 5x86s without a regulator, however it will significantly reduce the life of the chip if it doesn't destroy it almost immediately."

Hmm, one of mine has been running 5v for over 5yrs now. I guess it depends on which model of the chip your talking about, I bought it for a whopping $9 back then so I figure what the heck?

And I see why that "case" sold for $$
the software! I doubt it had anything to do with the case Smile

Good Luck

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I guess it could be the software. However, I think that's just plain silly. I don't see anything in there of much interesting. Anyway, I'm really pissed off because I really want one of those cases, and they don't appear on eBay very often. Maybe once or twice every four months or so.

Anyway, at least I located a replacement regulator. Yet another part I had to order from Germany. This time it had better work, or I'm going to get really pissed off. The 5x86 should be pin compatible with a 486DX!!!! I shouldn't be having these problems.

Posted: Tue Jan 18, 2005 4:27 am

The 5x86 was a strange duck in terms of compatbility, especially on newer (but not new enough) motherboards. Usually if your board had full jumpers for everything up to but not including the 5x86 you were screwed in getting the 5x86 working right, (usually because the board would automatically enable write-through without proper cache) yet if your motherboard had no jumpers it would work OK and the same if it was designed for the chip natively.

Now I might have a Gateway case that is as you describe but I have to look at it closely, I have about 10 different gateway barebones AT desktop cases of misc sorts. I might have a full but I have too dig it out of my pile of 50 junked PCs; which is no small task. Especially since the one I am looking for, I am quite certain, is at the very bottom Sad

Good Luck

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Hmmm. Well don't dig too hard unless it's in good cosmetic condition. I have spent quite a lot of money on this 486 system of mine and presentation is important to me. Cool

I think it was possible to run the 5x86 in DX/4 only motherboards by purchasing an extra PGA socket to put between the ZIF and the CPU and hardwiring your cache and multiplier settings in.

Posted: Tue Jan 18, 2005 6:59 pm

"I think it was possible to run the 5x86 in DX/4 only motherboards by purchasing an extra PGA socket to put between the ZIF and the CPU and hardwiring your cache and multiplier settings in."

Nope, its IDENTICAL to a 486DX except with extra features (which luckily your motherboard can ignore if its old and run fine), the multiplier is set by wire wrapping a pin to the case on old motherboards. (or it runs 3x by default)
On motherboards that jumpered the multiplier the multiplier was set the same way, it connected a pin to ground.

You do need a socket 2/3 motherboard though! Socket 1 can be problematic for other reasons (cough... no amd DX support).

Now your thinking of the Cyrix 5x86 which is a true 5x86, the amd is really just a 486DX5 as they called it in the day with no real landbreaking architectural changes, hence it should be compatible most of the time, though its new features are not enabled.

The cache settings are controlled by the motherboard bios or jumpers, if its OLD it will not recognize the additional cache mode and work OK if its newer but not new enough you end up with the board trying to enable a caching method that may not be compatible with your cache. (and usually there was no jumper/bios setting to help) And usually you couldn't boot or got random freezes if this was the case.

Good Luck

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I am pretty familiar with both the Cyrix and AMD 5x86 chips. I am quite certain that the internal cache of the AMD processor can be forced into write through mode by wiring pin B13 to ground. In this configuration the chip should be able to run properly in a standard 168pin socket (with the use of a regulator of course). I've heard of many people running am5x86s in this way.

What extra features does the am5x86 support? The only changes I am aware of are as follows:

-3.45V core voltage
-16kb of internal writeback cache (which will also operate in write through mode)
-.35 micron fabrication process
-enhanced power management
-internal 3X and 4X multiplier support

I know that with the intelDX/4 there were problems with old motherboards recognising the entire 16kb L1 cache, but I was pretty sure that this did not affect the am5x86 cpus.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Well. I am still working on this problem, and I am thinking that maybe I have finally found a solution. My second 486 voltage regulator adapter came in the other day. I'm not sure if it works yet, because packed away my CPUs and I didn't have time to do any testing. The only thing that I found disappointing about this unit is that it is lacking a jumper for writeback/writethrough cache. Thankfully the AMD 5x86 is set to WT by default. If I want to try running writeback, I suppose I could try wiring up my own interposer. Infact, I think I already have one that's pre-wired. Just incase this adapter didn't work, I took some precautions by ordering three more of them. That brings me to a total of five interposers and one 5x86 overdrive. I'm sure glad it's still not 1995 or I'd be broke.

I also got a chance to look at my Hercules Dynamite Power manual the other day and it seems to support only output modes through it's VGA feature connector. This means that I must find a way to put the connector on the Winner 2000 into input mode. I am not sure how to do this yet, because documentation for this card is not currently available.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I was looking on German Ebay and I have found what I think is an acceptable replacement EISA motherboard. I was really hoping to find a TMC so that I could have sixteen 30-pin memory slots, but I suppose that 128MB of memory is enough for now. Anyway, it's an Asus 486TA board with SiS chipset, AMI-BIOS, two VLB sockets and eight 30-pin SIMM slots. It also works properly with a POD83, so hopefully that means I can use other writeback cache chips such as the Cyrix and AMD 5x86. I'm getting a bit tired of playing around with this TMC board of mine. The jumpers on it are really goofy, and I because the documentation on TH99 is not 100% correct, I can't figure out how to properly set the divider on the ISA bus. Many 486 board allow you to do it in the BIOS, but my TMC does not. Hopefully the BIOS on this Asus board is a little more impressive.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Well the board on German Ebay seems to be costing too much. Currently it would cost me at least $50US to purchase the board and pay for shipping. Thankfully, I have found another board on Canadian Ebay. While it's made by a smaller company I think it could be a better board. The board is made by NICE/MCCI/Lion Computers Inc. It is a late model EISA board with an AMI BIOS, SiS chipset and sockets for up to 1MB of level 2 cache. The board also has sixteen 30-pin SIMM sockets for up to 256mb of main memory, and features one VLB slot. This board is very similar to the one manufactured by Tyan computers. It is also made in the USA, so hopefully the quality should be a little better than the crap from out east. Unfortunately, I have read that there are some hardware incompatibilities with this board regarding certain video adapters and the VL bus. These were corrected in the 1st revision, however I suspect that the board I am looking at is an older model. Supposedly this board also supports writeback-cache, but I doubt it works properly. I will test it none the less. Hopefully I can get this board going with one of my many VRMs.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I have finally had some luck getting my 5x86 going at 150MHz using one of my VRMs. I think when I get my new motherboard I should be able to squeeze some more power out of it though, since there are more settings to play with and I think the L1 writeback cache will work with an SiS chipset. The board was made around 1994 or so. I think that the L2 cache is also writeback. Does anybody know where I can get some 128KB (1024kb) density cache chips? I need either 12ns or 15ns.

While I was doing some testing I noticed how much faster the 5x86 operates at 100MHz than a DX/4 overdrive chip. I'm thinking at least a 50% improvement. Running GTA at 640x480 produced some pretty good results at both 100 and 150MHz. I think I might be hitting the peak bandwidth of the display adapter. I'm getting between 15-20FPS. When I get the new board I am going to try to run with 0WS on the VL-bus. I'd also like to get the ISA version my ET4000W32P card for comparison.

I think that this NICE motherboard is going to be really NICE. I saw some benchmarks at 50MHz on the newsgroups and it consistantly produced the best results in memory and disk bandwidth. The auction for this board ends tonight, so wish me luck.

Posted: Mon Feb 14, 2005 5:21 pm

If your still using the ISA card, I noticed that most ISA vid cards (especially ones that come in both VL and ISA varieties) can be overclocked easily by changing the bus divisor, get it up around 12mhz or 16mhz and it will fly!

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Yeah, that's a pretty good idea but it doesn't work very well if you're not running your disk controller on a local bus. Overclocking ISA and EISA disk controllers always always always causes data corruption. I'm having this problem right now because my piece of crap TMC motherboard doesn't seem to allow me to adjust my ISA dividers, and my EISA controller is particularly sensitive because it's SCSI.

Hopefully this will not be an issue when my NICE EISA board arrives. At least it sure as hell had better not be for $35!!!! But, I had no choice. I seriously doubt we'll be seeing anymore decent EISA boards on ebay for quite a while. Good thing the auction ended at 3:00AM. I could have ended up paying a lot more during ebay prime time.