Uncreative Labs

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

Fortunately I'm not married (engaged 3 times...came to my senses each time).

Not that my current GF really has seen it all... Laughing

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

Ugh. So these IC distributors in China are pretty tricky. They tend to list a lot of chips on their websites that they don't actually have. After I paid them the money a few days later they told me that they didn't have the parts I need. So, I'm back to looking for the 128k x 8 ICs. I think I can find them though. In other news, I did find a place that claims to have the TAG rams I need. They should have shipped today, but I have a feeling when I get them they'll be the wrong part or something. For the money I'm paying they sure as hell had better deliver. They made me buy a lot of 50 even though I only need 3. I doube I can resell the extras. Oh well, at least I have my RTC replacements.

Joined: 19 Apr 2006 Posts: 261 Location: WisConSin

There was a reliable place is CA that got me some god awefull proprietary Hitachi dual port VRAMS for my old futura, they too required I buy at least 50 but then again I only paid $75 with shipping. I got their name dropped when I called through about 5 leads ACME electronics gave me their contact, I can't remember who they were (not a memorable name) But they seemed to have any chip you needed no matter how old, assuming you could pay for them.

I will have to dig and see.

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

Good news. My TAG pieces arrived today....all 50 of them. If anyone else requires this type of TAG piece, please let me know. It looks like if I ever return to the US my 486 will be back in action. I'm still working on the 128kx8 SRAM chips, but I think the guy I bought the TAGs from has them.

*update*
I contacted the seller again, and he does indeed have the 128kx8 SRAMs, though only at 15ns and not 12ns. I think that should be fast enough though. If I need 12ns I'll order it later.
*end update*

Also, yesterday I visited a chip market in Shanghai and I found the RTC that I needed to bring back my previous TMC EISA motherboard. So, now I have two working 486 EISA systems. I guess it's time to start looking for another WIDE SCSI drive.

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

So, I have abandoned my search for the 128kx8 SRAMs. I have actually already found them, and have a decent price on them. However, I found something better. Looking back at previous posts in this thread I found mention of DRAM to SOJ adapters. So, I thought I should look into that possibility again. Sure enough, I found them:

http://www.signalogic.com/index.pl?page=sramadap

This company sells 300mil 128kx8 adapters, so I can have up to 7ns SRAM on my board. I'll probably go with 10ns, or whatever is reasonable since I only have 12ns tags anyway.

Here is my up to date list of things to do:

-Get an additional 128MB of 30pin memory
-Get some 128kx8 cache memories (1024KB)
-Get a new Seagate 36ES2 SCSI drive
-Get Gateway 2000 Anykey programmable keyboard
-Install a CPU fan

*EDIT*

Wow, these 7ns SRAM modules just aren't worth it. It's 40 bucks a pop for minimum order of $100. Does anyone have $4000 to "lend" me? Very Happy

I just went ahead and ordered 25 128kx8 15ns chips instead.

*EDIT AGAIN*

I found another company in Shanghai that claims to have the winbond 12ns chips available. I guess I'll order and see what happens.

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

I have installed the new TAG RAMs into my 486. The performance increase is decent. I went from about 62MIPS to 75MIPs under WinTune 2.0. Most of the increase comes from the cache being operated in write-back mode. Disabling write back decreases performance to around 65MIPS. It's really too bad I can't enable the writeback on the L1 cache. With WB L1 I should get about 85MIPS. My motherboard doesn't support WB L1, but I'm sticking with it because there aren't really any alternatives to a nice EISA board like this. I'm thinking about dropping the bus down to 40MHz and running at 160MHz instead. That should allow me to remove wait states from the main memory. I am curious to see what the numbers will look like.
The systems seems to work pretty well with L2 cache on the fastest settings. Though, the CPU needs a fan because it is getting too hot and overheats sometimes. It is currently cooled by a passive heatsink.
I also need to do something about my AWE32 card, because it keeps losing its eprom information and can cause hardware conflicts when it resets. I'm thinking of installing my AWE64G instead, though I haven't had much luck with it in my 386 so far. It seems Sound Blaster and Adaptec cards don't get along very well.
Finally, the power supply in this unit called it quits. It is a 230W full AT size. Getting a replacement is going to be a hassle. I haven't opened it yet, but I hope it's servicable. My guess is just a bad fuse, but I guess we'll find out soon enough.
Basically I need a few minor tweeks, and a new hard disk and that's about it.

*EDIT*

I was looking for information on the internet today, and I found some interesting stuff on my motherboard. Somebody in the newsgroups claims that it infact does support L1 cache in writeback mode. This is very good, and I intend to test it out tomorrow.

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

So apparently the writeback on my L1 was enabled the whole time. It seems that the writeback cache setting in the BIOS affects both L1 and L2 caches. I was a bit puzzled as to why my 5x86 was only getting 75MIPs at 150MHz. It seemed it should be better than that. I lowered the bus speed down to 40MHz and increased the multiplier to 4x for 160MHz. I was surprised to see that my Wintune score went up to 82.5MIPS?!??! For a difference of only 10MHz the increase in MIPs seems a bit disproportionate. Stranger yet, my memory scores are now at an all time high of 32MB/sec. Removing waitstates from the main memory increased peformance considerably. I was really shocked. I think there isn't much point running your system bus at 50MHz unless you can find some RAM that runs at 45 or 50ns. I've seen the 50ns variety, but it's quite rare. I think I'll leave the system at 160MHz, because it seems to be better in almost every possible way.

More good news is that I was able to get my AWE64 Gold working well in this system. Using the latest version of CTCM seemed to solve all the problems. It didn't work when I tried the same thing in my 386, because the 1542C doesn't seem to like it much. EISA cards tend to be a little less picky about coexisting.

However, I still have a dead power supply. I've been using my baby AT power supply for testing, but it can't be bolted to the case because the screwholes don't align properly.

Joined: 22 Apr 2007 Posts: 264 Location: Ohio/USA

Are 30 pin 16MB SIMMs cheap in China? They cost $40+ here per set on ebay. The only ones I have were found in old 68K Macs I purchased , and they tend to stay in them.

The 486 EISA system I have (DX50, 32MB RAM, all EISA slots) is probably the most stable 486 I own.

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

I actually haven't attempted to look for the 16MB SIMM in China yet, so I am not yet sure of the price. I actually ordered my SIMMs in the USA about two years ago, and at that time they were only $20 for a set of four. If I were a richer man, I would have stocked up. The ones I got were much nicer too. They are 9-chip parity, and use ultra thin surface mount chips.

Joined: 22 Apr 2007 Posts: 264 Location: Ohio/USA

There were documentaries about old obsolete computers being dumped in china and India for parts to be scavenged, was wondering if there was any kind of market for this old stuff there.

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

I am not sure the reason why all the old stuff is being reused. More than likely they are melting it down for materials. Nobody in China would want to use a 486 computer. Hell, even my girlfriend's father who is a farmer and lives in what most westerners would consider to be a shack has a Celeron 800...and he bought that at least 4 years ago. My best guess would be that Chinese retail market is at most 6 to 12 months behind American retail.

Anyway, one thing is certain....the Chinese sellers on eBay seem to make a lot of money selling "collectable" 486 CPUs back to American customers.

Joined: 22 Apr 2007 Posts: 264 Location: Ohio/USA

I was under the impression some of the chips were recycled (not just the CPU but the ones on the motherboards). Could just be gold recovery on the older chips and circuit boards (gold is almost $700 an ounce these days).

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

One of these days I'll have to melt down all of my stuff. I'm probably loaded and I don't even realise it.

Joined: 22 Apr 2007 Posts: 264 Location: Ohio/USA

The very old server CPUs had tons of gold, anything mass produced probably doesn't have that much. But there is more gold per ton of crunched up motherboards then in 1 ton of mined rock, so its worthwhile to process in large scale operation.

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

The EISA 486 will soon be upgraded with the Supermac Spectrum 24 that I recently won on Ebay. It will replace the ELSA Winner 2000 4MB EISA, as that card did not coexist well with my ET4000W32P VLB card....it was causing draw problems in Windows 3.11. I hope that the SuperMac will be a little nicer since it is a true TIGA.

In other news, I have also decided to swap sound cards with my super crappy VLB pentium. I decided AWE64G is too advanced for a 486. I will instead use SB16 with Waveblaster add-on, and AWE32 daughtercard. I will also order a larger wide SCSI harddisk soon, as the 2GB drive is too small and too slow.

The EISA 486 is currently not in working condition, because the full sized AT power supply blew. I am currently in the process of rebuilding it by swapping out the guts from a smaller unit. A different power supply that doesn't properly fit the case is used for testing purposes.