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Post by GiGaBiTe on Aug 30, 2010 5:52:32 GMT -5
VLB was nothing more than pins mapped directly from the 486s address and data bus, with a few extra pins for timing and control logic. Since the 486 was based on the 386, they share a number of similarities and it should be possible to make a VLB slot work with a 386.
The only limitation is that you'd have to use a 386DX (32 bit address and data buses), because a 386SX only has a 16 bit data and 24 bit address bus, and VLB is a 32 bit slot.
The issue I see with doing something like that board is that it would be VERY slow. A 40 MHz 386DX can barely keep ground with a 25 MHz 486SX, and driving a VLB card would put a hefty load on the bus, which is probably why they only put one slot on it.
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Post by Tom Maneiro on Aug 30, 2010 11:25:52 GMT -5
Nice motherboard. Fortunately for us, VLB was a short-lived messy experiment I didn't know that VLB was so old (or that some motherboard builded bothered to mess with VLB on a 386, given the problems and oddities). Looks more like a proof-of-concept than anything useful.
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Post by GiGaBiTe on Aug 30, 2010 16:08:58 GMT -5
Just like when any new technology comes around, the older generation still stays around for quite awhile (take the Core 2 and the i3/i5/i7.) And sometimes technology used on newer stuff is back ported to the older generation (like Core 2 motherboards came standard with DDR2, and some of the newer boards added DDR3 support.)
It was probably the same for VESA, 486s were very expensive when they came out and someone thought to take the VESA slot and use it on a 386 for cost effective reasons.
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Post by Tom Maneiro on Aug 30, 2010 16:19:54 GMT -5
Is there any PCI-based 386 system out there? I'm curious... if any of these do exist, it could be some highly-specialized embedded stuff... Late 486 boards came with PCI slots (i had one of these, a PCCRAP M9-something - PCI, ISA... and VLB, all in the same board!), and there were very few Pentium boards with VLB (like this Socket4 thingy - this one has NO PCI, though...). Those suckers that spent good money on "high-end" VGA and SCSI VLB cards surely were pissed when PCI was introduced, so makers of motherboards obviously pushed VLB for a bit more, until it vanished completely...
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Post by GiGaBiTe on Aug 30, 2010 18:16:09 GMT -5
Anything is possible, but the 386 was so old and slow by the time PCI came around that it was uneconomical to even attempt to make the two work together. You may have been able to drive at least one PCI slot on a 386, seeing as someone made a VLB slot work with a 386 (they have the same throughput at 33 MHz theoretically.)
Even if someone attempted to try it, you'd have to design a new bridge chip to work between the two and devise some clock divider to keep the PCI slots at 33 MHz. PCI cards are usually very unforgiving of overclocking the bus and would frequently fry or just not work.
People who spent good money on VLB cards probably spent more good money on that Pentium VLB board. I don't even want to think about the nightmare of interfacing something based on the 486 onto a pentium design.
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Post by theelf on Sept 8, 2010 14:55:27 GMT -5
;DHI!!!!! wooowww today i win a bid for a 386DX-40 with VLB!!!! cgi.ebay.es/ws/eBayISAPI.dll?ViewItem&item=290469534714&ssPageName=STRK:MEWNX:ITNow i need to buy a VLB video card, here in spain is impossible, but sure in ebay USA i can buy one! i like to buy a ATI Mach32 VLB, hope i can find one..!! mm... a 386DX-40, 32mb ram, Ati mach32 VLB.... I CAN´T WAIT THE MOTHERBOARD TO COME!!!! First thing i made when i have in my hands... is make Doom Benchmarks... ;D !!! A question, someone knows if a 387 FPU speed up Doom? i think doom engine not use FPU at all, but maybe i wrong! or exist some unofficial build with FPU support..? thanxs
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Post by nextvolume on Sept 8, 2010 16:38:48 GMT -5
I have a 386 motherboard as well. LinkPhotos (old: late 2008)Until some days ago it seemed that it didn't work anymore, but oddly for its sake I tried to power it on some days ago and it's still working. I do not have any PS/2 or AT keyboards laying around at the moment, though (but they're easy to find at the flea market). I saw a VLB card at the local flea market. Check flea markets often, you aren't going to get what you want when you want it, but you will probably get it someday and you will get it very cheap for much less than what you will be asked on the internet. I check my local one at least once a month. I ran Linux on the machine when I still used it to some degree. It was my custom uClibc based distribution with a 2.4 kernel, running in 4 megabytes of RAM. While that might sound very strange, it is actually simple to do something like that. For people who can do it and have the tools (I don't have all the tools yet), one could try desoldering the big AT keyboard socket and replacing it with a PS/2 socket. In this way no adapter will be needed. It should work, but it's something I have only thought about and never done currently. - nextvolume
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Post by GiGaBiTe on Sept 8, 2010 18:45:16 GMT -5
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Post by Tom Maneiro on Sept 8, 2010 22:16:48 GMT -5
Damn, back in my university, we had one or two VLB framebuggers laying around As for the 387, why not just overclock the bastard instead of looking for a (possibly) non-existing part? Mine does fine at non-stock 40MHz ...although AIDA insists that it's actually a 287... but whatever. As for DooM, it could be placebo, but the speed gain is almost unnoticeable. Where i did noticed some improvement was on NO$GMB - with the 387, sound emulation is a bit faster.
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Post by GiGaBiTe on Sept 9, 2010 1:29:04 GMT -5
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Post by theelf on Sept 9, 2010 7:13:55 GMT -5
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Post by GiGaBiTe on Sept 9, 2010 15:36:26 GMT -5
I'm pretty sure the Cyrix 387 was one of the fastest FPUs available, and it's cheaper than the IIT. I say grab the Cyrix one.
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Post by Tom Maneiro on Sept 9, 2010 19:02:00 GMT -5
But but but that's a DX I only have the lameloid SX... and i suppose that 40MHz 387SX's only exist in my dreams... EDIT: OK, it seems that the 387SX-40 is not too unreal: www.cpupages.com/store/index.php?id_item=1239But still, most 'SX boxes came with PLCC FPU sockets, not PGA...
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Post by GiGaBiTe on Sept 10, 2010 3:40:36 GMT -5
I would say desolder the 386SX on your motherboard and solder on a 386DX, but it would be missing 16 data lines and 8 address lines, wouldn't work too well
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electronixguy
Moldy Popcorn
Microsoft? Is that some kind of toilet paper??
Posts: 36
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Post by electronixguy on Sept 17, 2010 16:57:38 GMT -5
It's been a while since I've been around here, things haven't changed too much though Finally got my hands on an old 386! Ambra 386sx-25 2MB RAM onboard, 8MB installed with 2 4MB SIMMS Put a WD Caviar 2200 in it Dos 6.22 + Win 3.1 5.25 floppy was utterly shot, replaced with Asus CD-RW as IDE slave. @tom: what was the name of that DOS-based CD burning app you tried before? Think I'm going to get my hands on an ISA ethernet board & put this relic online with Arachne or Lynx for DOS... There's my little update for anyone who remembers/cares Cheers
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