Search results for AMD \ VOGONS

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-13, 19:01

I have several Cyrix 5x86 chips, none of which have the 4x multiplier 2x Cyrix 5x86-120 1x Cyrix 5x86-100 2x IBM 5x86-100HF in a Gainberry upgrade marked as 120 Mhz I wish there was an easy way to short, or add some diode or resistor to force these into 4x mode. Maybe there is. Does anyone have a …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-13, 19:56

by udam_u

in Marvin \ General Old Hardware

The 5x86-100 I have runs fine at 120 Mhz, so I am thinking the 120 Mhz would run fine at 133 Mhz? My Cx100MHz used to run at 150MHz after I had applied 5V. (: Here you are link: http://www.vogons.org/viewtopic.php?t=27012&postdays=0&postorder=asc&start=20 If I were You I would try overclock your …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-14, 03:41

by feipoa

in Marvin \ General Old Hardware

How would you overclock a Cyrix 5x86-120 to 133 Mhz that has a 3x multiplier? I can see using 50 Mhz FSB and a Host-PCI clock division of 2:3 for 150 Mhz. But I doubt the Cyrix 5x86-120 would be stable in Windows with 30 Mhz of extra boost. I will try it on my Biostar MB-8433UUD v3.0 and M919 v3.4 …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-14, 04:39

by feipoa

in Marvin \ General Old Hardware

udam_u, could you also post what other BIOS settings were required for operation at a 50 Mhz FSB on your Cyrix 5x86-150? I didn't see it in the other post. I briefly attempted this at 5V and 50 Mhz FSB but didn't get past memory check on my M919 w/128MB EDO RAM. It went to about 109,000 KB and froze …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-14, 09:19

by udam_u

in Marvin \ General Old Hardware

@feipoa How would you overclock a Cyrix 5x86-120 to 133 Mhz that has a 3x multiplier? I can see using 50 Mhz FSB and a Host-PCI clock division of 2:3 for 150 Mhz. Hi, there is very simple way. You have to discover hidden 66MHz fsb setting and set multiplier to 2x. Rg100 found Biostar hidden settings …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-14, 09:31

by retro games 100

in Marvin \ General Old Hardware

I think that UMC PCI 486 mobos have things in common, and these are their ability to use EDO RAM, and to unofficially allow 60 and 66 MHz bus speed. The M919 is no exception. Here are the highest bus speed jumper settings: Key oo = open jumper -- = closed jumper 60 MHz oo -- oo 66 MHz -- oo --

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-14, 10:25

by Tetrium

in Marvin \ General Old Hardware

I'm not sure what 486 chipsets support EDO ram. I know some of the newer UMC ones support EDO, and perhaps some revisions of the SiS one too. Btw, good posts udam_u and RG100 😉 The only thing I could possibly add is to check if your cache modules are at least 15ns before attempting 66Mhz FSB.

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-14, 14:46

by feipoa

in Marvin \ General Old Hardware

Thanks for the tip. I'll test the 66 Mhz, 2x, 1:1/2 trick out on my MB-8433UUD and M919 using some less-rare cpu first. L2 is all 15 ns. From what I remember reading some time ago, if the UM8881F chipset has an E, as shown below in the given location of -EYT, then it supports EDO RAM. UM8881F 9633- …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-18, 16:39

by retro games 100

in Marvin \ General Old Hardware

From what I remember reading some time ago, if the UM8881F chipset has an E, as shown below in the given location of -EYT, then it supports EDO RAM. UM8881F 9633-EYT R62706 Thanks for the info. Do you know if there are any UMC 486 VLB mobos that support EDO, or was this feature limited to the UMC …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-18, 20:22

by feipoa

in Marvin \ General Old Hardware

PC Chips M919 has a single VLB slot, 3 PCI slots, and supports EDO. v3.4 has a fairly recent BIOS -- May or June 1996. I use this MB on my testbed.

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-18, 20:39

by retro games 100

in Marvin \ General Old Hardware

PC Chips M919 has a single VLB slot, 3 PCI slots, and supports EDO. v3.4 has a fairly recent BIOS -- May or June 1996. I use this MB on my testbed. Sorry, I should have been more specific in my enquiry. When I asked about EDO RAM being supported on a UMC 486 mobo that has VLB slot(s), I really …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-18, 22:33

by Tetrium

in Marvin \ General Old Hardware

PC Chips M919 has a single VLB slot, 3 PCI slots, and supports EDO. v3.4 has a fairly recent BIOS -- May or June 1996. I use this MB on my testbed. Sorry, I should have been more specific in my enquiry. When I asked about EDO RAM being supported on a UMC 486 mobo that has VLB slot(s), I really …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-18, 23:49

by feipoa

in Marvin \ General Old Hardware

I am generally inclined to agree with Tetrium. I have had a 486 motherboard with 3 VLB slots (no PCI), 4 72-pin SIMM slots, and a working PS/2 mouse port. It was the only PS/2 mouse capable non-PCI 486 motherboard I had ever seen. I'm sorry now that I let it go. I did not try EDO RAM in it, nor did …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-19, 03:38

by Tetrium

in Marvin \ General Old Hardware

When VLB was brand new, it was basically VLB or only ISA, and since manufacturers wanted to sell as many boards as possible, they perhaps just put 3 VLB slots to make it sound better? My guess for wanting a VLB-only board is to avoid having the VLB slots bridged together with the PCI slots?

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-19, 19:12

by swaaye

in Marvin \ General Old Hardware

Good luck determining which are bridged and if they are even better as a result. I'm not sure that there are quality VLB and PCI 486 chipsets. Even the Intel PCI chipsets suck. Perhaps even more important is board quality though. Not sure if there are exceptional boards either. :D I have a feeling …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-20, 01:34

by udam_u

in Marvin \ General Old Hardware

Good luck determining which are bridged and if they are even better as a result. I'm not sure that there are quality VLB and PCI 486 chipsets. Even the Intel PCI chipsets suck. Why do you think that all 486 PCI implementation suck?

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-20, 03:22

by swaaye

in Marvin \ General Old Hardware

Because I haven't heard of or used a good one. They tend to have horrible busmaster DMA performance (as in high CPU utilization and low bandwidth) and funky IRQ issues. Part of it is simply due to them being early PCI designs and because the boards are often low quality. Their age also means that …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-20, 04:48

by Antinomy

in Marvin \ General Old Hardware

swaaye, nice info! But why don't I see UMC? 😉

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-20, 12:46

by retro games 100

in Marvin \ General Old Hardware

I want to test a good 486 VLB only mobo, to see if it's any faster than a 486 mobo that uses PCI. I understand from reading old posts on Vogons that a good VLB board is better than most (if not all) PCI boards, in terms of video performance. I am beginning to doubt this notion, having seen my PCI …

Re: UMC chipset PCI 486 mobo. AMD P90 CPU options?

Posted on 2011-03-20, 18:48

by swaaye

in Marvin \ General Old Hardware

Well VLB is literally a bus that comes right off of the 486 CPU so it is likely to be best. Especially when PCI on 486s doesn't have good busmaster support which is a PCI highlight over VLB. And this is mainly because PCI is most often connected to VLB. However there's no doubt that there are better …

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