The board has arrived and it turns out that the power is standard AT and the system posted OK.

The VGA DRAM chips are MT4C16257DJ-6 which are listed on eBay UK, but the guy only had one left 🙁

What is the recommended way to connect an IDE cable? All 40 pins are present so all the cables I have as they expect one pin to be missing. I drilled a hole in the connector and that did the trick 😀

For videocard ram (dram type) you should be able to use any chips that are similar from a donor/dead vlb/pci video card . S3/S3 trio/S3DX/Cirrus Logic/Opti/Ati , even if they are from another manufacturer (the ones you have are from Micron) . The only things that are recommended : insert them in to the socket correctly (mind the key) and mach the speed (-6).

For the IDE cable, you need to plug it in so the key tab matches the indent on the silkscreen, if not, there ought to be a indication where pin 1 is (at least that's how it is on my Shuttle board).

red-ray wrote on 2023-03-23, 15:29:

I drilled a hole in the connector and that did the trick 😀

Vynix wrote on 2023-03-23, 21:26:

For the IDE cable, you need to plug it in so the key tab matches the indent on the silkscreen, if not, there ought to be a indication where pin 1 is (at least that's how it is on my Shuttle board).

Thank you, but it would not plug in at all, however I have drilled a hole in the connector and thus far managed to install Windows NT 4.00 SP1 😀

bogdanpaulb wrote on 2023-03-23, 15:51:

For videocard ram (dram type) you should be able to use any chips that are similar from a donor/dead vlb/pci video card . S3/S3 trio/S3DX/Cirrus Logic/Opti/Ati , even if they are from another manufacturer (the ones you have are from Micron) . The only things that are recommended : insert them in to the socket correctly (mind the key) and mach the speed (-6).

Thank you for your post which confirms what I did was sensible. The post was mainly to document the Venturis as I could not find much information.

I feel for a first attempt SIV did OK and 5.70 Beta-01 will likely do rather better. Next I need to install the DE200 I have as this will make things much easier

The vram is FPM and still available on ebay. I used part number without speed.

https://www.ebay.ca/itm/325142871555?epid=126 … ABk9SR9qTqJHiYQ

Cheers,

I've been allays curious if the video dram will work in pairs of 2 FPM and 2 EDO , like the normal ram works mixed in pairs . The specs of the s3 chip states that supports both FPM and EDO.

bogdanpaulb wrote on 2023-03-24, 01:30:

Will video dram will work in pairs of 2 FPM and 2 EDO , like the normal ram works mixed in pairs .

With system memory this depends on the chipset. I had a 440FX system with mixed EDO + FPM, but suspect many chipsets don't allow both at the same time. I don't recall ever seeing a GPU with FPM + EDO at the same time.

I now have 2MB on video ram, I repurposed two chips from another VGA card, and plan to keep an eye out for some cheap (including postage) ones on eBay.

SIV 5.70 Beta-01 now does rather better on my DEC Venturis. The DE200 is now working which makes life much easier as I can just copy files across the network and use the MSVC 6 remote debugger 😀

I seem to have an issue with the CMOS date/time. When I power down the system the time stops incrementing.

Before I powered down the time was correct and the CMOS time was updating. After powering off the system for around 1752 seconds the CMOS time was out by 1752 seconds.

Has anyone seen this happen on other systems and/or know how to fix it please?

My current work around if to automatically do NET TIME /SET /Y \\RED to get the correct time from my main system.

You don't mix EDO or FPM on a video card. This ones on this motherboard is FPM.

Cheers,

red-ray wrote on 2023-03-24, 23:09:

I don't recall ever seeing a GPU with FPM + EDO at the same time.
I now have 2MB on video ram, I repurposed two chips from another VGA card

pentiumspeed wrote on 2023-03-25, 21:52:

You don't mix EDO or FPM on a video card. This ones on this motherboard is FPM.

I didn't, I repurposed 2 x MT4C16257DJ-6 that I had in a S3 Trio64V2/DX 86C775

Thank you for clarifying. Good job, this is correct way to go.

Cheers,

I feel I would like a less slow CPU and am unsure what my options are. At the moment I have as below and expect the board drops the 5.0 volts to 3.0 volts, but the jumpers don't seem to offer 3.0 Volts, then again https://en.wikichip.org/wiki/amd/am486/am486dx2-66nv8t specifies Vcore 3.3 V ± 0.3 V. On the side it says:

J1 = 1-2 : 2x 2-3 : 2.5x Open : 3x
J2 = 1-2 : 3.45 V 2-3 : 3.30 V
J3 = no information - I suspect the J2 settings are actually the J3 settings, but if so what does J2 do?

I suspect a Cyrix 5x86 GP100 will be the most cost effective upgrade as 133 MHz CPUs seem rather pricey, further there are no 4x jumper settings.

What do you guys think please?

J2 should be 2x multiplier for AMD cpu's (it's marked with AMD 2X), because i see that J1 is marked with 'Intel' and unpopulated so if that was the only multiplier jumper, the CPU should be running at 3x33 Mhz and i see in the pic that it's running at 66 Mhz.

bogdanpaulb wrote on 2023-03-26, 18:48:

The CPU should be running at 3x33 Mhz and i see in the pic that it's running at 66 Mhz.

No, an Intel CPU would run at 3x, I currently only have the AMD which should and does run at 2 x 33 = 66 MHz.

As AMD Am486 DX2 CPUs don't support CPUID it's quite tricky to report them as such.

I just found Unknown PGA DX4/2 Interposer which looks identical to the interposer I have. I think it will work with a Cyrix 5x86 GP100, but am wondering "will the BIOS support the Cyrix ?".

Disruptor wrote on 2023-03-31, 20:06:

PCI without slots. Considerable too. […]
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red-ray wrote on 2023-03-31, 19:21:

I guess we can't, I assumed it was ISA and there are no VLB slots on the motherboard. […]
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Disruptor wrote on 2023-03-31, 19:05:

But how can we be sure that it is ISA then? I'm sure it is local bus then.

I guess we can't, I assumed it was ISA and there are no VLB slots on the motherboard.

I just searched the Venturis 486 PC Service Maintenance Manual (EK-A0813-SV. B01) for VLB and it was not found.

The PCI ID is actually reported in the option ROM BIOS !

PCI without slots. Considerable too.

Well, there is no need for it to be VESA-LB if it just is onboard.
As far as I know, local bus devices do not have any special treatment from BIOS.
They may be detected to have double speed at 32 bit transfers compared to 16 bit transfers - if they are not from Cirrus 😉

Try to use CTCM /VID from heise. ctcm 1.7a

This is nothing to do with ISA VGA cards and should be in this thread.

rasz_pl wrote on 2023-03-31, 20:19:

https://theretroweb.com/motherboards/s/dec-ve … 86-433-ver.-1.0 […]
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https://theretroweb.com/motherboards/s/dec-ve … 86-433-ver.-1.0

That board is confusing. SIS ISA/VLB chipset, but
https://vgamuseum.info/index.php/companies/it … th-se-s3-trio32
https://manx-docs.org/collections/mds-199909/ … pc/a0813svb.pdf
VENTURIS 486 Full Profile Models Only)
Device Number (hex) Function
00 CPU bridge
01 ISA bridge
08 Onboard PCI IDE
09 Onboard PCI VGA

there is https://en.wikipedia.org/wiki/CMD640 on board, but where the hell is PCI controller? 😮 so it looks like both CMD640 and 86C732 P are sitting on VLB bus.
red-ray something to keep in mind "CMD640 has data corruption bugs"

It's a 86C764 chip, not a 86C732

Before I got the board I too wondered where the hell is PCI controller? 😮 I feel the manual has errors or the V2 board is different as there are no PCI devices.

I just got an AMD-X5-133ADZ and was concerned when the BIOS reported it as 100 when the system posted, is it common for BIOS of this era to report unexpectedly?
I also tried it @ 160 MHz with the same being reported.

Once Windows was running I was relieved to see the speed was what I expected. How much am I pushing things by running it @ 160 MHz, is there any downsize I should consider?

Careful of this motherboard this contains a CMD possibly 640 which is a issue with IDE reliability.

Cheers,