Re: SNOOP.EXE: (S)VGA adapter info tool and CRT Terminator config utility

Posted on 2023-08-13, 21:59

by

by mkarcher

in Marvin \ Video

in Marvin \ Video

You can easily program the Start Address Low and Start Address High registers in a way you can observe the "Keen issue" on the screen. [...] I don't see a way to find out whether this wrapping occurs or not without asking the user what's visible on the screen. CRT Terminator is able to observe this …

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Re: Ended up with a hord of PCI / ISA cards, some I've never used before

Posted on 2023-08-13, 21:52

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Trident cards DO have primitive 2D accelleration inside them, and scitech display doctor DOES know how to use it. When using SDD, the software univbe handler will thus provide hardware accellerated 2d modes, at higher resolutions. The Trident TVGA series (TVGA8800, TVGA8900, TVGA9000) do not have …

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Re: Ended up with a hord of PCI / ISA cards, some I've never used before

Posted on 2023-08-13, 21:49

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Here comes some "voodoo hype"... The pass-through cable is a standard male-to-male VGA cable, and as I understand it, you can re-use the usual detachable LCD VGA cables as pass-through cables. Wrong. It's male-to-female VGA cable and you can't use standard male-to-male VGA cable as pass-through. So …

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Re: Ended up with a hord of PCI / ISA cards, some I've never used before

Posted on 2023-08-13, 09:29

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So I am quite confident you meant to write AMD 5x86 (internal code name DX5), not AMD 486 DX4. Oops. Yes I meant the AMD 5x86, this one is still working on pure '486 tech', unlike an IBM/Cyrix 5x86c which is beginning to start to behave like a Pentium. Or am I wrong again. No, this time you are …

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Re: Ended up with a hord of PCI / ISA cards, some I've never used before

Posted on 2023-08-13, 07:35

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you can find a decent socket 3 board with PCI slots, and at least a DX4 cpu to feed the Voodoo, you're good to go. An AMD 486 DX4 133 with 16kB L2 write back cache maybe? :P I don't think you suggest running at tripled FSB44 (which board has FSB44?), but at quadrupled FSB33. So I am quite …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2023-08-13, 07:32

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by mkarcher

in Marvin \ Video

in Marvin \ Video

So what happens on real hardware? How long is RDST and/or WRST set? Is it 256 cycles long (256 ACL registers being cleared one by one)? I might be able to write/run a test tool the next days. All terminate in the same location in the code, timed by the rendering clock (the normal SVGA clock crystal …

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Re: SNOOP.EXE: (S)VGA adapter info tool and CRT Terminator config utility

Posted on 2023-08-13, 01:35

by

by mkarcher

in Marvin \ Video

in Marvin \ Video

Looks like indeed the Keen issue is easily reproduced by adjusting the Start Address Low Register (Index 0Dh) and Start Address High Register (Index 0Ch) values, they work differently beyond the 256KB address mark on Tseng and other cards. You can easily program the Start Address Low and Start …

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Re: PSU fuse broken

Posted on 2023-08-13, 01:31

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In my experience, the sequence of events is: One of the primary transistors overheats and fails short. This creates a dead short over the intermediate 300V DC rail when the second primary transistor turns on, so it also overheats and fails short. This creates a permanent short over the 300V DC rail …

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Re: Ended up with a hord of PCI / ISA cards, some I've never used before

Posted on 2023-08-13, 01:22

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The Trident 8900c is the second fastest Trident ISA card ever made, it only has 256k ram but easy to up to 1Mb. The Orchid is a Voodoo 1 and you need the pass-thru cable. The Trident 8900c will only be fast if upgraded to 1MB. At 256KB, it only has 8 bit wide video RAM access, at 512KB, it has 16 …

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Re: Help with some CLK signal quality

Posted on 2023-08-12, 06:59

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Unfortunately where I live it is very, very difficult to access a POST card, even more so one for the old ISA or PCI. I could buy one abroad, but it would take a long time to get to me. I couldn't find in the other thread what troubleshooting steps you already did, and I suppose you are …

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Re: Help with some CLK signal quality

Posted on 2023-08-11, 22:10

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So, there is no apparent problem in the signals?.... I will have to continue investigating why none of the boards work. You should get a POST card, if you don't have any. They are the most easy way to see whether the processor starts to execute BIOS code. For further diagnosis if a processor …

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Re: Pentium 200, non-mmx - low dos benchmarks?

Posted on 2023-08-11, 18:17

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In the process of reading what little Intel documentation still exists for the Advanced/Monaco board, I also discovered that the board was set to feed the CPU 3.6V intseat of 3.3 volts, which would explain why the thing ran so hot that it needed socket 370 heatsink/fan. Hopefully with this I can go …

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Re: Is DOS segment F000:0000h-F000:FFFFh always fully populated by the BIOS?

Posted on 2023-08-11, 17:30

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks all, super helpful. So I suppose there is no programmatic way to detect the size, except to maybe heuristically try to see if a large portion of the address space reads out as 00h or FFh or similar? (like, there is no standardized size field anywhere?) On most BIOSes for 80386 or 80486 …

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Re: SNOOP.EXE: (S)VGA adapter info tool and CRT Terminator config utility

Posted on 2023-08-11, 17:26

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by mkarcher

in Marvin \ Video

in Marvin \ Video

Also I wonder what that Jaton Corp. was.. never heard of them. I've seen the name "Jaton Corp" on a lot of different OEM graphics cards that seem to be based on the chip manufacturers design recommendation. So likely they sold those card imported from Asia for a competitive price in the USA. The …

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Re: EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2023-08-11, 17:22

by

by mkarcher

in Marvin \ Video

in Marvin \ Video

So it keeps setting the terminate bit, read reg 36h, clears the terminate bit and then clears the sync register? So is it expecting something to appear in reg 36h after setting the terminate bit? My copy of a ET4000/W32i datasheet indicates you need to "wait for RDST (ACL Status Register, bit 0) to …

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Re: Help with some CLK signal quality

Posted on 2023-08-11, 17:10

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

With that probe, you are clearly limited by the scope bandwidth only. So my guess of "around 80 MHz bandwidth" wasn't that far off, as the scope is a 100MHz scope. The "1GHz" specification is the digital sampling rate, not the analog bandwidth. You don't necessarily have to repeat the measurement, …

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Re: DIY 10ns/12ns PDIP 28/32 SRAM async caches

Posted on 2023-08-11, 16:56

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Great idea! Thanks for sharing your boards. You might want to add solder pads for a 100n bypass cap close to the chips, especially in the 64k x 16 variant in which you already have a GND and a +5V trace close together near the power pins in the center of the IC. I'm in the process of publishing the …

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Re: Soyo SY-4SAW Motherboard with corrupted BIOS - Need help

Posted on 2023-08-11, 16:49

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by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Nonetheless, I'm still surprised, that I sometimes got a picture with EDO modules installed, even if it was only the AWARD Bootblock BIOS v1.0 screen. Going into the boot block screen is a known and common failure mode for Sis 496/7 based mainboards if you install EDO RAM and you don't have the …

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Re: Soyo SY-4SAW Motherboard with corrupted BIOS - Need help

Posted on 2023-08-11, 05:54

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There was never a problem with this motherboard to begin with. It's all user error. It turns out, this board really doesn't like double-sided SIMM modules. Once I swapped it against a single-sided module, the issue immediately vanished, and the board posts normally. There likely is an issue if the …

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Re: Help with some CLK signal quality

Posted on 2023-08-11, 05:48

by

by mkarcher

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

All the clock signals you show don't show any obvious problems with the clock signals. The ringing you see on the 8MHz clock can be caused by your measuring method: To make sure you get the edge displayed right, the standard alligator clip ground setup is insufficient. A short wire front the end of …

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