Re: TSENG 4000 VLB - dim picture output

Posted on 2021-04-06, 12:32

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Most probably it is the RAMDAC VREF voltage. Check the datasheet of the RAMDAC (yours appears to be a Winbond part) and see what voltage it expects on the VREF pin. Then check with a multimeter if the required voltage is present at the output of the resistor divider next to the RAMDAC. Normally that …

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Re: HWiNFO for DOS resurrected !

Posted on 2021-04-05, 18:37

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi Martin, There is an issue with the keyboard controller detection on my system. Please see the picture below. My keyboard controller is VIA VT82C42. I know it cannot be detected by its name but at lease you can specify the keyboard controller version as reported by issuing command 0xA1 to port …

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-30, 07:30

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

I have seen the memory range array in the ASM code as a string of DBs. Maybe the ROM BIOS image was made for ET4000AX as well? That one can handle 256K. Then again, at page 186 of the datasheet, the hardware memory addressing lines are described. And the minimum is 512K. I think the BIOS might be …

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-29, 12:26

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

That was a great read! And good thing you are now detecting the RAM correctly. Thank you for the analysis. Indeed 256K is not supported by the W32i variation. I did a quick search on the Internet and found out the following source code that targets the ET4000/W32i amongst other stuff. Maybe it is of …

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-28, 16:22

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Regarding the RAM, it's not really weird. The ET4000/W32i can access: * maximum 4 Mb of RAM in linear mode * maximum 2 Mb of RAM in interleaved mode (that is still physically 4 Mb of RAM but only the addressing mode differs in a way that the CAS pre-charge time of one bank is happening at the same …

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-28, 15:24

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Thank you, Pierre32 ! superfury I will try to make a videoclip with the Tseng tests. Especially that yesterday I just scored locally a very little used AOC 17" CRT monitor for $ 5. My trusty EIZO just started developping a redish tint a couple of minutes after power on -- I will try to fix it when I …

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-27, 16:32

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

I ran it again and this time it displays the following hex numbers: 88 88 80 80 80 My system is made of hardware entirely designed by me: - ISA System Backplane - ISA 80386DX Singleboard Microcomputer - ISA ET4000/W32i Video Card - ISA I/O Interface - ISA Audio Interface - 32 Mb SIMM Modules When I …

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-27, 07:21

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

I ran the new program but this time, immediately upon execution, the screen goes blank and then it deactivates (!?) the video card completely. Also killing the output signals. The CRT monitor shuts down (as in no signal received). Only a hard reset can get the video card reinitialized.

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-26, 17:24

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

I ran the updated version and it displays these numbers: 88888088 Hope this helps!

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-26, 15:02

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

I have ran the .COM program but it either does nothing or it does what it was intended to but in a very quick fashion. The screen goes black for an instant then quickly reverts back to the standard command line. You can add a BIOS read key routine or something after printing the numbers so that I …

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-26, 13:09

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Thank you for the kind words. I think this is the best I can get out of the ISA bus in terms of video cards. I used the fastest memories that I could find available (and because of this I had some timing issues in the early design stages) but the real bottleneck is the bus itself. My ambition was to …

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Re: EXCELGRAPH - ISA Video Display Controller

Posted on 2021-03-25, 20:24

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Unfortunately I don't know of any consacrated way of testing the ET4000/W32i controller. I have empirically tested the graphics card using software that I know the behavior of. I have encountered some issues but they were all hardware related and I fixed them during the development of the schematic …

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EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)

Posted on 2021-03-25, 12:00

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Hi, Last year I worked on one of my x86-related microelectronics projects: an ISA video card. It is based on the Tseng Labs ET4000/W32i video display controller chip. It is equipped with 4 Mb of DRAM connected in interleave mode which gives me 2 Mb of usable video RAM with almost 64-bit memory …

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Re: The comprehensive list of all modern reproductions of vintage sound cards

Posted on 2021-03-16, 18:25

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

LightStruk already added it to the first page of the thread. But here is a direct link. Cheers,

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Re: The comprehensive list of all modern reproductions of vintage sound cards

Posted on 2021-03-16, 14:16

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Thanks for adding my card. While it's true that I programmed the entire driver, I also used some portions of code (especially the SBPRO and MPU interfaces) from Jan Knipperts. Without those parts the driver wouldn't be what it is. Cheers, A.

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Re: List of open-source PC hardware projects

Posted on 2021-03-16, 10:54

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for the broken links hint. I corrected them already. Regarding why the floppy disk drive controller does not work whith my test system with a P233MMX CPU, I don't know the root cause, yet. Debugging this kind of issues is very time consuming. I do have access to the test equippment required …

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Re: List of open-source PC hardware projects

Posted on 2021-03-16, 07:28

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I wasn't aware that my projects present such interest. I updated the web pages and included the Gerber files for the designs that I tested and deemed as working. PS: You might want to modify the links as I moved some pages. Also I think the audio interface card is missing from the list above. Thanks …

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Re: My DIY ISA Audio Interface

Posted on 2020-10-02, 19:34

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

I used NJM2100 for the YAC-512 converter, between the AOUT and SWIN pins. Indeed I might just reconsider using a better quality OPAMP in this position. SE5534 are individual output amplifiers directly connecting the CODEC left and right outputs to the line out connector. I just had them in my drawer …

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Re: 4Mx9 70ns 30-pin SIMM

Posted on 2020-10-02, 18:52

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thank you! I never thought about designing a 16 Mb module. It shouldn't be that hard. But it will be of a different size. A little bit taller. Although I know there are some 16Mx4 IC of reasonable size. With a 2 IC per PCB, they would look very compact. However I don't have any piece of hardware …

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Re: My DIY ISA Audio Interface

Posted on 2020-10-02, 18:32

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Thank you! I really enjoy designing hardware and PCBs layouts. Especially when I am designing the hardware that I wanted and never had any chance to have back in the '90s.

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