Re: My DIY ISA Audio Interface

Posted on 2025-04-10, 12:21

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Hi, It's quite interesting and intriguing why your card doesn't work. I have build three of them since I first started the project, and put them in various retro PCs, but the one I use the most has a Pentium MMX CPU running at 233 MHz. I mostly use that for retro-programming and listening to MP3s ( …

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Re: My DIY ISA Audio Interface

Posted on 2025-03-26, 08:29

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

The soldering appears to be of very good quality, thus you're right, it's not from there. But I have noticed that you have JP3 closed. It should be open (i.e.: no jumper set) so that the software could take control of the card. Otherwise, the card would attempt to read the EEPROM, which is empty. …

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Re: My DIY ISA Audio Interface

Posted on 2025-03-25, 10:23

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Hi, I should really turn on the notifications (uh) to catch messages in time. These kinds of issues are a bit hard to debug from a distance. Maybe if you could add a picture of the card? Both solder-side and component-side. It could be anything from a soldering issue (even small solder bridges) to a …

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Re: My DIY ISA Audio Interface

Posted on 2025-02-27, 08:19

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Good morning, I forgot about this thread altogether. With this occasion, I see that I have a few unread private messages -- haha, sorry for the (probably very) long delay for me to reply. I remember I tested generic OPTi 82c924 drivers with Windows 3.11 and they worked. Though, I don't remember …

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

Posted on 2024-09-18, 10:13

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

At a first sight, it looks good. If I were to manually optimize tracks, there could be a few points where the layout could be improved. For instance, I would align vertically the raster of RN1 and RN2. But these are all optical matters, which don't affect the functionality. Just out of curiosity, …

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

Posted on 2024-09-17, 10:06

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Hi PaulV and jyatemu, Indeed, the source of my inspiration for the component layout was that MLI card, as I had it in my spare parts box (I bought it from Micro-Labs directly, one of the last cards that Ted had available). The initial BIOS modifications for the original card were treated in a …

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

Posted on 2024-09-07, 20:33

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Hi, No, the octal bus transceivers (*245) are required, so it’s good to be kept. I had the wrong impression that you used U101 and U102 for video RAM CAS and RAS buffering, but I was wrong. The second time I looked at the schematic, I saw that they are used for the VGA feature connector, something …

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

Posted on 2024-09-05, 20:02

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Well, I tested FantasyLand with the ET4000/W32i card and it doesn't work. Here's a small clip with the display flickering around: https://youtu.be/sgUEaU6eliY I guess there's no need to fire up the Logic Analyzer anymore. A.

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

Posted on 2024-09-05, 06:59

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

I can check that FantasyLand demo on my ET4000/W32i, maybe this evening. Or more certainly during the weekend. However I might not have enough time to connect the logic analyzer to the IRQ9 line to capture the triggering events (if any). I think I should be able to catch IRQ9 events through a small …

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

Posted on 2024-09-04, 12:53

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Yes, I wired the IRQ9 signal in my initial design. But, in MS-DOS, IRQ9 isn't triggered, as far as I tested. I think it was initially intended for vertical retrace purposes. Good point about the ACL. The Windows driver might indeed use it. Well, in this case, please disregard my remark about IRQ9 in …

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

Posted on 2024-09-04, 07:29

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Hi, Nice work on redrawing the schematic diagram. Well done. At a first glance, the diagram looks OK. However, if you're going to use only 4 memory chips, I'd ditch the buffers as they just add complexity to the layout. Also, if you'd like to streamline the design even more, then IRQ9 line can be …

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

Posted on 2023-09-19, 08:57

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

I sent it to you as an attachment to a private message on the forum.

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

Posted on 2023-08-31, 17:59

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Well done, Madao ! Good work figuring out the issue. I really haven't had time for my projects (this VGA card included) in the past couple of years -- usual life business, that is. Back in 2021 or so, I also spotted timing issues on the Hewlett Packard 16500C logic analyzer -- it was a pain to …

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Re: PC Speaker Driver

Posted on 2023-08-07, 10:12

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Ha ha, that was my intention as well. I was once reading about weird hardware cards of the '80s and the '90s and there were all sort of instrumentation adapters and external hardware control. But nothing for the hated PC Speaker. I thought I'd show it some love by designing a card for it. Up until I …

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PC Speaker Driver

Posted on 2023-08-07, 09:33

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Hi, From the category of weird (and possibly useless) hardware , I've designed an ISA card that can control the volume of the PC Speaker through software. I created it in 2021 and wrote the software at the same time, but I didn't have time to assemble the card or test the driver until this summer. I …

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Re: List of open-source PC hardware projects

Posted on 2023-02-16, 10:43

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes, I know. My first SIMMs in 1.6 mm thickness were a very frustrating experience for me as well. And exactly as you say, some of sockets do accept 1.6 mm PCBs but they look a bit stressed. I re-did mine at JLCPCB in 1.2 mm, they work great and are a perfect fit for the SIMM sockets. On the …

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

Posted on 2022-01-24, 13:08

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by ALEKS

in Marvin \ Video

in Marvin \ Video

Hi root42, Unfortunately I had to pause the electronics hobby for some time as I am caught with other responsibilities. I put on hold all my projects (including the new ISA-PCI system backplane that I was working on for my next retrocomputing experiments). I haven't had time to read the forum or …

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Re: HWiNFO for DOS resurrected !

Posted on 2021-11-02, 15:46

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Where is the "computer name" string read from? I have seen that only some mainboards report such a name. Is it an identifier within the BIOS? Or a specific BIOS function that returns this string? Thanks, A.

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Re: HWiNFO for DOS resurrected !

Posted on 2021-10-31, 11:19

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi Martin, Just out of curiosity, I was trying HWiNFO 4.6.4 (I know it's too old, don't ask!) to compare to 6.1.3 on the CX486DLC CPU (well actually I have the TX version but they are basically the same CPU). For the CPU itself HWiNFO 6.1.3 shows the correct and complete name. But for the FPU, …

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

Posted on 2021-10-31, 10:48

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Hi root42, I was busy with other stuff (both daily routine and other microelectronics projects) and haven't had time to check on the VOGONS forum. Yes, I finally reprised working on the ISA video card. The goal is to make it more stable and easier to be replicated by hobbyists. I don't have anything …

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