Re: My DIY ISA Audio Interface

Posted on 2020-10-02, 18:23

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Thanks Tiido! I will take a look at NJM4580. By the way, I am using a NJM2100 but only for the FM DAC. It was readily available on Mouser and cheap enough. The SE5534A is quasi-unobtainable (but I had 4 NOS in my parts box, so I used them) but easily replaceable with NE5534A -- which is cheap. And …

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Re: My DIY ISA Audio Interface

Posted on 2020-10-02, 14:45

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by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Only two tantalum capacitors are in the signal path. It's true that they could produce overtones or sound harsh, but during my tests I haven't heard anything bad. But I agree those two 10 uF parts could be replaced with bipolar Nichicon ES series parts. All the rest of the tantalums are exclusively …

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My DIY ISA Audio Interface

Posted on 2020-10-02, 10:41

by

by ALEKS

in Marvin \ Sound

in Marvin \ Sound

Hi, I wanted to share with you something that I was working on for a while. It's an ISA sound card that I designed for my own DIY computer. The PCB is on 4 layers, top and bottom being signal layers and inner layers being supply rails. I used individual analog and digital ground and power planes. …

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4Mx9 70ns 30-pin SIMM

Posted on 2020-09-29, 15:45

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, Lately I built some SIMM memories for personal use. I am using them with 80386 machines. I know there are other newly made SIMMs. But I would just like to also share my project with you. Unfortunately I wasn't paying attention that SIMM sockets expect 1.2 mm PCB thickness. Mine are 1.6 mm and …

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Re: HWiNFO for DOS resurrected !

Posted on 2020-08-20, 08:31

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for the fix. It works correctly now! hwinfo-detection.jpg One more thing though. Not that it matters most, but launching the program by using a relative path to the .EXE file, from the current directory, still throws a < Cannot open "HWiNFO.DAT" ! > fatal error. In other words, HWiNFO resides …

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Re: HWiNFO for DOS resurrected !

Posted on 2020-08-20, 07:49

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have made a .ZIP file with the ROM images extracted with your utility.

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Re: HWiNFO for DOS resurrected !

Posted on 2020-08-20, 07:21

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I tried with older versions (V.5 and V.4.6.4) and both report no ROM extensions on this particular machine. Maybe there is something wrong with the PC that I am using, that confuses HWiNFO's detection mechanisms. Is there anything I can do (generate a report, or send you some information from BIOS …

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Re: HWiNFO for DOS resurrected !

Posted on 2020-08-20, 06:20

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for the updates on the release notes. Now coming back to the BIOS extensions, in my case, HWiNFO lists none, as pictured. hwinfo-no-extensions.jpg In this particular case, the ROM is placed at D000-D1FF (but can vary by DIP switches if there are other cards installed). As a side note, these …

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Re: HWiNFO for DOS resurrected !

Posted on 2020-08-19, 17:20

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for the new version. I checked it right away. Can you put some quick release notes on the first page, as you did with the other versions (I think I said it before, I really miss the "hwinfo.his" and "hwinfo.lst" files)? Apparently it still won't detect my I/O Interface. Cheers, A.

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Re: HWiNFO for DOS resurrected !

Posted on 2020-08-09, 07:26

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There is another bug that manifests if, for instance, I launch HWiNFO without being in its directory but by using a command of this type: hwinfo\hwinfo.exe (".exe" part is optional in MS-DOS as the OS will search for ".bat", ".com", ".exe" files of that name anyway) It will quickly throw up an error …

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Re: Changing VGA ROM Fonts

Posted on 2020-07-17, 12:57

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Hi VileR , Yes, in the end I hand-crafted all the fonts in the ROM. I did 8 x 8, 8 x 14, 9 x 14, 8 x 16, and 9 x 16 (exactly the ones in the updated pictures on my site). Then I embedded all in the modified ROM image. Thanks again for Fontraption! Looking forward for the fixed (and updated) version. …

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Re: Changing VGA ROM Fonts

Posted on 2020-07-17, 10:22

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Thanks! The enclosure is on my TODO list. Also I want to source an electromagnetic ballast instead of the pure resistive one (made of light bulbs). I took the pictures remotely (with timer) with the camera on a small tripod. Needless to say, UV-C causes permanent blindness. A.

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Changing VGA ROM Fonts

Posted on 2020-07-17, 09:18

by

by ALEKS

in Marvin \ Video

in Marvin \ Video

Hi, I wanted to share another project of mine. This time, replacing the VGA ROM Fonts on a Tseng Labs ET4000 ISA card. In short I wanted to replace the boring modernish ROM font on my card with custom ones made from a combination of old ATI fonts and my own touches. I am spending quite some time in …

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Re: ISA I/O Interface

Posted on 2020-06-08, 05:44

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

pentiumspeed , the substrate is 190Tg (glass transition temperature) FR408-HR with a dielectric permittivity of 3.69 at 1 GHz. The solder pads finish is electroless nickel immersion gold (ENIG). I'd say these PCBs are of very high quality. I didn't use capacitors near the ISA supply rails because …

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Re: ISA I/O Interface

Posted on 2020-06-07, 21:03

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I haven't thought about making this a kit, yet. Sourcing some of the parts involve patience and eB*y digging. Take the parallel port controller for instance. Of course there are a couple of sellers in China that offer this chip but it takes a lot of time for it to arrive from China (about 1 month or …

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Re: ISA I/O Interface

Posted on 2020-06-07, 20:26

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes, it's 4 layers, all traces manually routed. Inner planes are ground and power. I know I could've reduced costs and board real-estate with SMD parts. But I went a no cost savings way on this design as it's something I wanted to do for a long time. Back in the early 1990s if I only had something …

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Re: HWiNFO for DOS resurrected !

Posted on 2020-06-07, 18:18

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks, Martin! I named it simply: ISA I/O Interface And model number: 2486-IOIF-301 (just for the fun of it, the project is on my site at: http://www.alexandrugroza.ro/microelectronics/system-design/isa-io-interface/index.html ) Since I won't be designing any other IDE or I/O controller anytime …

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Re: ISA I/O Interface

Posted on 2020-06-07, 18:08

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks! Originally, I wanted to attach only IDE hard disks to it. But when I finished the interface and connected the drives and heard the noise of 4 spinning disks... I reconsidered my approach. So now I am using some cheap eBay CF to IDE adapters that are mounted in 3.5" bays, just as ordinary …

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Re: HWiNFO for DOS resurrected !

Posted on 2020-06-07, 15:50

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I am attaching my own ROM for the controller above. It is an 8 K ROM. However at the moment it is not completely finished. I still need to finalize the INT 13h drive accessing interrupt service routines and I still have about 50% of the ROM capacity available. The ROM BIOS text-mode UI is done …

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ISA I/O Interface

Posted on 2020-06-07, 15:29

by

by ALEKS

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, I've been working on a DIY ISA I/O Interface for some time. I'm not sure whether this project presents any interest but I thought about sharing my work with other retrocomputing fellows out there. These were my initial constraints for this design: * One Floppy Disk Drive Controller with two …

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