Re: Artifacts on S3
Posted on 2023-01-17, 20:19
AlessandroB wrote on 2023-01-17, 13:12: I have found two of this... are useful? The digit "8" in the end indicates 80ns. I would recommend against soldering those to the board as replacement.
Re: ISA Graphics Cards - need solid advice inbetween all the confusing scene
Posted on 2023-01-14, 10:24
Basically Oak, Realtek and Trident are known as slow ISA graphics cards. That's true. Nevertheless, Trident improved over time, but they were bad at marketing. Trident has two notable non-accelerated series of SVGA graphics chips: The original TVGA8900 and the cost-reduced TVGA9000 series directly …
Re: Opl3 and ESS FM on one card. Does it exist?
Posted on 2023-01-14, 10:11
DundyTheCroc wrote on 2023-01-14, 09:51: Maybe Compaq ESS Audio Feature Board with ES688F+Opl3? Good idea, but the ES688 did not yet implement ESFM.
Re: failed memory channels in 486 motherboards
Posted on 2023-01-14, 10:10
Thank you for your help on this. Sure enough, there was a broken trace on the back of the board. I did a trace repair and now the board is working perfectly. Great that you could fix that board! If you want it to look more pretty, you can remove the flux residue (that's the transparent gunk at the …
Re: 486 bus at 40 or 50mhz, isa bus?
Posted on 2023-01-13, 19:52
I dis not see anithing like you said You must look in the BIOS. It is a BIOS setting, not a jumper setting. Some boards do not expose the ISA clock divider in the BIOS setup, but rely on auto configuration. In that case, the BIOS measures the processor frequency during POST, and calculates the FSB …
Re: VLB video card memory
Posted on 2023-01-13, 19:49
2nd MB would only enable support of 1024x768 with 64k colours instead of 256 and 1280x1024 with 16 colours. However, both with unusable interlaced refresh rates (due to slow RAMDAC) which look ugly on CRT and rarely work with LCD screens. So there is no point. [...] So save the hassle. I agree with …
Re: 486 bus at 40 or 50mhz, isa bus?
Posted on 2023-01-13, 19:32
Incidentally, 486-class motherboards run the CPU at the same frequency as the System Clock - they can do this because they use both edges of the timing signal, which is a square wave. As far as I know, the explanation why 486 CPUs work on 1x CLK (instead of 2x CLK as the 286 and 386) is wrong, …
Re: PS/2 Model 30 Floppy Drive problems - is it the floppy drive controller?
Posted on 2023-01-13, 19:15
No third hand. Use the two irons as tweezers to pick up the component. Of course, this also exists as professional tool, called "desoldering tweezers". After some research I ended up ordering one of these hot air stations: https://www.amazon.com/dp/B08VNYPL7H?psc=1&ref=ppx_yo2ov_dt_b_product_ …
Re: Let's fix some PS/2 floppy drives!
Posted on 2023-01-12, 20:01
The model 30 uses slightly different memory layout than standard PC. Here is an explanation and a conversion instruction: http://john.ccac.rwth-aachen.de:8000/misc/ps2cache/ That document refers to the IBM PS/2 Model 30 286. I checked the schematics of the IBM PS/2 Model 30 (non-286), and those …
Re: OPTi 82C930 review
Posted on 2023-01-11, 18:57
Indeed, the Win9x drivers are very basic. This card came out in the early months of 1995, and the latest Win9x drivers that I found were from 1996. It's no big surprise that DirectSound support is lacking, since DirectX was still in its infancy back then. Did you ever try to manually force the …
Re: Add -5V directly to ISA pin B5 - is it safe?
Posted on 2023-01-11, 18:53
My question is , can I take -5V directly from my PSU, and connect it to the B5 pin on ISA? Is it safe, or do I need something inline with that? It is safe. -5V is often the least powerful supply rail anyway, and you usually don't have anything in line with all the other lines, like the +5V line ( …
Re: failed memory channels in 486 motherboards
Posted on 2023-01-11, 18:46
my pics were confusing and I did that poorly. the front and back did of the modules did not properly correlate. the inserted photos below properly correlate to the front and back of their respective module. one photo is one module, the other photo is the other module. OK, I get it now. I could have …
Re: failed memory channels in 486 motherboards
Posted on 2023-01-11, 06:46
I di try a single 4MB module to no luck. See pic for the modules I tried. They are the only 4MB modules I have. Maybe there is something about them that make them incompatible? The first and second module don't include parity bits. This might be a problem, depending on the board. The last one is …
Re: PS/2 Model 30 Floppy Drive problems - is it the floppy drive controller?
Posted on 2023-01-10, 18:57
Very interesting idea. How are you actually removing the component though, seems like you need three hands - two for the irons and one to pull on the cap? No third hand. Use the two irons as tweezers to pick up the component. Of course, this also exists as professional tool, called "desoldering …
Re: PS/2 Model 30 Floppy Drive problems - is it the floppy drive controller?
Posted on 2023-01-09, 18:49
Still no luck with the drive I repaired. So I did the reasonable thing and said fuck it, and took the second drive apart. This time I recapped just the motor PCB not the controller one. The caps obviously had leaked. Man am I really just this bad at desoldering these surface mount components or is …
Re: ECS Local Bus VGA card artifacting
Posted on 2023-01-08, 13:30
Yes, I definitely intend to do this! Currently I have mapped all 32 data pins, plus a few VCC/GND/NC. I still need to work on the address lines and whatever else I can find. Some early local busses only go up to A25 (like the Opti Local Bus) , so don't try for too long to search for high address …
Re: ECS Local Bus VGA card artifacting
Posted on 2023-01-08, 00:01
pentiumspeed wrote on 2023-01-07, 23:57: Use thin wire. Do you have motherboard picture posted? The board model was mentioned in the original post. It's https://theretroweb.com/motherboards/s/ecs-sl-486e
Re: ECS Local Bus VGA card artifacting
Posted on 2023-01-08, 00:00
The good news is that the video card is probably fine. First of all, mkarcher you were absolutely right regarding how the data lines are handled. With a multimeter and some patience, I traced all 32 data lines from the ET4000AX chip to the F245 chips and finally to the ECS Local Bus (let's call it …
Re: Recommended 16-bit DOS compressor?
Posted on 2023-01-07, 21:01
LHA, ARJ and PKZIP 2.x are based on the same ideas and perform similar (all are based on a huffman encoding of the output of a LZ77 compressor with a sliding window. The window size is around 32 kilobytes). It might be a good idea to look at all of them to experience the command line interface, or …
Re: Memtest86+ v6.00
Posted on 2023-01-07, 17:30
Sphere478 wrote on 2023-01-07, 17:22: Is there a image I can use with gotek? Do I just rename the iso to img? Extract boot\floppy.img from the .ISO, and put that on your gotek. On Windows systems, you can use 7-zip to extract files from an ISO image, or you can mount it in more recent Windows …
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