Re: How about a MR-BIOS ROM file repository?

Posted on 2024-11-25, 08:16

by

by TheMobRules

in Marvin \ Software

in Marvin \ Software

Not sure if it's allowed to post eBay links, but there's a Gigabyte GA-486VS board currently on sale in the UK which has a SiS471 Mr. BIOS from 1997 (there are screenshots included in the listing): https://www.ebay.co.uk/itm/186770308139 If someone ends up buying this board, please dump the BIOS and …

---

Re: 386 battery issues?

Posted on 2024-11-22, 04:41

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Those chips with internal batteries are pin compatible with regular RTCs, so it is possible someone did use one as a replacement when the original barrel battery expired as DaveDDS said. Also, I have a Biostar 486 board from that era that came from factory with a Dallas RTC but the board still has …

---

Re: 386 battery issues?

Posted on 2024-11-22, 01:06

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

My 5.25 inch A: drive settings are retained though. I think that 5.25 inch setting for the drive A is just the default, so it's definitely not remembering any settings. I found your board on TheRetroWeb. It's a Biostar MB-1316VST-SX : https://theretroweb.com/motherboards/s/biostar-mb-1316vst-sx I …

---

Re: Online account craze

Posted on 2024-11-22, 00:26

by

by TheMobRules

in Milliways

in Milliways

Of course they need an online account, how else are they supposed to track every single thing you do without it? The one that pisses me off the most is Microsoft trying to prevent Windows users from creating a local account on their own computers. Isn't the ungodly amount of bloat and telemetry that …

---

Re: 386 battery issues?

Posted on 2024-11-21, 23:39

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

1. Upon boot there is a memory check, and reports '1664 kb ok' - I have 2 x 1mb simms in there, so this seems off This is probably OK, sometimes the BIOS does not report the 384KB of memory between 640KB and 1MB (High Memory Area) depending on how certain settings are configured (such as ROM shadow …

---

Re: Games where the definitive entry to a worthy Trilogy is still missing ...

Posted on 2024-11-16, 16:49

by

by TheMobRules

in Milliways

in Milliways

Knights of the Old Republic 3. The refusal to make a proper 3rd entry to this series is perplexing to me. There was a lot of demand for it, the developers wanted to do it but as usual the executives had to jump on the bandwagon and we got an MMO instead.

---

Re: What voltage regulator to use for this board (EFA P54CNPCI) UPDATE: Vin and Vout are shorted to each other; not sure

Posted on 2024-11-14, 05:02

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Huh, so I was looking at the datasheet for your UMC L2 cache chips (attached below) and it seems they use a 5V power supply but they can interface with a 3.3V bus. So it seems a different design when comparing with my Soyo 029C2 which uses Alliance AS7C3256 SRAM chips that use a 3.3V supply. Good …

---

Re: What voltage regulator to use for this board (EFA P54CNPCI) UPDATE: Vin and Vout are shorted to each other; not sure

Posted on 2024-11-14, 01:30

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Can you try removing the cache chips and see if the short from Vcc to 5V persists? At least on my Neptune boards these are 3.3V chips that are powered by the same rail as the CPU. Maybe one of those went bad and is causing the problem. I believe the 430NX chipset does use 3.3V for some signals but …

---

Re: What voltage regulator to use for this board (EFA P54CNPCI) UPDATE: Installed regulator, outputting wrong voltage?

Posted on 2024-11-13, 22:14

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I also acquired a 3.3V fixed regulator, so I'm wondering if I could modify the circuit to use that instead. Yes you can! Of the resistors that adjust the output voltage (R182, R183), remove the one that connects to Vout and replace the one that connects to ground with a 0 ohm resistor (aka just a …

---

Re: What voltage regulator to use for this board (EFA P54CNPCI) UPDATE: Installed regulator, outputting wrong voltage?

Posted on 2024-11-13, 19:33

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yeah, if it's from DigiKey it should be legit. If you have some resistors and a couple of caps you can test the regulator on its own, there's a simple example circuit on the datasheet. I would try to remove the regulator and check if pins Vin and Vout are shorted on the board. Also, there could be a …

---

Re: What voltage regulator to use for this board (EFA P54CNPCI / Intel 430NX)?

Posted on 2024-11-13, 19:14

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Weird... only thing I can think of is the regulator output being shorted to the +5V input on the motherboard itself. Some 486 boards with voltage autodetection do this to switch between +5V and +3.3V depending on the VOLDET CPU pin, but it doesn't make much sense on a Socket 5 board. If it's not …

---

Re: What voltage regulator to use for this board (EFA P54CNPCI / Intel 430NX)?

Posted on 2024-11-13, 05:17

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The three holes (from left to right in your picture) should be Vin, Vout and GND (in case of a fixed reg.) or ADJ (if it's the adjustable version). So it should be easy to check if the third pin is connected to ground or not. If it is intended for and adjustable regulator that pin should be …

---

Re: ASK M1487/89 - No L1 cache

Posted on 2024-11-08, 22:59

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Not sure if the P24D jumper settings are fully compatible with DX4, even Intel WB-enhanced ones. Usually there are some differences. You should set the jumpers for the AMD DX4-120SV8B (which is labeled 'DX4-120V8BS' in the jumper sheet), but keep the bus speed at 33MHz so it runs at 100MHz. The …

---

Re: STB Powergraph C33 Card Only Displaying Black & White?

Posted on 2024-11-06, 00:06

by

by TheMobRules

in Marvin \ Video

in Marvin \ Video

I had the same problem with a Trident ISA card. The cause of the issue is as follows: originally, pin 12 on the VGA connector, also known as ID1 , was originally used by the card to detect the type of monitor connected to it. Color monitors left this pin unconnected and the card would work in the …

---

Re: Found a NOS treasure trove...maybe

Posted on 2024-11-05, 05:05

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I think I have my project for the coming holidays 😀 Hopefully, my meager soldering skills will be adequate, at least it's old enough it should still be SnPb. The last thing I recapped was ROHS and it took me like 4 hrs to replace 6 caps. It'll be fine, these units are from the pre-ROHS era, and …

---

Re: Is Pre-emptive Tantalum capacitor replacement recommended?

Posted on 2024-11-04, 02:17

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

As you have noticed, most of the time tantalum failures occur with 16V rated capacitors on either the 12V or -12V lines. Those are the only cases I would consider for preemptive replacement with 25V caps, mostly on 80s or early 90s stuff which is where the explosions usually happen (IBM stuff in …

---

Re: Bought these (retro) hardware today

Posted on 2024-11-03, 22:25

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Nunoalex wrote on 2024-11-03, 22:07: unisound doesn't seem to detect it either it is not PnP or it is not working It's from early 1994, I don't think it's PnP. You can try cleaning the contacts, some of them look kind of corroded.

---

Re: Creative Labs Disk ID to Model number correlation?

Posted on 2024-10-31, 21:55

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'd also like to have this info, like a map between card model number and CD (or floppy) disk IDs. For example, I have a CT3930 which is a SB32 but it's also a Vibra and is non-PnP which doesn't seem to match with any of the driver distributions out there. So I've always been curious about what set …

---

Re: MT-32 front panel button replacements

Posted on 2024-10-29, 23:06

by

by TheMobRules

in Marvin \ Sound

in Marvin \ Sound

According to MT-32 service manual schematic, there is 1S2473 diodes before every switch, may be you measured with them? In the schematics it is just a switch, desolder the working one and check it separately. If it measures (desoldered) some kOhms - it's not normal. Edit: there is video on youtube …

---

Re: Found a NOS treasure trove...maybe

Posted on 2024-10-28, 05:56

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have one of these, I also got it NOS. They are well built (manufacturer is CWT as mentioned above), but you definitely want to replace ALL the capacitors as they used Fuhjyyu, which are of abysmal quality. Other than that they should be more than enough for any AT build you have. As for the extra …

---