Re: Replacing Tantalum (12v/5v rail filters) capacitors with through hole ceramics (not MLCC)?

Posted on 2023-07-26, 11:46

by

by root42

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'd figure that 80s tants that had this problem, were not expected to these to have been run, sit for decades, and then powered on out of curiosity. However, I'd suspect the manufacturers have paid attention to this fault, especially since mil/aero has had similar equipment in service for a long …

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Re: Replacing Tantalum (12v/5v rail filters) capacitors with through hole ceramics (not MLCC)?

Posted on 2023-07-25, 09:09

by

by root42

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There cheap tantalums, cheap MLCCs and there are expensive MLCC and tantalums. If you buy a modern, good brand tantalum, it will hold for decades. And with the better brands they won't fail short either.

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Re: PicoGUS: ISA sound card emulator with Raspberry Pi Pico (Gravis Ultrasound, AdLib, MPU-401, Tandy, CMS)

Posted on 2023-07-24, 17:26

by

by root42

in Marvin \ Sound

in Marvin \ Sound

P.S. PLEASE IGNORE THIS ---> for some reason the old firmware also does not output sound... Maybe the card developed some fault but initialize correctly and passes the ram verification tool I once had one of those I2C DACs with a lost channel - ended up simply being a bad soldering of the connector …

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Re: PicoGUS: ISA sound card emulator with Raspberry Pi Pico (Gravis Ultrasound, AdLib, MPU-401, Tandy, CMS)

Posted on 2023-07-24, 13:44

by

by root42

in Marvin \ Sound

in Marvin \ Sound

Out of curiosity, does PicoGUS get detected as a GUS PnP and run as such in Win9x? Is that eventually in the cards? Asking because I'm not sure whether to plug this into my Cx5x86-120 system (which means I'd have to replace the external MT32-Pi with a McCake, and route the PicoGUS to MK8330's L/I) …

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Re: CT1740 Potentiometer Problem

Posted on 2023-07-24, 11:55

by

by root42

in Marvin \ Sound

in Marvin \ Sound

I have a CT1740, and it has an issue with the volume potentiometer. There is no sound on the right channel unless I wiggle/tilt the potentiometer until there is. I'm guessing some oxidation is at work here, should I just spray some contact cleaner and be done? Or should I completely replace the …

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Re: Gotek woes (32KB) - anyone else?

Posted on 2023-07-24, 08:35

by

by root42

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Maybe it's also because of the quickness of that 286. It runs at 16 MHz (CPU), with everything else at zero wait state. Isn't this detail is abstracted by the floppy controller? The floppy drive itself has nothing to do with the CPU or ISA bus at all. The controller may have issues though when …

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Re: Vogons Video Announcement Thread

Posted on 2023-07-23, 19:47

by

by root42

in Milliways

in Milliways

Game Boy Color: Funny Playing IPS Screen Mod The Game Boy Color was a step up in the evolution of the most popular game handheld. But its screen was still without backlight and rather dim. Nowadays you can have a nice high resolution IPS screen with backlight. Here I show you how to mod the Game Boy …

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Re: Create better compression?

Posted on 2023-07-23, 08:48

by

by root42

in Marvin \ Software

in Marvin \ Software

Well...I'm working on my own compression techniques, and so far, some of my compression techniques are doing much better than 7Zip--even some of my 8-bit compression techniques. However, they are no where near usable yet--I have to start debugging them soon. BTW, I have an early PC version I just …

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Re: Create better compression?

Posted on 2023-07-22, 21:52

by

by root42

in Marvin \ Software

in Marvin \ Software

Can you elaborate a bit of what you did so far? Have you written your own compression algorithm? Are you using off the shelf tools? Do you know there are competitions for most efficient algorithms, like this: https://gdcc.tech/ Also, different algorithms perform different depending on the input. …

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Re: Swedish Sound Blaster 1.5 clone and GUS PnP clone

Posted on 2023-07-21, 21:19

by

by root42

in Marvin \ Sound

in Marvin \ Sound

1strail wrote on 2023-07-21, 15:54: I wondered about the stereo. I thought the older SB 1.5’s were mono, but they clearly have 2 jumpers for amplified vs. line out. I’ll look around for the ready made devices you mentioned. The SAA1099s for C/MS compatibility are stereo.

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Re: PicoGUS: ISA sound card emulator with Raspberry Pi Pico (Gravis Ultrasound, AdLib, MPU-401, Tandy, CMS)

Posted on 2023-07-21, 17:58

by

by root42

in Marvin \ Sound

in Marvin \ Sound

There you go!

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Re: Convert MIDI files to sound correct on a Roland MT-32 compatible device

Posted on 2023-07-21, 12:19

by

by root42

in Marvin \ Sound

in Marvin \ Sound

Have a look here: https://www.midimusicadventures.com/queststud … urce/utilities/ The GM mapping will never be perfect, as the MT32 has too few channels and other limitations, but it will improve your GM playback.

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Re: Paradise EGA Capacitors and Composite

Posted on 2023-07-20, 16:46

by

by root42

in Marvin \ Video

in Marvin \ Video

Wishful thinking question: While I know the RCA ports won't output composite, does the PEGA 1A chip have that ability at all? Could a pin be tapped somewhere to get composite out? I think nobody talked about your composite wish. Composite would ever only make sense in the CGA resolutions of this …

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Re: Sonic Buster 8: A new 8-bit ISA sound card

Posted on 2023-07-20, 10:54

by

by root42

in Marvin \ Sound

in Marvin \ Sound

Hello there! I wonder if anyone with a real OPL3 & DOS & cpu>=486 can tell if Adlib Tracker II needs an opl_latency=1 option to play correctly? I bumped into a problem that OPL3-enabled games I tested (WAR2, Descent, Blood,... ) are all ok, but AT2 plays rubbish if opl_latency is set to 0 (default) …

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Re: Sonic Buster 8: A new 8-bit ISA sound card

Posted on 2023-07-20, 09:42

by

by root42

in Marvin \ Sound

in Marvin \ Sound

Hello there! I wonder if anyone with a real OPL3 & DOS & cpu>=486 can tell if Adlib Tracker II needs an opl_latency=1 option to play correctly? I bumped into a problem that OPL3-enabled games I tested (WAR2, Descent, Blood,... ) are all ok, but AT2 plays rubbish if opl_latency is set to 0 (default) …

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Re: PicoGUS: ISA sound card emulator with Raspberry Pi Pico (Gravis Ultrasound, AdLib, MPU-401, Tandy, CMS)

Posted on 2023-07-19, 11:52

by

by root42

in Marvin \ Sound

in Marvin \ Sound

appiah4 wrote on 2023-07-19, 09:12: Thanks, I will take another look at everything yo said and do continuity checks with the multimeter.. In the meantime, here are better photos of my first attempt at SMD soldering 😅 Looks fine, but the pico pinheader looks a bit sloppy on this area: Filename IMG_ …

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Re: How fast are the fastest 286 Mainboard?

Posted on 2023-07-18, 20:49

by

by root42

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I also try to build a fast 286 rig. Actual config: "PC-CHIPS3" chipset (or something with this sticker on it) mobo, 25MHz Harris CPU, Cyrix 287XL+ FPU, 4MB SIMM RAM, Tseng ET4000W32i videocard, 1.2MB & 1.44MB FDD, Seagate 520MB HDD, Creative Sound Blaster Pro2. Here is a video with some benchmarks …

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Re: PicoGUS: ISA sound card emulator with Raspberry Pi Pico (Gravis Ultrasound, AdLib, MPU-401, Tandy, CMS)

Posted on 2023-07-18, 07:08

by

by root42

in Marvin \ Sound

in Marvin \ Sound

appiah4 wrote on 2023-07-17, 22:17: The Pico in question seems to be a bootleg, not a genuine.. Judging from your photo the pico looks pretty genuine to me. Why do you think it isn't?

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Re: PicoGUS: ISA sound card emulator with Raspberry Pi Pico (Gravis Ultrasound, AdLib, MPU-401, Tandy, CMS)

Posted on 2023-07-18, 07:04

by

by root42

in Marvin \ Sound

in Marvin \ Sound

One interesting failure mode is if IOCHRDY doesn't work - root42 ran into this on a stream of his where he was building a PicoGUS. AdLib firmware worked fine for playing music, pgusinit was not working reliably, and GUS emulation didn't work at all. He had a teeny tiny solder bridge on U9, the chip …

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Re: Vogons Video Announcement Thread

Posted on 2023-07-09, 18:25

by

by root42

in Milliways

in Milliways

Our First PC: Highscreen Colani 486SX The first PC that our family bought back in 1993 was a Vobis Highscreen Colani 486SX-25 Desktop. It was a rather run-of-the-mill low end 486, but it had one special feature: the faceplate of the case was designed by famous industrial designer Luigi Colani. With …

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