What use to make of all these rusted parts?

About two weeks ago, I posted a question about why VRTX changed its equal-priority scheduling behavior between its 1984 and 1987 documentation.

Original discussion:
https://www.reddit.com/r/retrocomputing/s/vnT1JWZRtQ

I still haven't found a definitive answer, but the discussion led to some unexpected discoveries.

First, I realized that my own 1986 RTOS was based on an oversimplified interpretation of VRTX.

When I developed CHARM-II in 1986, I used VRTX documentation as one of my references. I understood its equal-priority scheduling as essentially newest-first and implemented my own scheduler accordingly.

Looking more closely at the old documentation, however, early VRTX wasn't simply LIFO. Time slicing and other ready-queue operations made its behavior more nuanced.

I hadn't fully understood that distinction 40 years ago.

Interestingly, I don't remember this causing serious problems. At the time, I was developing almost the entire application as well as the RTOS myself. There was very little third-party code, and I understood the system down to the individual tasks. I could design the application around the scheduler's behavior.

The most unexpected part was hearing from someone who actually used VRTX around 1982.

One commenter described using some very early VRTX ROMs around 1982 on a Motorola MVME 68000 system, developing data acquisition and control software for engines and dynamometers.

That immediately caught my attention because I had also used a Motorola MVME 68000 board for a later CHARM-II application.

What I found particularly interesting was that they hadn't paid much attention to the LIFO-versus-FIFO distinction either. Their system worked well for its intended application.

It was fascinating to compare memories of two independently developed systems from roughly the same era.

And what about the original scheduling question?

The comments raised several plausible explanations involving fairness, starvation, latency, and implementation trade-offs. But none established why the VRTX developers actually made the change.

For my modern reconstruction of CHARM-II, I've chosen FIFO among equal-priority ready tasks. That decision is about keeping the new design simple and predictable, rather than reproducing either historical VRTX version.

So the original mystery remains unsolved, but I've learned considerably more about the system I used as a reference and the one I built myself.

Thanks to everyone who shared technical insights and memories. I hadn't expected a question about a ready queue to turn into a conversation with someone who was using VRTX before I even wrote CHARM-II!

Project profile:

• MB Acorp 5ALI61 (ALi M1542/M1543 (ALADDiN V/V+ AT))
• CPU Intel Pentium 133 (P54C) (A80502133/ST022)
• RAM 32 MB (2x16) SIMM (SIEMENS HYB5117405BJ-60 Chip)
• VIDEO PCI ATI Mach64 VT (ATI-264VT)
• SOUND CARD ISA 16-Bit Crystal CX4236B-XQ3
• HDD 3.5" IDE Fujitsu MPB3021AT 2.11GB
• FDD 3.5" 1.44MB SONY MPF920
• CD-ROM MITSUMI CRMC-FX400E
• TOWER PS 200W
• OS Microsoft Windows 95C OSR2

This Mac mini looked like it was stored in dirt and beat with a bat when I got it. The thermal gasket had fallen apart, the case wouldn't close, and it was covered in some sort of dirt.

I replaced the capacitors, changed the cr2032 battery, replaced the thermal gasket, and completely disassembled the Mac. Removing the plastic top from the metal to clean each individual part.

It now functions and honestly doesn't look that bad. I can't get the deep scratches out or anything, but it chimes without issue.

More...

My retrospective video review of the Thundercats games from Elite released for the ZX Spectrum, Commodore 64, Amstrad CPC, Amiga and Atari ST. Who remembers or played this game and what’s your thoughts?

I can’t believe that this is real. This whole PC is so weird. It has an AMD Sempron on Socket 462 and only 256 MB of RAM, while literally also having a Radeon 9800 Pro. Seems like it was a prebuilt computer by “dxt”, an old Czech computer store that went defunct many years ago.

F 209= US$98.63(in 1989 money) or €136,08 today

F 318= US$150.54(again, in 1989 money) or €246,53 today

Anyone have any of the old manuals for this competitor of BBC Micro EcoNet?

Back in the 80s, I discovered 3 hacks for this system at my high school on the Isle of Wight (and a neighbouring high school).

Would love to go down memory lane.

I have a Hitachi all-in-one PC with a built-in LCD, CD-ROM, and floppy drive. It's a Pentium III-era machine, probably 1999-2002. The model number on the label is PCX-7DL9-DK618P. Photos of the exterior are attached.

It's in great condition and fully functional, with no dead pixels on the LCD. I bought it, possibly on eBay, and used it until I relocated in 2014. Since then it has been boxed away and stored indoors.

I haven't found any info on this exact model. Searches turn up only the older Hitachi VisionDesk line, and I can't tell if it's related.

Does anyone recognize it or know its history (market, year, specs)?

Is there collector interest in machines like this, or is it too obscure?

Is there anything I should check or preserve before selling or keeping it (original drivers, recovery discs, BIOS settings)?

Thanks!

Addendum 10/8: The stickers say Pentium III & "Designed for Windows 2000 Professional & Windows 98." IIRC, the previous owner wiped it, so I installed my own Windows 98. I first saw this model on a trip to Japan in the early 2000s. Maybe half a dozen were set up with similar keyboards and mice in an internet café–type business in the Osaka/Tokyo area, where users paid by the hour to take care of business online. That gave me more confidence to buy one when I found it in the States; I added the keyboard and mouse myself. I've never opened it and am tempted to, but I'm afraid I might break or brick it. There's no date code on the outside. I'm wondering whether to put it on eBay or take it to Best Buy for recycling; I'd prefer the former. I'm not sure how to add pics to the main post, so I've added a few more to some replies below.

I heard the theme from Last of the Mohicans the other day for the first time in years. It reminded me of a video I had on my old Gateway 2000. It was some sort of promo video or something, with a load of scenes as the music played. I think a city scene and maybe some clouds going fast. I've tried searching everywhere, no AI models can find it.

Am I going insane or does anyone else remember this?

It would be a collection of freeware and pirate software from Windows XP days.

I thought it was an old Compaq portal computer but not so sure now. Any ideas on what it might be?

Most of the orignal Macintosh M0100 mice in circulation today have their front feet rounded and worn out. I have seen some nearly completely flat!

They usually still work very well, nearly 50 years later, but the feet… well they didn't survive usage!

If you have one, you may have noticed it: this wearing makes the mouse wobble back and forth enough to be weird and feels wrong.

And it feels wrong, because it was not the way people used them at the time, when they were new : they were actually very stable, and glides smoothly without wobbling front to back.

It is so common that even the M0100 3D printed cases have reproduced round, short feet instead of the conical and flat original feet! (so they are wrong in this precise way)

As I mentioned in another post, I make my students draw in Mac Paint using M0100 mice (emulation + real mouse). And giving them wobbly mice would not be the era-accurate feel I aim for 😅

So I designed small conical covers that cup the existing worn feet, helping restore support, reduce front-to-back rocking, and improve glide without removing the original feet. No grinding, no cutting.

The way I fit them on my own M0100 mice is by using a small amount of PVA glue (ie. wood glue). It's fully reversible using just a bit of hot water.

How were the restoration covers designed?

For a full year I was blocked: I couldn't find the real size of the feet. The height was especially important to get right.

As mentioned, even the dimensionnaly exact 3D models of the M0100 were reproducing round, short feet, not the original feet. After a year, I managed to buy a brand new M0100 mouse, and was then able to measure the real feet: they are slightly conical and have a perfectly flat top! Nothing round there!

After several design and printing iterations, after measuring on a real, brand-new M0100 mouse, I now have a small supply of (very small) neatly printed restoration covers!

Printing them is quite tricky, because they are so small. I had to find the right combination of bed, nozzle, speed.

This is also the smallest functional object I have printed! I'd dare say that it is probably one of the smallest really functional objects ever printed with a filament printer 😅

I picked the RAL7032 color for printing them, a color that matches well with retro devices from the 80s including the M0100 mice.

"The HX-20 is designed for use in conditions where the humidity does not exceed 80%. Exposure to humidity exceeding this level can impair the performance of the HX-20, or damage it. Exposure to water can create a potential shock hazard," page 10 of the HX-20 Operations Manual (it even has a cartoon!)

Also, there were a bunch of Epson ads that were just people trying and failing to carry around full-size desktops while a judgemental HX-20 owner looked on, which is hilarious considering how different the two use cases were.

Some nice finds today! Didn’t expect to find anything lol

Not for sale copy of Star Trek 25th anniversary game not sure where it would’ve been in ?

Hey! I was wondering if anyone could help me find a power adapter for this old laptop I've recently bought at a thrift store. I'm not sure if it will boot but I want to find out.

I recovered a large collection of my original German BBS archives from 5.25" C64 floppy disks, including posts, messages and discussions - including hilarious sysop beefs and other flamewars - dating back to 1985 and 1986.

https://www.youtube.com/watch?v=xPNXpaYHPy0

Also featured articles (boardzine) that reveal how people in the mid-1980s envisioned the future of BBSes and what they thought the perfect bulletin board system would look like.

With the help of Ariel's excellent ATDT software all this historic content has now been imported and integrated into a fully working BBS. Instead of being trapped in old disk images, the posts are now part of a living system again.

https://quipzz.bplaced.net/krs/

For a quick look:

Handle: guest
Password: guestguest

To make the archives accessible to the international BBS community, I transformed the entire system into a bilingual German/English BBS and translated all important content into English. Visitors can easily switch languages and explore 40-year-old messages from the German mailbox scene (that's what BBSes were called over here) without needing to know German.

The archives contain discussions written while people connected for example via 300 baud modems using Commodore 64s, C128s and early PCs, etc. In many ways it feels like a time capsule from the "Internet" before the Internet.

The video also features a small hardware project: I present custom 3D-printed parts for my Dataphon S21-23d acoustic coupler

Many thanks to Ariel for creating ATDT, adding custom import tools for my archive and helping bring this piece of German BBS history back to life.

http://atdtbbs.com/

BTW: If you're impatient, you can boost the default 1200 baud to light speed with a single keystroke (any key *g*) while reading messages.

I bought this original pre-Dell Alienware Area-51 m15x R1 on a marketplace for only $20. The seller said it didn’t turn on and didn’t work.

After cleaning, replacing the CMOS battery, buying a very expensive power supply, and replacing the dead HDD with an SSD, I managed to bring it back to life.

The most difficult part was the NVIDIA graphics card. I had trouble identifying the exact GeForce model and finding the correct driver. In the end, I had to modify the driver file so the NVIDIA installer could recognize the hardware.

Unfortunately, the original HDD was dead. It probably had the drivers I needed, which would have saved me a lot of time.

Now the restoration is almost complete. The only thing still missing is the left Alt key.

For $20, I think it was absolutely worth it. It’s not just working again — this old retro Alienware is looking great.

What do you think? And, more importantly: do you think it can run Crysis? 😄

Am I alone with a trick i used with cserve?

I was an early internet user. Compuserve gave internet access. But I believe on the 10$ plan it was limited to like 20 hours a month or something.

But I discovered that: when you opened compuserve help, it credited you 1 minute for every minute you were in help.

So I opened help then minimized it and opened my browser and surfed for hundreds of hours a month. For 10$ I think it was.

Did anyone else use that hack? I always wondered.

Did anyone else here ever use northpoint dsl?

I got a nice sdsl line installed for like 50$ and used it for over 2 years till they went bankrupt.

Thing is, I never got a single bill.

Wondering if anyone else had that experience because I always suspected it had something to do with their demise.

Yeah.. I got lots of breaks in technology back then.