u/Emil_Cvetanski

From 30-pin SIMMs to 72-pin EDO RAM. A small look at the evolution of memory in the mid-90s, when every megabyte cost a small fortune.

This is the Преброител П1 (Counter P1), a Bulgarian-built scientific instrument manufactured by РП Електроника. It was designed to count electrical pulses from detectors and was commonly used in nuclear physics laboratories and radiation measurements with Geiger-Müller tubes and scintillation detectors.

Under the main CPU, you can also spot an empty footprint for a directly soldered PQFP 486 processor — basically the hardware equivalent of the "you are broke" blank buttons on base-model cars.

The PCB was designed to support a socketed PGA 486, a soldered PQFP 486, or even both at the same time, depending on the manufacturer's configuration.

This Soviet vacuum-tube instrument from 1958 was designed to detect radioactive contamination using external probes. It measures radiation pulses, displays the count per minute, and even provides a simple status indication: Clean, Ready, or Dirty.

Inside are vacuum tubes, transformers, relays and beautifully hand-wired circuitry — a example of 1950s Soviet engineering.

The Dell Inspiron 8200 wasn't just a high-end laptop—it was built to replace a desktop. With desktop-class performance, a 1600×1200 UltraXGA display, nearly every port you could ask for, and Dell's modular Media Bay, it was one of the most capable portable workstations of its time.

The CPU that changed everything. AMD Athlon didn't just challenge Intel—it became the first mass-market 1 GHz x86 processor, beating Intel by two days and changing the CPU market forever.

А look inside the AI-128-2 – a Soviet nuclear pulse analyzer from 1970. This is what brutal analog science looks like!

This is the 21" Apple Studio Display (M4868) from 1999. Nearly 40 kg of Trinitron goodness, built for graphic design, Photoshop and prepress at a time when 1600×1200 was considered high-end.

Fun fact: Despite the official 1600×1200 specification, I tested mine at 1920×1080. It works correctly,needs only minor geometry adjustment using the front controls.

And of course... it's also well known for its infamous flyback transformer failures.

Someone I had never spoken to before tipped me off about a pile of old computers in Sofia. Nearly 2,000 km away, but one phone call was enough to arrange everything. A few hours later, they were picked up and waiting for me.

I opened it up for a closer look at the internals, including the PowerPC G4 CPU module, ATI graphics card, and the iconic swing-open case design. Over 25 years later, it's still one of my favorite computer designs ever made.

The Intel Pentium II was one of the most desirable CPUs of the late '90s. Its iconic Slot 1 cartridge and massive heatsink made it instantly recognizable. Also shown is a Socket 370 → Slot 1 adapter (slotket), allowing many Celeron and Pentium III CPUs to run on compatible Slot 1 motherboards.

Some physical copies from my own collection and a mix of interesting XP history.

Rocking a Mobile Pentium 4-M and that ahead-of-its-time 15" UltraXGA (1600x1200) 4:3 display. Back when most desktop CRTs were running at lower resolutions, this monster.

Just sorting through my collection and had to share this lineup. A legendary era of 3D gaming. Who else remembers the VGA pass-through cable? What was your first 3dfx card?

A closer look inside the Power Mac G4. Internals, CPU daughterboard, ATI Rage graphics card, and a final shot with the 21" Apple Studio Display.

A few weeks ago I posted my Olivetti M24 on Reddit.

I received a comment from someone who mentioned they had the original documentation.

A few days later, that complete stranger tracked me down from Reddit to Facebook and offered to send me this archive.Today it arrived from Netherlands.

Original Olivetti technical binders, hardware architecture manuals, ROM BIOS listings, circuit diagrams, service documentation, MS-DOS and GW-BASIC manuals, original software disks, and diagnostics.

Huge thanks again to u/TriggerFish1965, who chose to send these to me instead of throwing them away or selling them. This kind of computing history deserves to be preserved.

Interesting feature: Resume Mode let you pick up exactly where you left off, skipping a full MS-DOS reboot.

The last three photos are custom information cards I created to provide more details about the machine.

Unfortunately, this machine is completely dead. I'll be tearing it down soon and attempting a full restoration.

Edit: This is the 8051A model.

3484 RPM spindle speed, an unusual voice coil design, factory defect tables, and of course the infamous "brick your drive" story.

Today I'll show you something a little different. This is one of the groups I'm a member of (a Bulgarian scrap metal group on Facebook).

Some of these machines are already part of my collection. I originally posted this in another community, but since I'm not sure how much the audiences overlap...I thought I'd share it here as well. Hopefully it's worth a look.

Today I wanted to show you something a little different.

This is one of the Bulgarian precious metals recovery groups I'm a member of — often the last stop for many pieces of hardware before they disappear forever.

Every day, old computers, laboratory equipment, telecommunications gear and industrial electronics arrive here to be dismantled for their gold and other valuable metals.

A few machines from photos like these have already made their way into my collection before it was too late.