The First Personal Computer: A Look Inside the Machine That Started It All
When we think about the first personal computer (PC), we’re talking about the shift from massive, room-sized systems to a machine that a person could use at home or in a small office. That transition happened in the 1970s—and while many machines were experimental or hobbyist-built, one brand marked the official arrival of the personal computer era.
💡 What Was the First Personal Computer?
The title of first commercially available personal computer widely goes to the Altair 8800, introduced in 1975 by MITS (Micro Instrumentation and Telemetry Systems).
However, the first successful personal computer brand to gain global recognition was the IBM 5150, released in August 1981—commonly referred to as the IBM PC.
🔍 IBM 5150: The First True Personal Computer (1981)
Here’s a breakdown of its original hardware components:
| Component | Specification |
|---|---|
| Brand/Model | IBM PC 5150 (Released August 1981) |
| CPU | Intel 8088 @ 4.77 MHz (16-bit external bus, 8-bit internal) |
| RAM | 16 KB base (expandable to 256 KB on motherboard, up to 640 KB with expansion cards) |
| Storage | No HDD (early models); optional 5.25" floppy drives (160 KB single-sided, 360 KB double-sided); later 10 MB HDD (XT models) |
| Display | MDA (Monochrome, 80x25 text) or CGA (320x200, 4 colors; 640x200, 2 colors) |
| Ports | Cassette port (early models), serial/parallel (via expansion cards) |
| Expansion | 5 ISA slots (8-bit); used for memory, graphics, storage, or networking |
| Network | Not included; 10BASE2 Ethernet cards (third-party, added via ISA slot) |
| OS | IBM PC DOS (Microsoft MS-DOS), CP/M-86 optional |
| Power Supply | 63.5W (early models), insufficient for HDDs without upgrades |
| Dimensions | 19.5" x 16" x 5.5" (50 x 40 x 14 cm), ~25 lbs (11.3 kg) |
| Price (1981) | $1,565 (16 KB RAM, no floppy) → $3,000+ (fully configured) |
At launch, the IBM 5150 had no built-in network card or Ethernet port, as home networking wasn’t common. Connectivity was mainly through floppy disks, serial ports, or modems. Ethernet cards would become available later through expansion slots.
🧠 Did You Know?
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The Intel 8088 CPU was chosen over the more powerful 8086 because it was cheaper and compatible with 8-bit components.
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IBM partnered with Microsoft for the operating system, which became MS-DOS 1.0—a huge moment in tech history.
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The IBM PC’s open architecture led to the rise of “IBM-compatible” clones, accelerating the PC revolution.
📈 How Does It Compare to Today’s PCs?
| Feature | IBM 5150 (1981) | Modern PC (2025) |
|---|---|---|
| CPU | Intel 8088 @ 4.77 MHz | Intel Core i7/i9, AMD Ryzen @ 3+ GHz |
| RAM | 16 KB – 640 KB | 16 – 64 GB DDR5 |
| Storage | 160 KB floppy / 10 MB HDD | 1 TB NVMe SSD and beyond |
| Network | None or 10 Mbps Ethernet card | 1–10 Gbps Ethernet / Wi-Fi 6 & 7 |
| Display | Monochrome or CGA | 4K+ HD monitors, multi-display setups |