The Golden Age of IBM PCs

CPU: 4.77MHz Intel 8088
RAM: 16K-256K (640K with expansion card)
Price: $1,565-$4,500 (about $4,700-$13,450 today)

IBM intended its PC to compete with everything from the upper-end of the home market (where the Apple II ruled) to the small business PC realm. To that end, it allowed maximum flexibility: its base model contained only 16K of RAM and no disk drives (users could run BASIC from ROM and save to a cassette tape drive). Maxed out, it could utilize a whopping 640K of RAM, two double-sided, double-density disk drives (360K storage each!), and color CGA graphics. That configuration would cost you as much as a new car at the time. Still, this flexible machine became the forefather of all x86 PCs today.

CPU: 4.77MHz Intel 8088
RAM: 128K-640K
Price: $7,545 for 10 MB HD, disk drive, CGA (about $22,551 today)

IBM aimed its pricey-but-capable PC follow-up, the PC XT (5160), mostly at small businesses. Unlike the original PC, it included a 10MB hard disk and a 5.25-inch double-density disk drive as standard features, which explains its high price. It also upped the five ISA expansion slots of the original PC to eight and eliminated the cassette drive port. Around this time, other firms began producing IBM PC clones in earnest, often copying the XT architecture.

CPU: 4.77MHz Intel 8088
RAM: 256K - 640K
Price: $4,225 (about $11,155 today)

The Portable PC (5155) packed a desktop-sized IBM PC motherboard (albeit with eight instead of five ISA slots) into a large suitcase-sized package that also incorporated a full-sized keyboard, a 9-inch amber display, and two 5.25-inch floppy drives. The entire assembly, which could be carried with a built-in metal handle, weighed about 30 pounds. Despite being labeled "portable," the 5155 still needed a wall outlet for power. But it did pack a lot of capability into a small space for the time.

CPU: 4.77MHz Intel 8088
RAM: 64K - 512K
Price: $1,269 for 128K and floppy drive, no monitor (about $3,792 today)

In its quest to win over the lower-cost home PC market, IBM produced an awkward, hamstrung machine in the PCjr that suffered from an uncomfortable keyboard, a strange sidecar expansion method, limited IBM PC compatibility, nonstandard I/O ports, and other oddities (it's the only IBM PC with a cartridge port). At the same time, the PCjr did include expanded graphical (color-wise) and sound capabilities over the original PC that lent themselves to better gaming experiences. Ultimately, the machine flopped, but not before inspiring a much more successful rival: The Tandy 1000.

CPU: 6 or 8MHz Intel 80286
RAM: 256K - 16MB
Price: $4,000 - $6,700 (about $11,955 to $20,000 today)

The IBM PC/AT (5170) represented the first architectural upgrade to the IBM PC platform, introducing Intel's new 80286 CPU, allowing for vastly more RAM, a new keyboard standard, a 1.2MB high-density floppy drive, larger hard disks, a ROM BIOS, and more. Like the PC and XT before it, it inspired a large industry of copycats that kept much less expensive AT compatible machines on the market for many years—even after IBM had stopped selling them.

CPU: At launch, Intel 8MHz 8086, 10MHz 80286, 16 or 20MHz 80386
RAM: 640K - 16 MB (depending on model)
Price: $2,295 - $10,995 (about $6,859 to $32,863 today)

After the success of the PC/AT, the clone market began to grow rapidly out of IBM's control. To reassert its leadership, IBM released the PS/2 series of machines in 1987. It consisted originally of five models (30, 50, 60, and two 80s) that ranged from an 8086 machine (the Model 30) up to a whopping 20MHz workstation-class 80386 beast (the 80-111). Among other innovations, the PS/2 line introduced 3.5-inch floppy drives into the IBM pantheon, PS/2 keyboard and mice ports, VGA graphics, and the poorly received Micro Channel bus architecture. These drastic changes were out of step with the burgeoning clone market, and while a modest success, the PS/2 line further eroded IBM's control of the platform it had created.

CPU: 10MHz Intel 80286 (Model 2011)
RAM: 512K - 1MB (Model 2011)
Price: $999 - $1,999 (about $2,985 to $5,975 today)

At the time of its release, the IBM PS/1 was widely seen as a replacement for the poorly received IBM PCjr in the consumer PC marketplace. IBM aimed the series—especially the first model, the 2011—at first-time home computer users. Accordingly, that machine shipped with PC-DOS and a handy mouse-based GUI in ROM that started instantly at boot and was available in a wide array of relatively low-cost configurations. The PS/1 line also completely ditched the Micro Channel bus of the PS/2. Later configurations upped the specs and remained fairly successful.

For home users, IBM replaced the PS/1 series with the Aptiva line in 1994. Aptiva completely melted into the background of the PC clone industry (at a time when rivals like Dell and Compaq ruled), capping a decade of groundbreaking PC machines from IBM.