IBM produced and sold four monitors for the original IBM PC line. Yes, 4. These monitors were the familiar IBM 5151, IBM 5153, IBM 5154, and the obscure IBM 5175. Let’s take a look at these early and iconic IBM monitors.
IBM 5151 monitor
The IBM 5151 is a 12 in monochrome monitor, and was the least expensive choice of the four, by a fairly large margin. It is likely that at one time, it was the most common of the four. Remember, in the early 1980s, color was luxury. The green screen of the IBM 5151 was perfectly adequate for running productivity software.
The 5151 CRT measured 11 and 1/2 in diagonally and had an etched screen and a long persistence to reduce glare and flicker. It caused smearing when the screen scrolled, but the long persistence and etched screen reduced eye strain, which was a big problem in the CRT era, especially because the 5151 ran at 50 hertz rather than the more common 60 hertz. Late in the CRT era it was not uncommon at all to run monitors at 75 hertz. Like most monochrome monitors, the 5151 is prone to screen burn due to the low refresh rate.
The 5151 had a resolution of 720 by 350, and used a 9 pin connector. It was compatible with IBM’s MDA adapter, but would also work with the third party Hercules card, which became its own standard due to its enhanced capabilities, such as graphics.
The 5151 did not have its own provision for power. It had a power cord that plugged into the back of the computer to get power, and it turned on when you turned on the computer.
In 1981, it was not uncommon for computer monitors to resemble small bedroom TVs, because frequently they were derived from a TV design. Some manufacturers tried to go with a modernized, streamlined look. IBM did not, going with a traditional TV look with a big gray bezel around the CRT and large knobs on the side to control brightness and contrast, just below where the tuning knobs would be on a traditional TV. The look was very conservative, but so was IBM.
The IBM 5153 was IBM’s initial color monitor. It used the CGA standard, which was digital RGB, with up to 16 colors. It had similar styling to the 5151 monitor, and used a similar looking connector, but the two were not compatible. Its .39mm dot pitch was finer than CGA really needed. It yielded a very sharp display. Third party CGA monitors often used a higher dot pitch to undercut IBM’s price.
The 5153 had a 13-in display and a resolution of 640 by 200. It was 15 and 1/2 in wide, 17 in deep, and 11 and 1/2 in tall. The 5153 was introduced in March 1983.
It was possible to plug both an MDA card and a CGA card into an IBM PC and do a dual monitor setup with both a 5151 and 5153. However, very little software used to this capability, so this is more of a curiosity than anything.
IBM 5154 (EGA)
The IBM 5154 was IBM’s EGA monitor. It had the same dimensions as the 5153, but could display 16 colors from a palette of 64 colors at a resolution of 640 by 350. This was a significant enhancement over CGA, which could only display four colors in graphics mode, and you didn’t get to choose which four of the 16 total.
IBM announced the 5154 and the associated enhanced graphics adapter in September 1984, and shipped it in January 1985. The 5154 was backwards compatible with the 5153, so you could plug it into a CGA card. However, because it was a more expensive monitor, there wasn’t much reason to do so long-term.
The 5154 was the preferred display for an IBM PC AT. While compatible with a PC or XT, the slow clock speed made for a sluggish combination with EGA. The 286 processor in an AT was a better match.
However, it was not uncommon at all to use an AT with a 5151 or 5153 to save costs.
IBM 5175 monitor and card
The little known IBM 5175 dates to 1984. It shipped with an associated graphics card that was designed for CAD applications. The 5175 could display 256 colors, out of a pallet of 4,096 from the associated graphics card. You can think of the 5175 card as in some ways the first PC GPU, with its own dedicated 8088 CPU.
The 5175 was more expensive than the computer you plugged it into, at about $5,000. However, even after buying the expensive computer, it was a bargain because it could compete with CAD workstations that cost $50,000.
That said, the card was cloned by several manufacturers, and never gained much software support. It was not very popular.
Out of the box, the 5175 monitor only worked with its dedicated graphics card, which had very limited compatibility itself. However, the 5175 could be modified to work with VGA. Surplus IBM 5175 monitors converted to VGA were available for a time through closeout dealers such as COMB and Computer Reset. Rumor is that a few remaining 5175s were discovered in Computer Reset’s warehouse in the 2019 time frame.
Early PC clones closely resembled IBM’s case design. Similarly, a number of clone monitors that closely resembled IBM’s monitor design also existed. The most popular brand name was perhaps Princeton. Princeton monitors closely resemble their IBM equivalents and frequently have better dot pitch, yielding a sharper display.
Other than the Princeton branding where IBM branding would be, it can be difficult to distinguish between a Princeton or an IBM monitor. However, where IBM monitors were painted, Princeton monitors used unpainted plastic, so a Princeton is prone to yellowing where a true blue IBM is not.
There was a time when the early IBM PC monitors were largely obsolete and you couldn’t give them away. That’s no longer the case. Retro computing has caused both those IBM CRT monitors from the first half of the 1980s and the computers they were sold with to increase in value and demand in recent years.