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The IBM 5153 Personal Computer Color Display was a monitor designed to accompany the original IBM PC (albeit released a couple of years later) and provide a color display at sharp enough resolution to be usable with 80 columns of text.

Of course in principle you could use a color TV, but the fine detail was blurry and marred by NTSC color artifacts, so that it was problematic trying to work with much more than 40 columns on such a setup.

The reasons for the difference at the electronic level are clear: Some picture clarity is lost in the RF encoding phase, more in the encoding of color in the chroma signal that was necessary for backward compatibility with black and white TV sets. But what were the differences in the actual picture tube?

If you took all the electronics from a monitor like the IBM 5153 and substituted just the picture tube from a color TV, what would still be lacking in terms of display quality?

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    At the electronic circuit level, this doesn't really make sense as a question IMO. It's a bit like asking "if you replaced the dashboard of a Ford car with one made by Chrysler, would the instruments work?" Of course you could make them work by changing enough other things as well, but that doesn't seem to be the point of asking the question. – alephzero Apr 5 at 16:58
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    @alephzero Similarly here, my point is that I know about things like the chroma signal, that have been extensively discussed before, but what about the actual picture tube? And I'm hoping for an answer that talks about things like the phosphors and grid mask. – rwallace Apr 5 at 17:07
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    @rwallace I expect that the 5153 would have a triad shadow mask where a TV has an in-line shadow mask. It will be interesting to hear if the phosphor or anything else about the CRT is any different. – snips-n-snails Apr 5 at 17:18
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    Here's the reference guide for the 5153: minuszerodegrees.net/oa/… – snips-n-snails Apr 5 at 17:20
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    Well, we have a part number for the original tube 370RKB22-TC14 from @traal's reference, but nothing much more than that on the Web, it seems. I was taking the OP's question a bit more literally: if you just connect the 5153 output that drives the tube to a "colour TV tube" with different deflection sensitivity, different HT and intensity modulation and focus voltages, and different heater supplies, you will most likely get either nothing or a complete mess (and in the worst case, a loud bang and a lot of magic smoke). – alephzero Apr 5 at 19:17
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The question doesn't make much sense.

CGA works within TV spec of a standard line rate close to 16 kHz. Thus any CRT fitting must be capable to operate at ~16 kHz. Which is what each and every TV tube does. The mask of any colour CRT at this time was way better than needed for 640 pixel (80 columns with 8 pixel each). As a result next to any colour CRT can be used.

There is no commercial sense in making a special CRT for a few thousand IBM displays when standard TV CRT where already produced by the million.

Te real difference is how the data (signals) are presented to, and turned into beam motion, by the display electronics. When it reaches the tube it's all the same.

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    I strongly suspect that "The mask of any colour CRT at this time was way better than needed for 640 pixel (80 columns with 8 pixel each). As a result next to any colour CRT can be used." is exactly the answer that was being sought. – Tommy Apr 5 at 20:43
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    @Tommy It is indeed! Custom is to wait a day before accepting an answer, but that's exactly what I was curious about. – rwallace Apr 5 at 22:35
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    I believe TVs used a slot mask to optimize brightness while monitors used a dot mask to optimize resolution/clarity. – snips-n-snails Apr 5 at 23:54
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    @traal You're right, different mask designs are optimizations toward different goals (as always in in real life), but at the level we're talking it isn't as big as it may seam. Then again, the dot (or shadow) mask is the default for TV. It wasn't until 1980 that Sony Triniton became a mainstream success with their slit masks. Slot (or EDP) mask is a development of Hitachi of 1987 (way after the 5153) combining both ideas - large elliptical slots grouped as a triangle. So when looking at the 5153 time frame, it's dot masks either way (unless they where Sony - which they were not). – Raffzahn Apr 6 at 0:24
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    "The mask of any colour CRT at this time was way better than needed for 640 pixel (80 columns with 8 pixel each)" - er, no. repairfaq.cis.upenn.edu/sam/crtfaq.htm#crtdpt vcfed.org/forum/showthread.php?14701-Pre-VGA-Monitor-dot-pitch – Bruce Abbott Apr 6 at 1:00

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