Talk:IBM Personal Computer/Archive 2

Archive 1

Archive 2

This article should use SI units

I changed all of the memory units to KiB and they were reverted. However, saying that the early PC was sold with 16KB is just wrong. It wasn't. It was sold with 16KiB. Yes, the early marketing literature said it was sold with 16KB, and that's because *KiB wasn't invented when the early PC was sold.

Nevertheless, it is *wrong* to say that the machine was sold with 16KB, because it was sold with 16,384 bytes of memory, not 16,000. This is simply confusing for people reading this article today. We are not writing Wikipedia for people in 1981, we are writing it for people today. I think that the article should use proper SI units. What do others think? Simsong (talk) 05:25, 24 February 2020 (UTC)

Kibibibytes aren't particularly helpful; none of the literature at the time used "kibibytes". It's solving a problem that doesn't exist. --Wtshymanski (talk) 20:59, 26 February 2020 (UTC)

This is covered by the editing manual of style. Per WP:COMPUNITS: kibibytes should not be used in Wikipedia in this context as they are not universally recognised. None of the provided exceptions apply here. Oh: and kibibyte is not an SI unit. But then neither is kilobyte. 86.181.0.182 (talk) 13:15, 27 February 2020 (UTC)

changed to KB per WP:COMPUNITS, kB = 1000 bytes which not what is being referenced ShadyCrack (talk) 02:49, 8 June 2022 (UTC)

Requested move 3 June 2021

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: not moved. (closed by non-admin page mover) -- Calidum 20:20, 24 June 2021 (UTC)

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IBM Personal Computer → IBM PCIBM PC – IBM PC is the WP:COMMONNAME for this subject, and is more consistent with IBM PC compatible. PhotographyEdits (talk) 15:45, 2 June 2021 (UTC)

This is a contested technical request (permalink). Anthony Appleyard (talk) 09:20, 3 June 2021 (UTC)

• @PhotographyEdits and Elli: queried move request Anthony Appleyard (talk) 09:21, 3 June 2021 (UTC)
• Not clear what naming scheme we should use here - would be a pretty contentious move to do undiscussed. Should go through an RM. Elli (talk | contribs) 04:52, 3 June 2021 (UTC)
• Opppose - pointless Wiki-diddling. This is not an obscure initialism. --Wtshymanski (talk) 22:00, 8 June 2021 (UTC)
• Oppose. They are the same name anyway, and the current name sound more formal. enjoyer -- talk 22:03, 12 June 2021 (UTC)
• Comment I don't get why it is opposed. Per WP:COMMONNAME the most common name is preferred, not the name that sounds the most formal. Per WP:CRITERIA, IBM PC is recognizable, natural, precise, concise, and *more* consistent, per IBM PC compatible. IMO the page should be moved. PhotographyEdits (talk)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Printer compatibility

IBM provided two different options for connecting Centronics-compatible parallel printers. One was the IBM Printer Adapter, and the other was integrated into the MDA as the IBM Monochrome Display and Printer Adapter.

The parallel port of the original IBM PC was not Centronics compatible. It had extra interface signals that prevented printing to anything other than an IBM-badged printer, which was an Epson unit. IBM had Epson bastardize the interface for this purpose. Third-party manufacturers quickly responded by adding the necessary signals, without losing true Centronics compatibility.

216.152.18.132 (talk) 20:44, 2 September 2022 (UTC)

Storage section has some contradictions

"After the XT was released, IBM altered the design of the 5150 to add most of these capabilities, except for the upgraded power supply. At this point adding a hard drive was possible, but required the purchase of the IBM 5161 Expansion Unit, which contained a dedicated power supply and included a hard drive. Although official hard drive support did not exist, the third party market did provide early hard drives that connected to the floppy disk controller, but required a patched version of PC DOS to support the larger disk sizes."

The above passage indicates that one was "required" to buy the expansion unit to use an HDD (due to the power supply), but then states that you could use drives that connected to the floppy controller in the PC. I've personally never seen a drive inside an IBM PC that connected to the "floppy" controller, but it should be quite obvious to the reader that this wouldn't solve the PC's power supply problem. The problem is not that there was "no place to hook it up to the bus". To do this you just needed an 8 bit ISA MFM HDD card with a built in BIOS (several options at the time including one from an XT).

Additionally, the image on the page in the "hardware" section clearly shows a 5150 with a HDD installed in the system chassis (the LED is square instead of round like the FDDs have). I doubt this drive was connected to the floppy controller. Either way, it contradicts the text that proclaims it's "required" to get the expansion unit to use a hard drive.

All that said, my own personal 5150 has a stock power supply and a standard st412 hard drive installed. Works without issue. 216.164.226.167 (talk) 12:43, 13 September 2022 (UTC)

Move to SI units

The units in this article are not in Wikipedia-standard SI units. For example, the infobox says that the memory is " 16 KB – 256 KB". But that's not true. The memory was not 16,000 to 256,000 bytes. It was 16 KiB - 256 KiB. I believe that the units in this article should be correct. Simsong (talk) 23:34, 12 October 2022 (UTC)

kB = 1000 bytes, KB = 1024 bytes, so current use of KB is correct per WP:COMPUNITS ShadyCrack (talk) 03:54, 13 October 2022 (UTC)

Longer list of 5150 model numbers

Longer list of 5150 model numbers = https://www.os2museum.com/wp/ibm-pc-5150-model-numbers/ - • Sbmeirow • Talk • 12:08, 29 September 2024 (UTC)

Design process

The article states that "The IBM 801 RISC processor was also considered, since it was considerably more powerful than the other options, but rejected due to the design constraint to use off-the-shelf parts". But according to IBM 801 "The resulting CPU was operational by the summer of 1980 and was implemented using Motorola MECL-10K discrete component technology". This leads to this conclusion: IBM didn't use the 801 for its first PC because it would have heavily delayed the project not because of not being an of-the-shelf part. In fact according to IBM RT PC IBM built a PC on the 801 technology but it took another 5 years. — Preceding unsigned comment added by Klabauterfisch (talk • contribs) 21:20, 29 February 2024 (UTC)

If they had used the 801 approach the size would have been much, much larger. It wouldn't have been fit for the microcomputer market. If they had integrated the processor using VLSI technology, they would have delayed the project. And it would have been much more expensive. So there's a size, time and cost issues to not select it.

The truth being said, It wasn't very difficult to select the microprocessor as the experience with the previous project valuable to them. And they were only twelve people, so they had to act with already made things. In fact this is what lead to the DMA DRAM refresh circuit, availability.

Buran Biggest Fan (talk) 12:41, 21 November 2025 (UTC)

Code compatibility

How is the 8080 source code compatible with x86 source code?

While many mnemonics are there, many others like the instruction to load data into the registers with immediate values are not the same!

MVI A,80h Buran Biggest Fan (talk) 10:25, 21 November 2025 (UTC)