Talk:IBM Personal Computer

Mion's plan is anachronistic

The History section says, In the summer of 1979...Mion recommended Digital Research’s CP/M and a new O/S called MS-DOS from a little-known company named Microsoft. But the DOS itself, Seattle Computer Products 86-DOS, was not released until 1980, and Microsoft didn't buy it and rename it MS-DOS until 1981. Cjs (talk) 15:02, 18 April 2025 (UTC)

This first version was shipped in August 1980. Microsoft, which needed an operating system for the IBM Personal Computer, hired Tim Paterson in May 1981 and bought 86-DOS 1.10 for US$25,000 that July. Microsoft kept the version number, but renamed it MS-DOS. They also licensed MS-DOS 1.10/1.14 to IBM, which, in August 1981, offered it as PC DOS 1.0 as one of three operating systems for the IBM 5150 or the IBM PC https://en.wikipedia.org/wiki/MS-DOS ~2026-40553-42 (talk) 21:49, 19 July 2026 (UTC)

Keyboard similarity between the PC and the Datamaster

The keyboard design of the original IBM PC does not resemble the one from the Datamaster other than the usage of a 8048 as main element. One of the reasons is that they employed an 8-bit matrix in the Datamaster while using a 4-bit one in the 5150. However, even if it seems strange, they recovered the architecture with a serial interface and a different matrix with the F/XT type 2.

Buran Biggest Fan (talk) 10:31, 21 November 2025 (UTC)

IBM PC and Microsoft BASIC

The main reason of the selection of the Microsoft BASIC was not due to people being more used to Microsoft BASIC (which already had lots of dialects). It has more to do with timings than anything else because the BASIC employed in its precursor, the Datamaster, delayed the project more than a year and they did not want to commit the same mistake by having to port it again.

Buran Biggest Fan (talk) 10:35, 21 November 2025 (UTC)

IBM PCPG

There was a proposal on Talk:IBM PCPG to merge this, by Y-71-JimmG, a couple of years ago. Let's do it. Bearian (talk) 09:08, 9 February 2026 (UTC)

No. Someone's obscure non-notable pet project has no relevance to this article. --Wtshymanski (talk) 19:46, 10 February 2026 (UTC)

Ok. Bearian (talk) 13:43, 28 February 2026 (UTC)

Design process (2)

I wouldn't consider the Bill Gates interview as a valid source for the design stage of the PC. Microsoft did not design the PC and was not involved at all in the creation of the hardware. Therefore, he can't know anything first-hand.

It's sad, because I can't publish unpublished content, but I talked with some people involved in the creation in the PC when I was researching for the Datamaster oral history. The reasons for the selection of the CPU were the following:

• It had to be an off-the-shelf part
• Had to have an internal 16-bit architecture
• It had to work with the MCS-85 peripheral components the developers were already used to
• The resulting system had to inherit the Datamaster expansion bus without having to modify it heavily
• It had to be as cheap as possible

Being off-the-shelf immediately discards the 801 option.

Being at least 16 bits discards the 6502, the Z80 and other 8-bit CPUs.

The MCS-85 requirement discards CPUs employing the Motorola / 6502 bus.

The Datamaster expansion bus has an 8-bit data bus and an address latch enable for multiplexed address/data pins.

With the previous and the need to make a reduced cost launch memory had to be drastically reduced in the most economical configuration. Since the dynamic memories employed both in the Datamaster and the PC are 16K x 1, if they had employed a 16-bit data bus the minimum amount of memory they would have needed would have been 32K x 8 plus two extra 16K memories for parity check.

So... if they couldn't use the 801 processor, no 8-bit CPUs, had to have an Intel bus with ALE compatibility and 8-bit data bus, what else remains that was marketed in 1980? Only the 8088. Buran Biggest Fan (talk) 21:58, 12 August 2026 (UTC)