UNIX99, a UNIX-like OS for the TI-99/4A (2025)

MBCook wrote: post #6

Wow. The TI-99 is such a perfect fit for this too given the chip was designed for multi-user computing in a way other home computer chips weren’t. All due to TI’s desire to use the same chip standards across all their machines big and small, IIRC.

While the CPU is a better fit than the 8 bit contemporaries, the 16kb of working memory is going to be a struggle.

Re: UNIX99, a UNIX-like OS for the TI-99/4A (2025)

#8

Post by bananamogul » Mon, Feb 23, 2026, 9:03 PM UTC

Imagine a Beowulf cluster of these.

Re: UNIX99, a UNIX-like OS for the TI-99/4A (2025)

#9

Post by SoftTalker » Mon, Feb 23, 2026, 9:11 PM UTC

@UsagiElectric on YouTube has a series of videos on building a homebrew around the TMS9900 processor. Would be cool if a unix-like OS could be used on something like that, though sounds like this project is specifically targeting the TI-99/4A system.

The TI-99/4A was the first computer I owned as a teenager. I had used TRS-80s and Apple ][ at school. I eventually bought the expansion box and a couple of accessory cards (floppy disk drive, memory and RS232). It all went in the e-waste dumpster about 20 years ago during a move.

Re: UNIX99, a UNIX-like OS for the TI-99/4A (2025)

#10

Post by MBCook » Mon, Feb 23, 2026, 9:13 PM UTC

jandrese wrote: post #7

MBCook wrote: post #6

Wow. The TI-99 is such a perfect fit for this too given the chip was designed for multi-user computing in a way other home computer chips weren’t. All due to TI’s desire to use the same chip standards across all their machines big and small, IIRC.

While the CPU is a better fit than the 8 bit contemporaries, the 16kb of working memory is going to be a struggle.

Yeah it really was an interesting choice on their part. Makes sense as a move for TI. Not the target market.