Getting Color Output out of a TI-99/4A • Hacker News Board

Re: Getting Color Output out of a TI-99/4A

#21

Post by blazor » Sun, Sep 06, 2020, 2:45 AM UTC

the TI99/4A is a beautiful machine.

The first computer I ever used back in 1982 was Texas Instruments 990/10 minicomputer (384K) running an operating system called DX10, based on the same instruction set as the 99/4A.

That system was originally built for a US Motel operator reservation system. Back in the days when you would quote for developing not only the software but the hardware too!

Today if you are interested you can download a 990 emulator and experiment with DX10/DNOS for yourself

Re: Getting Color Output out of a TI-99/4A

#22

Post by lebuffon » Sun, Sep 06, 2020, 2:57 AM UTC

13of40 wrote: post #16

bitwize wrote: post #5

Props to you. The TI-99/4A was my second -- and longest childhood -- computer. Getting one working again so perfectly warms my heart. Fun fact about the TI-99/4A: It was actually fast , sporting a 16-bit CPU in an 8-bit era. The BASIC interpreter was slow because it, like many TI-99/4A programs, was written in a sort of interpreted bytecode that could live in video RAM/ROM. The CPU itself had access to only 256 bytes…

You sound like you know a bit about TI-99s, so let me ask you this: Do you have any idea why they made the lower case character set be small upper case letters instead of real lowercase like the Apple II or C64? A couple of years ago I did a Sunday morning project of inserting the Apple II font into the TI-99 ROM to run on an emulator, and other than having to shift the j's and g's up a pixel or two it worked beautif…

The TI-99/4 was Uppercase only. I think the lower case font for /4A was a rush job but I don't know that for certain. For the hobbyist playing with the machine today there are many 10s of different fonts that have been developed and it doesn't take much to load them in BASIC, Forth, C or Assembler.

Re: Getting Color Output out of a TI-99/4A

#23

Post by wsc981 » Sun, Sep 06, 2020, 3:11 AM UTC

incanus77 wrote: post #3

Not to denigrate the post, but the TI-99/4A did color out of the box; this post is talking about a modern adapter board to work with a modern display instead of TI's proprietary monitor or a TV. I know because I first programmed on a TI-99/4A and we didn't have the space nor free connection to hook it to the living room TV, so I used a 13" B&W TV in my room for years before ever seeing the color that it was capable o…

My father owned a TI-99/4A and used it to teach me some programming. Afterwards I mostly just copied listings from the TI-jdingen magazine (published by the Dutch TI users group TIGG [0]). Together with my dad I also made a small game. Nothing to impressive. Basically just a ship that automatically moved from the left to the right side of the screen. The player could press a button to shoot a projectile on randomly generated airplanes that would fly from right to left.

I know Edsger Dijkstra considered the BASIC language to cause brain damage [1], but still at times I feel like it would be nice to program in a language like TI-BASIC again, just modernised a bit.

---

[0]: http://www.ti-99.nl

[1]: https://programmingisterrible.com/post/40132515169/dijkstra-...

Re: Getting Color Output out of a TI-99/4A

#24

Post by at_a_remove » Sun, Sep 06, 2020, 4:09 AM UTC

I had such great times with mine, aside from the games.

I remember the first game I programmed on it, sort of a cross between Pac-Man and Berzerk, so walls and pits and various things chasing you. Due to the doubly-interpreted BASIC, it was quite slow and I was vexed; checking motion into walls and pits got more and more slow with each obstacle. Eventually I hit on, rather than a series of IF statements defining a wall that one might not move onto, I could simply draw my walls and pits, then check the video array directly! Suddenly, my game was so much faster.

It was the first time I had an optimization that relied on knowing something about the hardware.

Re: Getting Color Output out of a TI-99/4A

#25

Post by SpikedCola » Sun, Sep 06, 2020, 4:23 AM UTC

I really enjoy the little mod PCB "TMS-RGB"[0] that makes this possible. Takes me back to my modchip days. I'd like to find a project that needs one of these designed - always wanted to make one myself but never had a reason.

[0] https://github.com/npiegdon/tms-rgb

Re: Getting Color Output out of a TI-99/4A

#26

Post by incanus77 » Sun, Sep 06, 2020, 5:31 AM UTC

wsc981 wrote: post #23

incanus77 wrote: post #3

Not to denigrate the post, but the TI-99/4A did color out of the box; this post is talking about a modern adapter board to work with a modern display instead of TI's proprietary monitor or a TV. I know because I first programmed on a TI-99/4A and we didn't have the space nor free connection to hook it to the living room TV, so I used a 13" B&W TV in my room for years before ever seeing the color that it was capable o…

My father owned a TI-99/4A and used it to teach me some programming. Afterwards I mostly just copied listings from the TI-jdingen magazine (published by the Dutch TI users group TIGG [0]). Together with my dad I also made a small game. Nothing to impressive. Basically just a ship that automatically moved from the left to the right side of the screen. The player could press a button to shoot a projectile on randomly g…

What sorts of modernizations would you like to see? Things removed (GOTO) or things added?

Re: Getting Color Output out of a TI-99/4A

#27

Post by Zardoz84 » Sun, Sep 06, 2020, 8:05 AM UTC

gbin wrote: post #11

I am confused, just get a scart cable and a scart to hdmi. Done. Scart supports a bunch of TV image formats (composite, svideo, rgb etc..). In All the TIs, Amiga, Amstrad, etc... Work ootb. You can find those converters for a few bucks on ebay. If you want to get fancy buy yourself an OSSC to get a really good image quality.

this wouldn't work fine with a Amiga. It supports some video modes that can be displayed on a TV. So needs a Commodore monitor or a scan doublet.

Also, the video output of some computers barely get in the standard. Yes, an analog TV can handle it fine, but try again on digital. I have a composite/SCART to VGA and can't sync correctly the composite output of my Spectrum +2. However, the same output it's handled correctly on my Commodore monitor

Re: Getting Color Output out of a TI-99/4A

#28

Post by blazor » Sun, Sep 06, 2020, 8:10 AM UTC

13of40 wrote: post #16

bitwize wrote: post #5

Props to you. The TI-99/4A was my second -- and longest childhood -- computer. Getting one working again so perfectly warms my heart. Fun fact about the TI-99/4A: It was actually fast , sporting a 16-bit CPU in an 8-bit era. The BASIC interpreter was slow because it, like many TI-99/4A programs, was written in a sort of interpreted bytecode that could live in video RAM/ROM. The CPU itself had access to only 256 bytes…

You sound like you know a bit about TI-99s, so let me ask you this: Do you have any idea why they made the lower case character set be small upper case letters instead of real lowercase like the Apple II or C64? A couple of years ago I did a Sunday morning project of inserting the Apple II font into the TI-99 ROM to run on an emulator, and other than having to shift the j's and g's up a pixel or two it worked beautif…

The TI 990/10 DX 10 minicomputer was exactly the same. The teacher at my old school actually picked the TI990/10 over the PDP/11 because the PDP11 did not have "true descenders". The 990 didn't either but avoided the problem by having miniature capitals for lowercase.

He was a strange guy. Long since departed.

Re: Getting Color Output out of a TI-99/4A

#29

Post by blazor » Sun, Sep 06, 2020, 8:12 AM UTC

blazor wrote: post #28

13of40 wrote: post #16

Earlier quoted context omitted.

You sound like you know a bit about TI-99s, so let me ask you this: Do you have any idea why they made the lower case character set be small upper case letters instead of real lowercase like the Apple II or C64? A couple of years ago I did a Sunday morning project of inserting the Apple II font into the TI-99 ROM to run on an emulator, and other than having to shift the j's and g's up a pixel or two it worked beautif…

The TI 990/10 DX 10 minicomputer was exactly the same. The teacher at my old school actually picked the TI990/10 over the PDP/11 because the PDP11 did not have "true descenders". The 990 didn't either but avoided the problem by having miniature capitals for lowercase. He was a strange guy. Long since departed.

additional: His name was Billy Boyd. And he pronounced it: "TWOO descenders"

Re: Getting Color Output out of a TI-99/4A

#30

Post by musiccog » Sun, Sep 06, 2020, 8:12 AM UTC

In my last year of primary school a teacher brought in a mate he had to give the class a lesson on computers for an hour or two. He brought in a TI99 and we spent the afternoon learning about programming, graphics and 'sprites'(yes he had the expansion)

..after the lesson, I went up to him (Graeme) and asked if he would tutor me after school.

I then spent the rest of the year - (two afternoons a week) learning programming - and have been doing it ever since.

Graeme wasn't what I would call a great teacher - but he gave me the opportunity.

I remember my first program was a copy of a game called something like 'Wild Gunmen' where one or two players tried to get into a situation to shoot each other.

I eventually got a TI99/4a a few years later (as it was selling for $99(AUD). Wrote a flight simulator (dials only) and something that I really loved - an almost perfect copy of Frogger including music! The most annoying problem with the TI99/4a (apart from loading from tape) was that it hated running out of memory - and when it did would just crash. That always meant a reload from tape, optimize something, save to tape, and try again. Lots of fun.