111 replies to this topic

[S1500]

From my observations, it seems that most, if not all TI-99/4A websites out there on the Internet are in a state of disrepair.

Numerous TI web pages consist of dead links to other dead TI web pages. *sigh*.

99er.net seems to be in the worst shape, and yet for some reason asks for donations to their website. The file section is needlessly complicated, and broken, and the front page is just a nightmare to navigate. The video section should just stick to linking to Youtube pages(they hotlinked one of my YT vids, but that's entirely cool with me) instead of unknown-codec WMV files.

When I see webrings, I know I'm in for a site that hasn't been updated since before the Iraq war.

Oh well.

Next week we'll discuss TI-99/4A emulation being as ancient as the machine itself.

[Kurt_Woloch]

That's sad to see since the TI-99 really was an importance piece of computer history. It once was the bestselling home computer in the USA (before the VIC-20 came about), and it gave us such nice things as the sound chip that was later used in many arcade games and home systems, and the TMS9918 video chip which also found use in the Colecovision, Sega SG-1000 and MSX systems, from which the video chips of the SMS and Genesis / Mega Drive were derived and which also inspired the designers of the C-64's video chip (as they reveal somewhere on the net in an interview).

[tremoloman2006]

I agree... besides the 2600, I love the TI. I've got an extensive library but no place to discuss or ask questions about them. If any of you find a good forum please let me know.

Kurt_Woloch, on Tue Apr 10, 2007 5:12 PM, said:

That's sad to see since the TI-99 really was an importance piece of computer history. It once was the bestselling home computer in the USA (before the VIC-20 came about), and it gave us such nice things as the sound chip that was later used in many arcade games and home systems, and the TMS9918 video chip which also found use in the Colecovision, Sega SG-1000 and MSX systems, from which the video chips of the SMS and Genesis / Mega Drive were derived and which also inspired the designers of the C-64's video chip (as they reveal somewhere on the net in an interview).

[Tursi]

Rich on 99er.net seems to have very little time to work on the site. A hack attack a year or so ago destroyed the download section, and the forums have been quiet for a long time (I still check them though.) I suspect if a qualified and reliable administrator stepped up, there would be interest in making it a better site (although I have never spoke to Rich about that myself).

There are not too many sites that I spend much time at. If you can deal with paranoia, the Yahoo group at http://tech.groups.y.../group/ti99-4a/ is still relatively active (last time I checked they were still checking references at the door though ).

If you're technically minded, Theirry Nouspikel's technical pages at http://nouspikel.com/ti99 are outstanding.

A good generic site covering a few other classic machines is http://mainbyte.com/ - they have documentation, hacks, notes, pictures - very nicely done stuff.

And then there are the links at the bottom of the Wikipedia page at http://en.wikipedia.org/wiki/TI-99 - most of which are worth a look or two (and some I've duplicated here.)

[Tursi]

I'm also personally happy to help with TI99 related questions - here, or my personal forums, or at 99er.net.

[djpubba]

Kurt_Woloch, on Tue Apr 10, 2007 2:12 PM, said:

TMS9918 video chip which also found use in the Colecovision

Hold the presses... does this mean it might be possible to get component video out of a TI like we can with a Colecovision? I recently picked up a TI and googled around for a video mod but everything I came up with said "oh, you'll never get more than composite video from a TI. It comes straight out of the video chip like that."

[Tursi]

For NTSC, the 9918A outputs composite video directly. The 9928 outputs a form of component. The two chips are identical from a software point of view. If the Coleco supports component it must use the 9928.

[djpubba]

It must. I wonder if one could swap the TI's 9918A with a 9928 and use 8bitdomain's CV video mod. Oh. Oh. Oh, that would rock.

Edited by djpubba, Thu Aug 23, 2007 11:53 PM.

[Tursi]

I started researching that after reading this thread yesterday... it certainly looks possible.

I'll need to get a 9928 somehow - maybe I can find a dead Coleco somewhere. Hell, even a working one - the docs I found suggest that I should be able to do the reverse mod and still have a Coleco with composite only, but a TI with SVid

If anyone can help out with parts, let me know.

[djpubba]

It appears from further googling that UK TI 99/4a's already have a 9928 in 'em and their video connectors put out R-Y, B-Y, whatever it is.

Time to decide if swapping/modding is easier/cheaper than importing. I suppose it would depend on how much has to be done to the video signal for either one to make it spec.

[Tursi]

Quote

It appears from further googling that UK TI 99/4a's already have a 9928 in 'em and their video connectors put out R-Y, B-Y, whatever it is

I know I'm a bit late here, but they have the 9929, not 9928. It's the PAL version of the same chip, so the timings and color are different (50hz, more lines, etc). Not a huge deal if you are going to convert to RGB anyway, though. Same circuit should do either (that's why I'd like to start with a Colecovision and see how they did it ).

[djpubba]

I found a place that sells just the chip alone.

http://www.arcadechi...?products_id=85

I've got a nice desoldering iron. Let's see who get's this done first.

[almightytodd]

I find it interesting how this thread devolved from "Oh what a sad state of affairs is the TI-99/4A community" to "Cool! I'm gonna do a video mod!"

I used to have one of these computers - it may still lie hidden in a box somewhere... I remember adapting a Pascal bubble-sort routine to TI BASIC after learning about it in one of my early computer science classes - just to see if I could do it. I think I had one, maybe two game cartridges to plug into the thing, but I had no joysticks, so it wasn't a whole lot of fun to play with. I got a copy of the MESS software and set it up to run the startup screen for the TI-99/4A, but I couldn't find any software for it. I would imagine that since Texas Instruments continues to be a viable, on-going enterprise, the application of their copyrights is a bit more strict than what happened with Atari.

It was a charming little machine. It's a shame that it seems its potential was never fully realized. I think one problem with it was that to add a floppy drive to it to turn it into a "real" system was more complicated and costly than the initial purchase of the base unit. It seems to me that taking an Atari 800, Apple II or even a Radio Shack CoCo from a base unit to a full system with a floppy drive was a more viable alternative. And Atari and Apple seemed to have a lot more momentum in market share and available software. Then, of course, Commodore hit the home computer scene - first with the VIC20, and then with the C-64.

Still, look at how good this "TI Invaders" screen shot looks, compared with similar offerings from other machines at the time. It's a shame that even Bill Cosby couldn't get America to buy this machine...

[djpubba]

I had one when I was a kid. When it's your only system, you find all sorts of ways to enjoy it.

The range of quality in games for the TI was interesting. Donkey Kong for the TI was surprisingly good. Alpiner was remarkably bad. So bad, it's fun to show off to people just for a good chuckle.

I found a circuit from a Gorf arcade machine that turns R-Y, B-Y, Composite into RGB + Sync. I'm going to see if it's difficult to tweak that to work with R-Y, B-Y, Y for the '99 instead. Already sourced one from a rgvac'r and ordered the 9928 from arcadechips.com.

[Jess Ragan]

Funny you should mention that... I was thinking of doing the reverse, pulling a TMS9918 out of a junked TI99/4A and popping it into a ColecoVision with a faulty TMS9928 chip. I've looked at the schematics for both chips and wonder if I could wire a composite port directly to pin 36 on that chip.

By the way... you guys know of a reliable way to pull components from a circuit board? I'm having a hell of a time doing this, even after using a solder sucker to loosen the chips.

Edited by Jess Ragan, Sat Sep 8, 2007 2:19 AM.

[djpubba]

Use a heat gun to melt all the solder at once and pry the chip out with a screwdriver. Practice on some parts you don't care about first.

[Artlover]

djpubba, on Sat Sep 8, 2007 4:27 AM, said:

Use a heat gun to melt all the solder at once and pry the chip out with a screwdriver. Practice on some parts you don't care about first.

Good way to ruin chips & circuit boards if you ask me.

[djpubba]

You may note that he said "pulling a TMS9918 out of a junked TI99/4A" and I mentioned "Practice on some parts you don't care about first..."

A heat gun is the most efficent and easy method and is how professional parts-salvage companies do it (directed hot air flow, specifically). Practice on some parts you don't care about first to get the hang of it and you're less likely to ruin parts with a heat gun than you are with solder wick or one of those cheap radio-shack solder suckers. If you don't have access to a $300+ desoldering iron, a heat gun is a fine option.

Of course, there's always the oven, too. Bake at 500 degrees for 20 minutes and, using oven mitts, give that sucker a firm whack and ALL them parts are coming out at once. (don't really do this in a house)

[Jess Ragan]

Well, the TMS9918 is socketed, so it was no problem to remove... you just sneak a small screwdriver underneath both sides and rock it until it pops out. Unfortunately, the TMS9928 is NOT socketed, and is a complete pain in the ass to remove because it's soldered directly to the board. If I do get a heat gun (and it's likely I will), the first thing I'll do is pull the sockets out of a junked Atari 5200 board and put it on a slightly more functional ColecoVision circuit board. That way, I can swap the two chips at will, and it won't be a problem if one of them doesn't work.

[djpubba]

Jess Ragan, on Fri Sep 7, 2007 11:41 PM, said:

I've looked at the schematics for both chips and wonder if I could wire a composite port directly to pin 36 on that chip.

Oh, I just realized I forgot to reply to this part -- I'm sure you're going to need to amplify that composite signal up to line level for it to work.

We should probably consider moving this topic somewhere where people who really know what they are doing will see our foolishness and correct us.

Edited by djpubba, Sat Sep 8, 2007 1:42 PM.

[S1500]

almightytodd, on Fri Sep 7, 2007 9:55 PM, said:

I find it interesting how this thread devolved from "Oh what a sad state of affairs is the TI-99/4A community" to "Cool! I'm gonna do a video mod!"

It was a charming little machine. It's a shame that it seems its potential was never fully realized. I think one problem with it was that to add a floppy drive to it to turn it into a "real" system was more complicated and costly than the initial purchase of the base unit. It seems to me that taking an Atari 800, Apple II or even a Radio Shack CoCo from a base unit to a full system with a floppy drive was a more viable alternative. And Atari and Apple seemed to have a lot more momentum in market share and available software. Then, of course, Commodore hit the home computer scene - first with the VIC20, and then with the C-64.

You're right. There seemed to be two camps of TI-99/4A users. The casual user who may have gone no further than some games, and maybe a cassette recorder, then the hardcore user: PEB(thus disk drive) and other accessories.

I was in the latter, getting a used PEB in '86, and caling BBSes in '89 with it. Wow, to think I've been online almost 20 years now.

[Jess Ragan]

I remember that weird expansion pack... it turned the TI99/4A into an IBM XT, right? They advertised it and a bunch of other TI stuff in a catalog by Triton Technologies.

[S1500]

Jess Ragan, on Sun Sep 9, 2007 2:15 AM, said:

I remember that weird expansion pack... it turned the TI99/4A into an IBM XT, right? They advertised it and a bunch of other TI stuff in a catalog by Triton Technologies.

Yeah, I asked about it on the newsgroup. Apparently it just turned your TI into a keyboard for said XT. Seems bizarre, but quite useless.

[Tursi]

Quote

I've got a nice desoldering iron. Let's see who get's this done first.

Hehe.. I'll watch your progress with interest, but sadly I'm too far behind on other projects to take this one on just now. I've pushed it onto my mental stack.

[Brian R.]

Kurt_Woloch, on Tue Apr 10, 2007 5:12 PM, said:

That's sad to see since the TI-99 really was an importance piece of computer history. It once was the bestselling home computer in the USA (before the VIC-20 came about), and it gave us such nice things as the sound chip that was later used in many arcade games and home systems, and the TMS9918 video chip which also found use in the Colecovision, Sega SG-1000 and MSX systems, from which the video chips of the SMS and Genesis / Mega Drive were derived and which also inspired the designers of the C-64's video chip (as they reveal somewhere on the net in an interview).

I'd agree. I don't often think much of the TI, but when I do, the memories are fond.

Did anyone else see these used in schools? I remember having a computer lab at my middle school full of TIs. It wasn't until I was in high school (89 grad) that Apple was the norm.