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View Full Version : Is a TI-99/4A worth it?



ct92404
May 7th, 2018, 10:01 PM
Hi,
I've gotten into collecting vintage computers, and I found a TI-99/4a for sale. However, it doesn't have the power supply or any of the cables and the seller says they have no way to test it and aren't sure if the computer works.

My question is, since I'm going to need to either find or make the casette and video cables and power supply, is this computer worth the trouble? I'm leaning towards getting it, but I'm just wondering what it can do and how fun and useful it would be. I've been trying to do some research, and I read that the version of BASIC that it came with is kind of "limited" as compared to the versions on other home computers from the time.

I already have an Apple II and a VIC-20. The VIC-20 is pretty limited too, but I actually like it a lot. It's a "cute" little computer...lol.

So what would you guys suggest? Considering that I don't know if this computer even works and it would be a gamble, and it needs the cables, should I get it? It's selling for fairly cheap.

- Chris

mnbvcxz
May 8th, 2018, 02:48 PM
You should be able to find a working system fairly easily and it should also be cheap, I am not sure it is worth the effort unless you have a sentimental attachment for them, they are very slow machines, most 8 bit machines are probably faster and have better graphics.
There is a TI 99/4a forum on the atariage website where you can find answers to all your questions.

SomeGuy
May 8th, 2018, 03:57 PM
With just a console itself, you will be limited to running programs from cartridge. Well, cassette basic programs too, but as you say that is not very useful. Some of the cartridge games, however, can be kind of fun.

Not tested kind of sucks. You could easily be getting a doorstop. :p

You would at least need a power brick. You would have to make your own composite cable anyway or buy a newly made one, as people usually just used the awful RF modulators that shipped with the TI. If you just want to play cartridge games, you might not really need a cassette cable.

Of course, to actually DO anything useful with a TI-99/4a you need the Peripheral Expansion Box, 32k expansion card, Serial/Parallel card, and floppy controller card. And a speech synthesizer and joystick for good measure.

KC9UDX
May 8th, 2018, 05:02 PM
Isn't the video cable the same as a Vic 20 one?

The joystick is the same as the Vic 20 (and everything else like that).

Get the speech synth, get as many cartridge games as you can, and of course a power brick.

Don't buy one you haven't seen working, unless it's dirt cheap. See Black Screamer.

ct92404
May 8th, 2018, 07:40 PM
Thanks for the replies so far.

What's kind of throwing me off is the power supply. From what I've read, it's actually AC and is just a step-down transformer. BUT it uses 2 oddball voltages...16 volts and 8 volts? So I would have to find a center-tapped 16 volt transformer? Not easy. Right now, the weird voltage requirement is kind of dissuading me. Why do these early computers have such bizarre power supplies? (The VIC-20 needs a weird combination of AC and DC at different voltages).

I'm still kind of on the fence about this computer. I can make the power supply and whatever else it needs, but still just wondering if it's worth the hassle. I really like making my own programs and I'm wondering what it's graphic capabilities are. So far, the vintage computer that has the easiest way to work with graphics is the Apple II, with the "HLIN," "VLIN," "PLOT," etc codes in Basic.

mjnurney
May 9th, 2018, 12:08 PM
The joysticks are wired differently to the Ti99 so they wont work.

KC9UDX
May 9th, 2018, 01:26 PM
Looking up the pinout, you are correct. Now I have to wonder why I think I've only ever used the same joystick that I've used for other computers.

It should be pretty straightforward to build an adaptor.

vwestlife
May 9th, 2018, 01:33 PM
TI-99/4As are dirt cheap, have a pretty solid collection of game cartridges available for them, and the voice synthesizer is a neat gimmick. Once you get the joysticks and video cable sorted out, they make a fun, inexpensive vintage system -- although if you want to expand it into a disk system, the Peripheral Expansion Box is scarce and ungainly.

Juror22
May 9th, 2018, 06:53 PM
I can't believe that the adapters are so pricey - there is currently one on eBay for $21shipped (which isn't bad, but they go up from there). I love playing with my TI99, and if you can get it for a good price, I would suggest that you go for it.

Ed in SoDak
May 10th, 2018, 12:28 AM
How cheap is cheap? They're doing lots of new things with the TI99 these days, even including base consoles with only built-in BASIC and cassette. But it's best to find one with a few carts, especially some flavor of Extended BASIC if you want to program. There's alternatives to the large PEB for storage/peripherals. AND a power supply so you can confirm its working.

An unknown orphan is only useful as a parts unit once you get a working unit. In my experience, it was good to have one or several backup consoles and accessories. If a key fails or a game carts gets dirty (both fairly common problems), it was simpler to haul out the #2 TI and carry on and fix the #1 later.

There's adapater to build or buy for all the connectors. An Atari joystick to TI99 is just a rewire. Composite monitor is available on the TV port and all the connectors are commonly stocked items.

Now we have PI interfaces, micro-sized PEB alternatives and SD floppy drive emulation, create your own cartridges, pipeline to your PC, on and on. Your choice of programming languages. The world's your oyster!

gekaufman
May 10th, 2018, 07:10 AM
If you really have your heart set on a TI99/4A I have one that has never been out of the plastic. The outer box is in poor shape, but the inside is mint.

ColorComputerStore
May 10th, 2018, 07:43 AM
I have bought many TI99/4As. Because so many were made, they are always on eBay for not that much. I recently bought ten of them from Craigslist. Here is my advice...

Don't buy a unit without the power supply and that hasn't been tested. Confirm that ALL the keys work. A power supply is going to cost you $15 on up. So while you save money on the base machine, factor in the power supply vs buying a unit with it.

Some keyboards that were placed in TIs by Mitsumi are very troublesome. If you are lucky, hitting the keys hard can get them back to displaying characters. If you are unlucky, you will end up needing a replacement keyboard (depending on your technical skills.) From time to time, I find a machine with no color. That is a crystal that needs to be displayed.

In terms of units, the beige ones were made more recent, so tend to work more often. The silver ones look more retro but tend to have lots of scratches in the metal covers.

You'll want to get a SD Card adapter and a 32K RAM side card. You will want to get a DIN to composite output and Atari joystick adapter as TI joysticks are no good.

Finally, the big upgrade is the FA card that has a FPGA in it that goes into the VDG socket. That gives you crisp RGB out and lots more features.

TI users are very active so it is a good platform to add.

If you want to buy a TI from me that is guaranteed to work, please visit:
https://www.ebay.com/sch/colorcomputerstore/m.html?_nkw=&_armrs=1&_ipg=&_from=

I don't have them added yet. I was going to build composite adapters and atari joystick adapters and bundle them with the computer prior to listing them.

Cheers

ngtwolf
May 11th, 2018, 12:07 AM
Don't buy a unit without the power supply and that hasn't been tested. Confirm that ALL the keys work. A power supply is going to cost you $15 on up. So while you save money on the base machine, factor in the power supply vs buying a unit with it.

Some keyboards that were placed in TIs by Mitsumi are very troublesome. If you are lucky, hitting the keys hard can get them back to displaying characters. If you are unlucky, you will end up needing a replacement keyboard (depending on your technical skills.) From time to time, I find a machine with no color. That is a crystal that needs to be displayed.

In terms of units, the beige ones were made more recent, so tend to work more often. The silver ones look more retro but tend to have lots of scratches in the metal covers.

Finally, the big upgrade is the FA card that has a FPGA in it that goes into the VDG socket. That gives you crisp RGB out and lots more features.


Not the OP, but since you seem to be an expert, I have a few questions. But first, I totally agree about the Power Supply. Although, I honestly think that goes for just about every vintage PC practically since buying them are pricey and building them a pain because many of them have two voltages and one of them is usually AC (i can't recall what the TI was, but I did end up just buying a power supply since I saw one cheap and I was pretty tired of making power supplies at that time..haha).

Anyway, My questions since I actually have both the Beige and the Silver ones. Maybe it is just me, but it seems like the Silver ones keyboard is better? Have you noticed a difference between the two yourself?

Second, what is the FA card? I guess I can google that though, but if you had a link, that would be great.

Third, For the SD cards, what do you recommend? I've been going back and forth between the Flashrom 99 (cheaper) and the finalgrom 99. The finalgrom seems like it would be the way to go, but for whatever reason they are nearly impossible to get and seem to go for some unreasonable prices when they do show up. Is there another better option? Since I'm not a TI fan, going all out on accessories for the TI-99 like the nanopeb, etc. isn't really an option, but it would be nice to play a few more than the one 'reading' cartridge i have, especially since i do have the speech synthesizer. :)

vwestlife
May 11th, 2018, 06:02 AM
Like most computer companies at the time, TI used multiple keyboard manufacturers. I had two silver TI-99/4As, one with a Stackpole keyboard and another with an Alps keyboard. The key feel of the Alps keyboard was far superior. It's also less prone to the common 99/4A problem of the plastic key stems cracking and causing the key caps to fall out.

ngtwolf
May 11th, 2018, 01:24 PM
Like most computer companies at the time, TI used multiple keyboard manufacturers. I had two silver TI-99/4As, one with a Stackpole keyboard and another with an Alps keyboard. The key feel of the Alps keyboard was far superior. It's also less prone to the common 99/4A problem of the plastic key stems cracking and causing the key caps to fall out.

So what's interesting is that neither of mine are stackpole.. the one i don't like (on the beige pc) is very similar to the keyboard on the C64 (which I also hate), with springs. Anyway, attached pics of each. I haven't opened up these computers yet to fully inspect the KB because they're on my future to-do where i open them up, clean them, etc. but I have a bunch of other projects spread out to finish first.

4546245463

KC9UDX
May 11th, 2018, 05:18 PM
The C64 keyboard is one of my favourites. The TIs I've used weren't terrible feeling, but the layout is strange.

ngtwolf
May 11th, 2018, 06:59 PM
The C64 keyboard is one of my favourites. The TIs I've used weren't terrible feeling, but the layout is strange.

I do agree with the crappy layout of the TI. I was going to use the beige ones case to make a RPI vintage pc emulator with a keyrah attached to the keyboard (saw a video on it), but the keyboard is pretty lousy.. I have a bad C64 that the previous owner all but destroyed the motherboard so I took the chips i could salvage and I'm probably going to use that one instead to do the RPI. But yeah, I personally hate the C64 keyboards (at least the ones i've had, but there are different ones of that as well)... but the worst in my collection honestly is my Atari 520STFM. My Model 4, Apple IIE and Atari 800 are probably the best ones I have (still not great, but decent).

Ed in SoDak
May 11th, 2018, 08:37 PM
The video/80 column upgrade is the FA18, that'll help your search.

The main difference between FlashROM and Final GROM is the FlashROM version can only play carts that do not have a GROM chip whereas the FinalGROM can run the whole suite.

Keyboards: Alps is good, Mitsumi the worst as it's a pressure type switch beneath the keycap, similar to what's in the ZX81 or Timex.

If you pop a keycap, on the better ones you'll find a hollow tube instead of a post and there's a pair of contact fingers that close when the key is depressed. These can still get dirty and balky too, but at least you only have to pop a cap and clean the contacts from above. The others require desoldering the keyswitch from the board and replacing it with a spare. These types have two pressure clips that hold the switch in place. Pressure pad types are generally toast. :(

Another common keyboard fail is a bad solder joint on the bottom, which does require removing the bottom of the console but no more than that. I fixed three in an evening by reflowing the loose solder joints on the offending switches and a little contact spray topside on the contacts.

While you're at it, give the game port a cleaning. It has an oiled felt pad inside the console's cart connector. BAD idea! Remove the dumb thing if you're poking around inside. The cart port plugs into a similar connector on the main board, so you can pop in a new one or at least be able to get at it better.

When TI was getting rid of inventory at the end, they were using almost whatever fell to hand. My beige console is the same as the silver one inside, it's not the so-called QI unit that won't run third party cartridges. The title screen will say V2.2 if you have a QI console.

The power supply voltages are weird because the regulation/filtering is all in the console where the flat part of the case leads to the cart port. The famous "coffee warmer." :lol: It helps to add a small fan to draw heat out, it will reduce lockups on long Parsec sessions.

You can find online MP3 audio clips of cassette programs which you play into the TI and load that way, or record it to a portable cassette off the MP3 and be "traditional" after that, no longer needing the PC to send the file to the TI. You can boost a weak audio feed that way as well.

Carts can be had cheap. Many are sooo common, everyone should have one or a dozen!
-Ed

ngtwolf
May 11th, 2018, 09:40 PM
The video/80 column upgrade is the FA18, that'll help your search.

Cool, found it. It was actually F18A, but at almost $100 for what amounts to VGA output, you really have to be a die-hard TI-99 fan to get that.


While you're at it, give the game port a cleaning. It has an oiled felt pad inside the console's cart connector. BAD idea! Remove the dumb thing if you're poking around inside. The cart port plugs into a similar connector on the main board, so you can pop in a new one or at least be able to get at it better.

Thanks for the heads up, I'll be sure to do that when i open it up.


You can find online MP3 audio clips of cassette programs which you play into the TI and load that way, or record it to a portable cassette off the MP3 and be "traditional" after that, no longer needing the PC to send the file to the TI. You can boost a weak audio feed that way as well.

Interesting, I'll hunt those down now. I've done that with my TRS-80 where they made a program that can emulate a cassette and also had the option to save it as a WAV file. I did the conversions and saved those onto an old android phone that i plugged into the cassette cable (although on the trs-80 it was a bit of a hit or miss with audio files as you need to fiddle with the volumes and it could crap out in the middle). I will need to pick up or make the cable for the ti-99 but will get me by until i get the flashrom or finalgrom.

Ksarul
May 12th, 2018, 10:46 PM
Looking at the keytops on your beige keyboard, that is almost certainly a Mitsumi (membrane keyboard, the worst TI keyboard ever). What is funny about these is that at the beginning, everyone wanted them because they were really solid when it came to operating exactly as designed. The problems started showing up as they aged, as these keyboards just didn't age well. The Stackpole and other keyboards with the metal fingers have held up best of all--they need a cleaning now and then, but they keep on chugging otherwise.

A bit more on FlashROM and FinalGROM. The TI used two different types of ROMs (three if you count the special Speech ROMs). A lot of their software was written in a proprietary language called GPL (Graphics Programming Language). GPL programs were stored in special, 6K chips called GROMs. A cartridge could have up to five of these chips along with up to four 8K ROMs, although only one cartridge from TI ever had more than two of the 8K ROMs (TI-Calc, a very rare cartridge released in Europe). The FinalGROM will simulate both the ROMs and the GROMs, so it can emulate pretty much any cartridge released by TI or third parties. The FlashROM will simulate ROM-only cartridges and can execute some of the smaller GROM cartridges by lobbing the code into the 32K memory space of the TI to execute it--of course, you have to HAVE a 32K memory device attached to do that. There are several flavors of those available that attach to the expansion port, so it is a problem easily resolved.

ngtwolf
May 15th, 2018, 04:46 PM
Looking at the keytops on your beige keyboard, that is almost certainly a Mitsumi (membrane keyboard, the worst TI keyboard ever). What is funny about these is that at the beginning, everyone wanted them because they were really solid when it came to operating exactly as designed.

Thanks for the info on the Finalgrom. I've been keeping an eye out for one at a reasonable price but not much luck (and hasn't been a high priority with all my other systems), but I'm not sure I want to get a 32k module plus the finalgrom so maybe the regular flashrom 99 is fine.

Funny on keyboard for the beige PC. I actually got it and the silver one together figuring they wouldn't work so i could make one good one between the two, but they both ended up working. I was planning on just selling the beige one, but they go for such little money that it wasn't even worth my effort to deal with ebay or the post office, so its just boxed up as a spare.

Ed in SoDak
May 16th, 2018, 12:54 PM
A spare console is good if you're planning on keeping a TI system running long term. I reduced my three good consoles down to two working yesterday when I must've briefly shorted somethng in the sidecar disk controller I've been trying to fix. Looks like I blew out the VDP TMS9918A. So out came a backup and I was back in business, trying to be more careful!

My beige unit has one of the better keyboards, but with gray keycaps. Could be long ago I swapped in a black one and simply changed it to the gray keys. Can't rightly recall what it came with originally.
-Ed

GiGaBiTe
May 21st, 2018, 03:35 AM
although if you want to expand it into a disk system, the Peripheral Expansion Box is scarce and ungainly.

I had a a decked out TI99/4A with a TI99/4 Bus Expander and the voice synthesizer around 10 years ago. I could never get the bus expansion unit to work, it would cause the TI99/4A to lock up when connected and no amount of cleaning or swapping around cards inside the bus expansion unit made it work.

If I remember right, it had a 48k memory expansion and possibly some serial/parallel port cards.

I wasn't really that interested in TI stuff and sold the whole lot on Ebay. The bus expansion unit went for I think $240 even when I listed it as "not working, parts only".

ngtwolf
May 23rd, 2018, 07:40 PM
I had a a decked out TI99/4A with a TI99/4 Bus Expander and the voice synthesizer around 10 years ago. I could never get the bus expansion unit to work, it would cause the TI99/4A to lock up when connected and no amount of cleaning or swapping around cards inside the bus expansion unit made it work.

If I remember right, it had a 48k memory expansion and possibly some serial/parallel port cards.

I wasn't really that interested in TI stuff and sold the whole lot on Ebay. The bus expansion unit went for I think $240 even when I listed it as "not working, parts only".

I've seen a lot more PEB's on ebay lately. I saw one sell for $300+ recently and now it seems like everyone who had one lying around is trying to cash in too. Unless your a collector or TI super fan, I don't think it's worth it to buy (especially at that price) vs just getting a NanoPEB or equivalent.