81's 99 in 17: Still a lotta love for the TI‑99/4A – TI's forgotten classic

Double interpretation overhead

The main reason that BASIC on the TI99/4a was slow was that the BASIC interpreter was not written in assembly language (which would not have been difficult, as the TMS9900 was much easier to program than 8-bit alternatives such as 6502 or Z80), but in a language called GPL (Graphics Programming Language), which was compiled to a byte code that was interpreted by the CPU. I estimate the overhead of using interpreted byte code to be 5-10 times, so a BASIC interpreter written directly in assembly language would have sped up the BASIC enormously -- depending on what you do, though. For some operations such as floating-point calculation or graphics primitives, the overhead is relatively small, but for integer calculations it is pretty hefty. Games that are written in assembly language are not affected by this, but I still find it a curious design decision -- it made the TI99/4a compare very badly to other home computers in BASIC benchmarks, which is what most magazines used to compare speed of home computers.

What no Geneve?

Slightly surprised there was no mention of the Geneve 9640, a 3rd-party replacement motherboard that could be installed in the Peripheral Expansion Box to make it into a stand-alone computer. It delivered most of the improvements of the stillborn TI 99/8 and more, realising the potential of the TI.

It was a very impressive upgrade and shows what TI could have done with the machine if it had stuck with it.

http://www.mainbyte.com/ti99/geneve/geneve.html

http://www.old-computers.com/museum/computer.asp?c=1208&st=1

TI 9900 SBP

Those of us who worked at TI North in those years used TI 9900 computers in an automated test environment. Some of the Airborne Radar Systems used TI 9900 processors. Look up the MRCA Tornado. TI was first to 16 bit architecture, but TI was a closed development culture and did not understand the advantage of open architecture.

Never did it for me

I go misty eyed at most bit of kit but even in the day I never got the TI99/4a. How could somethin which was 16bit be so much slower than the 8bit computers?

Then of course we got the QL (albeit with an 8bit bus) and found out.

Was it really so short lived?

I was convinced this machine remained a fixture throughout the 1980s - it seemed to be in every Argos catalogue for year after year after year...

The first computer I owned...

I had the occasional brush with an Apple IIe before (where I learned some very, well, basic BASIC), when Sears liquidated their stocks in ~83 or 84, my parents bought it for me.

Soon enough, I had scrounged the extra peripherals - the speech synthesizer, the external expansion (with slotted RAM on an external bus AND a floppy) and, the grand prize of them all, an ASSEMBLER cartridge that basically gave you access to assembly coding.

So there I was at ~12 years old, having only a few months of self-training in BASIC, learning assembly on the TI-99/4A with zero resources other than a 4-inches thick manual in english (which I needed a french-english paper dictionnary at the time to understand).

Good times!

That's what got me started anyway, so I still have great memories of this little computer.

Tried to compete with...

The Radio Shack Color Computer ("CoCo") and really didn't do a reasonable job.

The CoCo had a reasonable version of Basic when powered on, and could be purchased with a reasonable amount of memory (16k was available) off the shelf. It had a bunch of cartridges thad actually DID things you wanted to do (you could even get a spreadsheet one), and the whole thing was priced pretty reasonably. The CoCo even went through a couple of upgrades along the way. If you were really adventurous you could get OS-9 (cut down Unix "-ish") to work with floppy disks.

Me? I bought a 4k model that lasted at 4k for about 1 hour after I opened up the box. I upgraded it to 32k before the day was done. Somewhere I still have the box buried somewhere, and it is at 64k bytes. The 6809 processor was a pretty good 8 bit CPU (probably the best overall!).

Fun times.

Loved this machine

I wrote a couple of books for this machine back in the days, "Making The Most of your TI-99/4A" and "Dynamic Games for your TI-99/4A". I've still got a box full of 'em in my loft courtesy of the publishers. Not much demand for them these days!

I remember it

I remember it being crap.

Similar things are done on CPCs

Over at CPCWiki there's the same kind of stuff going on; 'jukebox' carts for the short lived GX4000 gaming system (and the CPC+ models), the ubiquitous HXc floppy emulators and others including IDE HDDs, alternative ROMs, 4MB expansions, etc. And of course loads of new software

I was amazed when I had a Poke about....

The TI9900

If I remember correctly this was a novel processor design that was RISC-like in implementation and well ahead of the curve in that respect. Also it used blocks of main memory as the register set which allowed for rapid context switching. So there were clever guys working in an American company and the rest is history.

Parts at Radio Shack

When TI discontinued the TI-99/4A they must have had a LOT of parts left over. It seemed like for years Radio Shack had TI-99/4A bits for sale. I must have bought a half dozen or so of the power supply boards, I think they were something like $5, and they were nice power supplies.

Mate of mine had a TI99/4a, remember there was a decent port of 'Defender' that kept us quite amused. I kind of miss those days, I had an Acorn Electron, other school chums had different machines, BBC model 'B', Commodore 64, Dragon 32, Amstrad CPC, Spectrums in various guises, we went around each other's houses to discover what each machine could do. And before you ask, yes, we played D&D, and no, I wasn't the chubby one.

Bah TI wasn't any good

There was one TI-99 in high school, but it wasn't worth the time. Too underpowered, too lame. The physics dept had it, but I never saw anybody doing anything in earnest on it.

The business education dept. had an entire lab of Commodore Pets !

(We made the very first malware there - by rapidly POKEing the video adapter into different modes, we got the video chip to overheat - we ran this on every PET in the lab over lunch break, afterwards the lab teacher came back to a room full of smoke and pricey machines seemingly destroyed - off/on and back to work with yew! No lasting damage, that's how good Commodore equipt. was back in the day.)

The *real* retro machine was the Vectrex. I actually got one, years & years after they had been discontinued, and bought the combo cart (with every single game ever released on one menu-accessible cart).

A few years later I was like "man what's up with this old junk" and pitched it.

Moving on ....

Happy memories

I too had one. I remember the graphics being quite advanced at the time, the BASIC had sprite capability I believe.

Me and a mate wrote a Connect 4 game for it and had it published in a Computer mag, I remember getting a letter back from Robert Schifreen who was working there at the time. He went on to "other projects" :D and gained some notoriety!

First computer, right here

Wow, yep, this was the first machine I ever had. My old man worked retail and brought a (discontinued) one home for three-year-old me. He soon connected me with a workmate of his who'd gone fully-loaded-peripheral-box-crazy over these things, and who promptly drowned me in software and know-how. The Speech Synthesizer was especially fun - I remember being able to feed it phonetically-spelled text that sounded pretty natural - especially for the mid-80's.

I still love the robotic-chicken noise of the tape recorder reading in a tape of, say, Tunnels of Doom. Sounds like home.

99/4A Sprites!

I had a 99/4A as my 2nd or 3rd computer (I don't remember if I had it right before or after the OSI C1P but it was after the Netronics 1802 Elf). I totally loved the advanced graphics ability it had, using sprites as independent objects. But the cost of the expansion chassis and modules prevented me from hanging on to it for very long. For years afterward I used other peoples mainframes via Hazeltine 1420 or LSI Adm3A terminals until I managed to get a Mac IIx with A/UX

Still Got Mine!

I have a beige Ti99/4a and it still runs great. Just wish I hadn't left my data cassette in the cassette player, and then stored in the attic for 20 years. It snapped, trying to read.

I'd coded a flat file Traveller ship database on there, with vector drawn deck plans, as well as a D&D character generator and of course, a dice roller. I also had a 4 channel conversion of Steven Howe's Mood For A Day. No, not a nerd, not nerdy at ALL!

The machines look cool. All the games are pretty shite and nothing an emulator won't help with.