TI-99/4A BASIC Performance, Games and Comparison to Other 8 Bit Systems

I heard the GPL was made so that when there's a new processor you didn't have to upgrade your code much, you could just re-use the GPL code and the GPL interpreter would make the machine language changes irrelevant. Of course, that never happened because TI got out of the home computer market. Maybe it would have been different if they were successful. Of course, they would have to allow just anyone to create a cartridge for it.

The processor was hindered by its roots - minicomputers would context switch all the time, so they made it context switch fast. A home computer is generally single tasking, so it doesn't need fast context switches. The 256 bytes of ram are hardly used at all. Would have been cool if when you read a byte it pre-loads the next X bytes on the 256, but nah... or if the built-in basic grom was not gpl. It was a neat idea, but ahead of its time, and limited by the architecture.

I loved Parsec to get the full experience you needed to have the speech synthesizer to hear the ships computer, it brought the game to a different level of experience

A friend added some cheap RAM that i bought to the expansion slot for loading some routines made with assembler to this location.

1 more retro 80s micro to speed test is the coco/dragon. It's 1 micro I don't own. The 6809 is a performer as far as 8 bits go. Good explanation on ti's reasoning with its architecture. They really missed the opportunity. Commodore/MOS had a lot to do w/ what ti settled on & released & ultimately its forced ending of its 8/16 bit platform. A footnote in the history of the PC.

16 bit

When Parsec came out, the industry was amazed by it's use of a Female Voice to make announcements via the speech synthesizer.
The Refueling Tunnel was a real challenge to navigate.

too much differences between interpreters. for example the zx80 does not have floating point variables so its performances should be the better ones. zx has floating point vars no integers ones. For a 8 bit cpu without FPU it's relatively heavy do a simple a=a+k when dealing with floating point values. Depending on the internal representation format it has to manage shifts and load/store operations on 4,5,8 bytes compared to a single or double byte load add and store operation. There are more and more others variables, such as c64 badlines or waits imposed on Z80 in the ZX Spectrum ULA etc. etc. A similar comparison is a little non sense... However, you were right, accessing the VRAM from the CPU is extremely slow. I know the TMS videochip at a good level and i can tell that a simple byte I/O from VRAM is extremely complicated thing compared to what a CPU do with its own ram, basically you do it in a lot of steps:
1) Tell the VDP the low byte of the address you want to access
2) Tell the 6 less significant bits of the high byte of address, rising or not the two significant remaining bits depending of which operation you want to achieve (memory read/memory write/register access)
3) Wait, at least some thing that could be between 3.5 to 8 microseconds (that is a lot of time for a Z80)
4) do a byte write or read

every cerimony could take a time that could be, in the worst case even 8 times longer than a simple byte store/read performed from the cpu in its own memory.

However, doing multiple reads from the same data port automatically increment the pointed address so if you want to access contiguos address in a block you can skip steps (1) and (2)

Wait, since that is a FinalGROM, you can run Extended Basic or RXBasic on it. RXBasic is significantly faster than Extended Basic even.

The TI99/4A is not an 8 bit system. It has a full 16bit bus, with 16 registers that all are 16 bits wide. The TMS9900 machine language has a multiply and divide instruction and 'feel' more like a mini computer. Unfortunately, BASIC on the TI is written in GPL (Graphics Programming Language) which is interpreted (so an interpreter in an interpreter) which makes it slow. The use of mapped video memory for BASIC program/variable storage does not make it fast either.

In ZX-Spectrum Basic variables are 5-bit float (not 4 like C64 and others) so yes, they are slowest (but more accurate)

Why does it print 500500 at the end? Is that the duration of time it took to complete?

10 CALL CLEAR
20 INPUT "What is TI-99/4A?":a$
30 IF a$ = "A big crap!" go to 50
40 goto 20
50 PRINT "Exactly!!!"

I've run this test on Commodore Plus/4 PAL version, and it completed in 50 seconds.

Hey! This was really interesting but why not run it on a CoCo or Dragon to see how it performs on a 6809 CPU?

Wow my dad had this and I remember all the games!!! I was born in 85 for context
That chomper game i remember you didn't show and the ti invaders and the car one. He had them all I think
The chomper game was jawbreaker

In a lot of basics of the era you could significantly speed up programs by explicitly DIMing variables, making sure to DIM the most frequently accessed variables before the less accessed variables.

I had a friend with a TI-99/4a back in the day and I have a recollection that you could take apart an Atari joystick and rewire it for the TI pretty easily.

I wonder how the Acorn Atom would fare in comparison.

Wonderful machine, with byte, word, and string direct access to memory, and a built in 6502 (though non standard syntax) assembler built into the BASIC..

THe assembler code could be asembled with an offset and then saved as a seperate component to be reloaded as part of another program later.

I start there I was 12

Thank You wow that was fun. I had a 99/4A way back and had the Expansion Box. Serial I/O. Pascal. and some other stuff.. I Wrote a Basic Version of Linear Programming model for a Grad School Project. And for fun I bought a Toy Robotic Arm and program some shows I saw at Disney in the GE pavilion. I enjoyed working with it. Thank You for sharing, Dennis

The memories!

This was surprising. How's come no love for the ZX-81?

Awesome Video!! Took me way back! Thank you much!

I know it's not 8-bit, but a 4-bit Sharp PC-1247 does this is 3 minutes 14 seconds.

I really enjoy Adrien's productions. He's pretty good with fixing things, even though he is quite techie with the info. You have some interesting videos yourself.

borzerk? same as berzerk for atari 2600

i have car wars or one like it for my vic 20

I enjoyed my TI99/4A system and speech synthesizer. I wrote a TI music player in BASIC, but the VRAM delays killed the pacing of the song. I later replaced my TI99/4A with Coleco ADAM for much better satisfaction.

I ran this program on the 1983 Coleco ADAM computer using Coleco SmartBASIC. While it has a TI TMS9928 VDP with 16K VRAM, it also has 64K of RAM directly accessible to the 3.58 MHz Z80 CPU. The SmartBASIC interpreter scored 24 seconds. I will have to try this same test soon with ADAM CP/M OS paired with MS BASIC for more FUN!

Extended Basic benchmarks are slower, because the cartridge does not have direct access to the buss. The memory runs through another buss, before accessing the system buss. I ran into this problem with the first computer I actually owned, an IBM PC 286, boosted to a 386 from a chip/board upgrade that fit the 286 socket. It also had an extended RAM card. So there was the system RAM on the motherboard, and then and ISA extended RAM card. Accessing the ISA card's extended RAM was considerably slower than accessing the motherboard RAM.

Perhaps the cartridge “landing strip” was a place to take notes?

Hi Noel

I’ve learned so much from your videos. Thank you

Question about the keyboard for the to-99/4a. Is it possible to map the keyboard functions to a newer style mechanical keyboard?

Loved that 9900 chip. Only 3 registers since you could use memory for the 16 programming registers. Direct mem to mem operations and 16 bit. Too bad TI made it into a brain dead machine.

Hello. About zx-spectrum basic, does the program placed in fast or slow memory? Could you repeat this test on ZX Sp+3 or Inves spectrum? Just to be sure about the slowest basic or slow down by cpu freezing, cause ULA accessed video memory the same time?

In 1982, while laid up for five months, recovering from being hit by a car (very serious injuries, and lots of them), I was given a Ti994a, and taught the basics of BASIC. I love this machine. I was thirteen. I wrote AI programs, and some useful utilities for myself. Eventually, I got EXTENDED BASIC, and developed several current-market-comparable video games, using the SPRITE commands.

While most of this video is jargon, to a degree I never wanted to attain, I watched for any nostalgia I could experience.

Parsec was awesome with the speech synthesizer option and Alpiner was even better with what sounded like digitized male and female voices.

The original Basic was slow on every machine. Lucky for Atari users, Frank Ostrowski made Turbo Basic. :D

The first time I tried one of these in a store, it looked really sleek and nicely made compared to other machines, but it also was obviously a lot slower. So I got a TRS-80 instead. It’s interesting to learn in retrospect what caused the performance issues.

The parallax scrolling on moon patrol was done in software and is awesome. Game looks great. The T.I. Invaders looks BETTER than the original, because remember the original was monochrome, with a plastic film overlay to make the different bands of color. Also, the pumping sound was very faithful to the arcade version. The TI color palate looks a LOT better than the C64. I would have loved that machine, because at the time, I was programming a TRS-80 in z-80 assembly.

Wow.. .that Amstrad CPC was a real speed demon.... relativley speaking of course....

I had the Alpiner game which was a lot of fun.

I had TI invaders and I played it so much!

I had the metal frame TI so I got more than my share of shocks from the frame.

I used to laugh for hours typing random sentences into it and pushing enter and seeing the computer's response. I often told it to 'fuck off" and it would say "Can't do that." My sister tried to download a game from a cassette tape but it didn't work. I tried to write basic programs but it was very time consuming.

Everyone else had Atari but my parents bought me this system and I loved the games.

My brother and I used to try and make programs that would run on one line of code, I believe you have to separate each statement with a semicolon. I made a program that was a simple text to speech program with the Speech Synthesizer, and my brother made a screen saver with one line of code.