TI Basic Version 3.1, 4.0 and 4.1 for the TMS9900, released by TI

[kl99]

I was trying to get some infos about other Basic Releases for the 9900, and by accident found out that there are updated versions of our beloved TI Basic.

 

This is the documentation for 4.1 of TI Basic:
http://bitsavers.informatik.uni-stuttgart.de/pdf/ti/990/basic/2308769-9701A_BASIC_refMan_Dec83.pdf

 

Syntax, coding, editing, even save/run/old and their use of devices is looking almost exactly like TI Basic/ XB.

There are nice enhancements, the subroutines of most CALL statements are not included.

 

The Software was released for the TI-990 minicomputers back in 1983, those machines are running on a variant of the TMS 9900 cpu.

 

So far I found the binaries of TI Basic 3.1 Installation Disk:
ftp://www.cozx.com/pub/ti990/disks/basic_3.1.0_ins.dsk

http://www.cozx.com/~dpitts/ti990.html

Couldn't run the linux utility to extract the single files from the DS10 disk image.

 

Don't know if this Basic is double interpreting (Basic Interpreter/GPL interpreter) like our TI Basic, or if this is a GPL free TI Basic version that has the same look and feel of our Basic.

 

The question is, can this be of any use for our 99/4a or even a replacement?

[sometimes99er]

Nice.

 

Page 2-4 and -6:

 

100 INTEGER ALL

The INTEGER ALL statement assigns the integer data type to all variables in the program.

[JamesD]

That explains why TI used a BASIC that was rarely seen outside of mainframes and mini-computers.

They already had source code to it. Too bad they didn't leave it as 9900 code.

 

The first thing I'd check is the size of the executable.

If it's larger than system ROM to begin with you are out of luck for a direct replacement unless you create a banked ROM mod.

Even if it fits (as a replacement or cart) you'll need a machine with more system RAM.

Something from a mini may be set up for bank switching RAM and different addresses, so a lot of patching may be required.

I'm guessing they came up with GPL while trying to port it to use VDP RAM.

 

Then remember that the TI-99/4A has some extensions that version doesn't.

You need to tie in any 4A specific functions rewritten in 9900 code.

Once you are done, anything requiring GPL won't run on it but you could have switchable ROMs for a replacement.

For a cart you could still call existing ROMs.

 

My vote would be to try to dump the existing ROMs and put them and 16 bit RAM on a single board.

It's not impossible by any means but it could require a lot of work.

[Omega-TI]

 

The question is, can this be of any use for our 99/4a or even a replacement?

 

This is kind of interesting. I can imagine a few people might find this of use *IF* it could be put on the new 512K cart when it becomes available.

 

Compatibility with existing programs might be an issue for some. The thing is, a program written using these new commands will not compile unless the program is modified to support the new routines. One would pretty much be limited to writing only for their own entertainment.

[TheMole]

Looking at the docs this looks like it's an interpreter as well as a compiler (or maybe even some sort of JIT compiler), which is pretty cool. It also seems to be possible to save programs in object format (it even looks like that's the default). However, looking at the feature set and how it maps onto TI BASIC, I'm not sure it's worth hacking it to run on a TI. Writing a source compatible ANSI BASIC interpreter is not that hard, and will probably be a lot easier than trying to hack this into a bank-switched, VDP memory raping monster.

[JamesD]

Did you try disassembling the interpreter?

[JamesD]

*deleted*

Edited June 29, 2015 by JamesD

[JamesD]

I looked at some of the other docs and they talk about overlays which are in a disk file and something about needing 32K but that probably includes storage for your programs.
So not all of BASIC is in RAM at the same time.
This might be useful if you had a 32K RAM expansion, RAM disk or paged RAM/ROM and could turn off BASIC, but I'm guessing otherwise no.