The GPL Thread

[+dhe]

A thread about Texas Instruments unique to the TI-99 home computer line Graphics Programming Language.

gpl_programmers_guide.pdf RAG_GPL_Manual.pdf

[+dhe]

I’ll start out with the first question.  I know using Monty Schmidt’s linker, it’s possible to run GPL programs from RAM.

 

Is it possible to run GPL code from the >6000 space either by running the code, or by putting GPL code in the >6000 space and pointing to it like Super Debugger puts up a menu option?

[+Lee Stewart]

8 hours ago, dhe said:

I’ll start out with the first question.  I know using Monty Schmidt’s linker, it’s possible to run GPL programs from RAM.

 

Is it possible to run GPL code from the >6000 space either by running the code, or by putting GPL code in the >6000 space and pointing to it like Super Debugger puts up a menu option?

 

Without a modified GPL interpreter (Monty Schmidt’s linker?), you are pretty much limited to GRAM space. Though you can certainly move things to/from GRAM, RAM, and VRAM in GPL, the console GPL interpreter will only branch directly to GRAM and I am fairly certain that GPL instructions are only interpreted from GRAM space.

 

...lee

[speccery]

17 hours ago, dhe said:

I’ll start out with the first question.  I know using Monty Schmidt’s linker, it’s possible to run GPL programs from RAM.

 

 

 

Is it possible to run GPL code from the >6000 space either by running the code, or by putting GPL code in the >6000 space and pointing to it like Super Debugger puts up a menu option?

 

With the grommy2 you could for example use the unused system GROM areas (>1800..>1FFF, >3800..>3FFF, >5800..>58DF) if the grommy is in GRAM mode and system GROMs copied to to GRAM.

[+TheBF]

10 hours ago, Lee Stewart said:

 

Without a modified GPL interpreter (Monty Schmidt’s linker?), you are pretty much limited to GRAM space. Though you can certainly move things to/from GRAM, RAM, and VRAM in GPL, the console GPL interpreter will only branch directly to GRAM and I am fairly certain that GPL instructions are only interpreted from GRAM space.

 

...lee

That was the thing that stopped me from trying make a GPL Forth compiler that compiled byte codes.  Shame, because it would be a pretty nice way to code GPL for weirdos like me.

[RXB]

2 hours ago, TheBF said:

That was the thing that stopped me from trying make a GPL Forth compiler that compiled byte codes.  Shame, because it would be a pretty nice way to code GPL for weirdos like me.

GPL can be run from VDP or GROM/GRAM memory. You need a interpreter to run GPL from RAM or ROM.

[+TheBF]

41 minutes ago, RXB said:

GPL can be run from VDP or GROM/GRAM memory. You need a interpreter to run GPL from RAM or ROM.

Interesting. Thanks RICH.  I will put that on the stack to start making the GPL byte-code compiler with Forthy syntax.

 

[+dhe]

2 hours ago, RXB said:

You need a interpreter to run GPL from RAM or ROM.

  Monty alternately refers to the GPLLinker as either a linker or simulator.

    Do you know what it's actually doing behind the scenes?

 

2 hours ago, RXB said:

GPL can be run from VDP or GROM/GRAM memory.

Is there an area of VDP ram you think is best to use for this purpose?

[+Lee Stewart]

6 hours ago, RXB said:

GPL can be run from VDP or GROM/GRAM memory. You need a interpreter to run GPL from RAM or ROM.

 

How does a GPL program run from VRAM?

 

...lee

[Gary from OPA]

4 hours ago, Lee Stewart said:

 

How does a GPL program run from VRAM?

 

...lee

Basically you just change r13 (>83fa) of the GPL workspace from 9800 to 8800.

Then the GPL interpreter will be reading bytes from vram instead of gram.

Just make sure you pick a spot in the 16k not being used for anything screen or stack or files wise, like at least 2000 to 3700, so you have enough room for at best one 6k grom.

[Tursi]

57 minutes ago, Gary from OPA said:

Basically you just change r13 (>83fa) of the GPL workspace from 9800 to 8800.

Then the GPL interpreter will be reading bytes from vram instead of gram.

Just make sure you pick a spot in the 16k not being used for anything screen or stack or files wise, like at least 2000 to 3700, so you have enough room for at best one 6k grom.

Is that really enough? What happens when the interpreter tries to read back the address - does it have contingencies in there for that already?

 

[+mizapf]

And the address is set differently (byte order).

[Gary from OPA]

Not going to write up everything again, let's take a trip to our time tunnel and re vist 2015 where we discuss this in depth about what can be done or not done when using vdp ram for gpl code.

 

I also in the past studied Monty linker in depth as he wrote his own 2k GPL interpreter to run cartridges out of the 32k expansion and it uses a number of hard coded jumps and sections of grom 0, I needed to work around his simulator for it SOB as some sections of code I couldn't change or move without breaking all those discs out there with cartridges converted to 32k expansion format.

 

It would be nice to rewrite Monty linker to expand it and allow usage of SAMS for running GPL code, something to add to my todo list.

 

Anyway for the vdp ram usage, see the old thread from 2015 to refresh your memory, and the limitations of running code, you can just not a full unedited program but useful for short new routines you want to do, but why if you could write it in assembly anyway, but for testing something out might get useful.

 

 

[+Lee Stewart]

The upshot of the “Internal GPL Interpreter?” thread is that you, indeed, cannot run a GPL program from VRAM, using the console GPL interpreter, without serious hacks and severe limitations. For example, the console GPL interpreter cannot directly branch to anywhere but a GRAM location—a non-starter for most programming. The fact that you can manage to get the console GPL interpreter to run some very limited GPL code from VRAM is certainly interesting but doesn’t make for a very useful program.

 

...lee

[RXB]

All know is Ryte Data GPL Assembler and Linker stated quite clearly it ran GPL from VDP

 and you had to keep a large section of VDP free for this to work.

Also as stated by Gary from OPA how it worked as you could do this with NO GRAM/GROM DEVICE USED.

 

NOTE: I do think this also ran GPL slightly slower than GRAM,

          not much slower but when using screen it was noticeable compared to GRAM.

          My thought was it was forcing loading VDP addressing unlike autoincrementing GRAM.

Edited November 5 by RXB

[RXB]

It you really want to know more I have a GPLHOW2 video with sample programs all using 

Ryte Data GPL Assembler

Ryte Data GPL Linker

 

I put this on AtariAge for a reason did everyone forget they were there?

[Gary from OPA]

2 hours ago, RXB said:

All know is Ryte Data GPL Assembler and Linker stated quite clearly it ran GPL from VDP

 and you had to keep a large section of VDP free for this to work.

Also as stated by Gary from OPA how it worked as you could do this with NO GRAM/GROM DEVICE USED.

 

NOTE: I do think this also ran GPL slightly slower than GRAM,

          not much slower but when using screen it was noticeable compared to GRAM.

          My thought was it was forcing loading VDP addressing unlike autoincrementing GRAM.

I will have to look at my old Ryte Data notes, but it can be done if you don't use the console GPL interpreter and have your own, which is not much coding around 2k like how Monty's runs GPL from 32K area, of course it will be a bit slower since now you running the interpreter from 8bit area within the 32k and not on 16bit bus.

[Tursi]

Right. But the basic point is you don't "just change r13 (>83fa) of the GPL workspace from 9800 to 8800".

 

 

[+dhe]

@tursi - there are two ways of looking at this comic. One the guy is trying to prove someone is wrong. (most common on the internet).

 

Then I look at the comic with you. I read all of your post, because in the Tursi version it goes something like this, there is more to it that just changing r13, in addition the follow conditions must be meet. Here is a short section of commented working code I wrote of the necessary steps to take, to make that work. If you have questions or need help making it work, please ask.

 

That's why we are all so thankful for you participation.

[RXB]

Ok if the Ryte Data Linker is not running from GROM how does it work with no GRAM device installed?

Not like I have not demoed this hundreds of times on Video.

[Tursi]

10 hours ago, dhe said:

@tursi - there are two ways of looking at this comic. One the guy is trying to prove someone is wrong. (most common on the internet).

 

Then I look at the comic with you. I read all of your post, because in the Tursi version it goes something like this, there is more to it that just changing r13, in addition the follow conditions must be meet. Here is a short section of commented working code I wrote of the necessary steps to take, to make that work. If you have questions or need help making it work, please ask.

 

That's why we are all so thankful for you participation.

I was thinking more about how everyone jumps on me when I'm wrong (which OF COURSE happens!!), and trying to laugh about it!

 

But thanks!!

 

[Gary from OPA]

57 minutes ago, Tursi said:

I was thinking more about how everyone jumps on me when I'm wrong (which OF COURSE happens!!), and trying to laugh about it!

 

But thanks!!

 

you are rarely wrong. -- i am just amazed how every few years some of the same questions come up. -- we need a more detailed FAQ that covers some in-depth techie hardware/software questions with detailed answers.

[+OLD CS1]

It is not uncommon for someone with skill to operate below the level of recognition or appreciation.

[RXB]

18 hours ago, OLD CS1 said:

It is not uncommon for someone with skill to operate below the level of recognition or appreciation.

Yep starting something not known about to discussions before, does not seem to get much recognition or appreciation. 

Which is odd on a thread like this on GPL and yet there is a GPL section on AtariAge not even mentioned in this thread?

Edited November 7 by RXB

[Retrospect]

Can someone make a XB to GPL compiler that spits out a Cartridge image that'll run on stock console?  

Even though we've got the fantastic xb256 and compiler , an XB to GPL compiler would still be a very nice addition to what we have.  Can it be done?  I don't care that GPL is slower.  It would still be great to have.