GPL on the Geneve

[pnr]

As far as I understand the Geneve had software to run GPL code and emulate a a 99/4A to a large extent.

 

Was this purely a GPL interpreter or did the Geneve include hardware emulation of GROM's?

 

[mizapf]

The GPL mode is a mode of the Gate Array on the Geneve Board which causes a rearrangement of the memory layout so that it becomes compatible to a 99/4A console. Apart from that, GPL is a loader for GK-saved cartridges and it contains the GROM contents of GROM 0-2.

 

GROMs are emulated inside the Gate Array with a selectable speed (to be precise, you can turn on additional wait states).

Edited January 28, 2016 by mizapf

[+arcadeshopper]

also you can ROMPAGE and use the original dsr's in GPL mode.. instead of the dsr routines in mdos

[+InsaneMultitasker]

To add to the thread...

 

"GPL" usually consists of 5 files.

 

The first file, GPL, is an MDOS/Geneve OS program. It sets up the environment, performs the powerups, loads an initial cartridge (optional), and does some basic housekeeping. Of most importance is that it patches the TI ROM, most notably the keyboard and joystick routines. Otherwise, the ROM and GROMs are pretty much identical to those found in a console.

 

The other four files GPM,GPN,GPO, and GPP are the TI GROMs and ROM files. GPL keeps these "pristine" so that each time you reset the TI mode, you get a fresh copy. This is important because the Geneve places the ROM in a page of RAM, which means the ROM can be corrupted more easily by a crash, and no one likes a corrupt ROM.

 

This set of program files should probably be called something other than "GPL" as it isn't an interpreter. It is a means to mimic the entire TI operating system, ROM and GROM, as closely to an original TI as possible.

[jedimatt42]

Did ever there exist any programs that ran from within the TI environment on the Geneve, that then manipulated the cartridge space, Grom or Rom? Since it is still RAM, it seems it should be possible.

 

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[+InsaneMultitasker]

Did ever there exist any programs that ran from within the TI environment on the Geneve, that then manipulated the cartridge space, Grom or Rom? Since it is still RAM, it seems it should be possible.

 

[email protected]

It was/is usually easier to write native OS programs where you can request memory pages, use system XOPs (OS calls), and take full advantage of the simpler file IO than it is to try to manipulate TI programs as you describe. That said, the Geneve provides for 'supercart' like abilities, so not only can you load GROM carts, you can run programs that require 8K RAM in the cartridge space.

 

My S&T BBS software runs from GPL mode. However, the Geneve assembly support does some internal gymnastics which allow it to use the system calls as if it were a native OS program. Manipulating GROM and ROM space is part of the equation. Heatwave BBS is proof of its successful operation.

Edited February 4, 2016 by InsaneMultitasker

[+Ksarul]

The Boot menu program did modify the GROM space. . .to change the startup screen to a customized list of programs that you could start with a single key press.

[jedimatt42]

I had the impression it was just a 'cartridge' with 'autostart' flagged in the header so the TI title screen was skipped... Did it actually modify grom space? That doesn't seem necessary for what it did.

[mizapf]

Ah yes, now that you mentioned it, I remember I removed that skipping of the TI title screen, and also translated the TI title screen to German.