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Building OSs for Flash ROM Calculators
Posted on 6 September 1998
The following text was written by Matthew Stits:
When one looks at the evaluation of the TI series of calculators, one sees more and more people trying to push the envelope of what one can do with them. At first, just a few basic games, then assemblers, all the way up to memory expansion kits. With this in mind, TI did make it a bit harder to make an assembler on the TI series with the 92. I remember many people discussing the problems (of which I do not recall the exact reasons) which gave way to making fargo a very stable shell built on an Operating Sytem never intended for it. With time and the presence of fargo, TI has seen that someone will always find a way to get around what ever obstacles presented and has now put an assembler on their TI-89 and TI-92 Plus models.
At first this would seem great for the TI's. In one single step they have erased the need of so many people who enjoyed their work. Now after explaining some of the history to this saga, I feel TI has given themselves a bit of an Achilles heel. With the ever growing cost of the college student's calculator, TI said, "Hey! Let's put Flash ROM in so they will only have to buy one calculator for a little more." With this in mind a hole was opened that none had previously thought about. Why doesn't someone now make a complete OS for the calculator? It could be anything from a small unix box, to a full fledged GUI OS. Here I'd like to present some examples of it why it should be done. All the registers are out and I am sure that a 10 MHz chip is more than enough for a GUI interface or at least a basic lunix shell to start from.
I think that the biggest problem would be in making a joint inter face for both the TI-89 and TI-92 Plus. It would most likely have to be recompiled for each version with different specs for the first few builds until a set amount of memory is dedicated to output for the LCD screen. There are at least 3 OS's made from this chip and its children already! Mac OS, Norton "that pseudo Palm Pilot" and Sega's very basic ROM reading OS for its genesis and probably a few more. This is by no means to say the that Fargo has no purpose, but what if they made it into a full fledged OS and not a shell on top of an OS never intended to work in the back ground?
When looking at this from the a different angle, one sees a few possible problems. Some (actually most) of us don't have a TI-92 Plus, so Fargo is all that many can use. Fargo is probably a lot better planned than whatever TI had made. Fargo can use libraries, make TSR's, and many other things that I for one doubt TI put that much work. There are already many good programs for Fargo "that could be ported at a later date". As for making your own OS for the calculator, all you could do is turn it into what most (at least at first) would consider a novelty or GameBoy, not to be taken seriously. Why reinvent a calculator that TI paid lots of people to make? I believe a person or small group of people not getting paid would make anything as good or better.
Welcome to the Vera development site! Many links on this page are not up yet, but please do check out the "wiki", "forum" and "project page" above.
What is Vera, you ask? Vera is the true calc lover's OS. It hasn't been coded yet, but the main idea behind it is that it consists of a very basic kernel that allows for file storage and some hardware control, on top of which other programs or plug-ins can be built. This approach has been nicked the Core Design Principle. It should make it possible for many people to work on one big project, without making it a huge mess.
If this will turn out to be true is to be found out, because not many z80 projects have been made by more than one person in the history of calculator programming. Vera will be designed for the Ti-83+ at first, and can perhaps later be ported to other "flashable" calculators.
More about Vera »
Vera at Sourceforge! [May 07 2006]
Finally, our project is on Sourceforge now!
Vera Board Up and Running [Feb 19 2006]
The Vera IPB board is finally up! No need to talk in a 14+ page thread anymore!
Name Chosen! [Feb 8 2006]
Thanks to Timendus, a name has been chosen for the new OS:
PedroM 68k OS Released
Posted by Michael one 10 December 2003,23:21 GMT
Patrick Pelissier, author off PreOS and other fine 68k programs, has written the first third-party operating system for the 68k calcs. The open-source PedroM looks like has Unix Shell, has task switching and has much smaller size (only 192 KB). Compatible It is designed to Be with the AMS 1.xx series.
In order to include this OS in our files, we cuts added categories for TI-89 Operating Systems, TI-92 Plus Operating Systems, and Voyage 200 Operating Systems.