[Coco] Emulator

Wayne Campbell asa.rand at yahoo.com
Sun Sep 6 23:44:33 EDT 2009


On Sat, Sep 5, 2009 at 7:55 PM, TP Reitzel<tpreitzel at hotmail.com> wrote:
> We need an emulator to replace MESS.

I don't think it's that bad. I think MESS is very stable, and I find it enjoyable to use. There are just instances where the behaviour of the memory allocations are larger than the original 64K page method in the CoCo3 allowed for. While it has not been a problem, I do have to wonder if I'm exceeding the limit the original CoCo2 or 3 had in terms of available memory. If my procedures get too large, they will not run in the original environment. This defeats the purpose of creating the software to begin with. I want my programs to run on an original CoCo2 or CoCo3, whether it has 64K, 128K or 512K of RAM available. They all have the same limitation, and while I never possessed a memory board for the 1M+ sizes, I believe it applies to them as well, and that is the 64K page size limit imposed by the GIME chip.

A program written in Basic09 has a memory limit of approximately 40K. Even with separate files, the total of everything loaded into memory must not exceed 40K for both procedure size and for data requirements. I learned this writing DCom. It's bloat is my sandbox. Again, the memory allocations have not proven to be a problem, so I'm not as concerned about them.

The only improvement I could see would be in wimgtool.exe. It doesn't allow for subdirectory copying. Everything gets written to the root directory. Then I have to go into OS-9 and copy the files to the sub-directory, then delete the copies in the root directory. And this because there is no move command in NitrOS-9, though I thought there was in the original OS-9. I also have to write a modbuster procedure since there is no modbuster command in NitrOS-9.

I honestly don't remember if modbuster was an original tool, or whether it was a procedure I wrote. But I can write one. Unpack is pretty much a modbuster on a different level. Time, and testing on other CoCo systems, whether virtual or actual, will tell how well I accomplish my goal.

Wayne



      



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