[Coco] Emulator

[Frank Swygert]

One of the tricks I used for my genealogy database program was to use a bit of memory as a ram disk. In your case, a small ram disk could be used to store the main data files, and the various modules would all know where to quickly find it. Might have to require 512K, but anyone who uses a CoCo3 much today has that! My program was limited to the CoCo3, but in your case the main loader could test for the model then load the ram disk if a CC3 w/512K was detected. You'd have to test for CC 1/2 or 3, then test for 128/512K if CC3. I ran a little loader program that checked and called everything, also set the computer up for high speed disk operation. All data was kept on disk as you did though, but there was a trick to speeding that up also -- pre-written data files. There was a program that wrote blank data files on the disk, then the other modules simply filled in or read the files, knowing ahead of time about where the data would be. The disk had an index and the data files were numbered. The program requested data by entry file number, and knew about where it would be. If a granule on the disk later went bad there was a way to mark the data file on that granule as bad an skip it, I think. Been a while!!

Oh, the loader that speeds disk access up and I think calls a ram disk is in "Tandy's Little Wonder". I used every trick known at the time to speed the program up, and many thought it was a machine language program because of speed as well as the trick I used to make the program unlistable and appear on the disk as a m/l program. I don't recall how I did that... I think it was a trick published in Rainbow?? 

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Date: Mon, 7 Sep 2009 12:45:35 -0700 (PDT)
From: Wayne Campbell <asa.rand at yahoo.com>

I understand that. I believe that I said the GIME allows multiple pages to be available to the CPU, 1 page at a time. DCom was written in the modular fashion you speak of, and was disk-intensive. All of the data produced and used by it was contained in disk files.

What I wanted to do, but couldn't at the time, was figure out how to get different parts running in different pages and communicating between them. It would speed up the program significantly, because I could keep the data in memory instead of having to rely on disk files. The use of files slows the program down significantly.

-- 
Frank Swygert
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