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About Kchula-Rrit

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  1. Thanks, I saw that. When I wrote the batch-loader, I made two PABs, one to read the file-list (I called it a "makefile") and one for the TI LOADER routine in low RAM. I took the value at >8370, subtracted >100 and made that the data buffer for the LOADER routine, subtracted another >100 and made that the data buffer for the "makefile". I subtracted >28 (4010) and put the LOADER PAB there. Then I subtracted another >28 and put the "makefile" PAB there. I subtracted 1 and put that value into >8370 to run the batch loader. Here's the VDP memory map: It worked okay in TI994w, haven't tried on my TI yet. Hope it won't go off to the Twilight Zone. Still waiting for some parts to fix my power supply. K-R.
  2. Thanks for answering; your answer showed up as I was "re-asking". I try to use VDP RAM based on the value in >8370, rather than just using, say, >2000->2400 and hoping nothing else walks on it. When I did my batch-loader, I subtracted appropriate amounts from >8370 to allocate VDP RAM for my PABs and buffers, then updated >8370. When the loader finished, I "freed" the VDP RAM by writing the value I saved from >8370 at loader startup. I figured I could: 1. Save the value at >8370 as the "original" top-of-free-space. 2. Do the >16 subprogram. The DSR would allocate VDP RAM and update >8370. 3. This would be my "new" top-of-free-space. 4. At exit, after closing all files, I could do another >16 to re-set FILES back to the default value of 3. This leads to another question. After an assembly program is loaded into RAM, does it start-up with all files closed? Or, does the file from which the program itself loaded remain open, maybe as a link to ...? I think I just answered it; it would make sense to close the program file after loading it. K-R.
  3. Thanks for verifying that my memory isn't totally gone, as far as the BASIC/Ex-BASIC is concerned. Didn't know about how Ex-BASIC used the VDP RAM at the time; I just remembered having to do it right away. What about doing >16 Subprogram from an assembly program. Is there anything to watch for, aside from making sure all files are closed before doing the call? K-R.
  4. Are there any gotchas involved in using CALL FILES (>16) subprogram? I think an obvious one would having no files open at the time, lest the table or the files get corrupted. In 1985 I wrote a text editor in Extended BASiC and used CALL FILES (1) to free some memory. I seem to recall seeing something somewhere, back then, that CALL FILES had to be the very first statement (at least in X-BASIC), but cannot find the reference. How about in assembly? I search the forum but did not find anything. K-R.
  5. An update... I bought some 4 Amp, 2.2mH inductors and 470uF capacitors and made up a pi-filter (upper circuit in the picture below) on a breadboard. That reduced the noise on the +/- 5V lines coming out of the converter from about 400mV peak-to-peak, to about 50mV p-p. The noise did not appreciably increase when I removed the output-side capacitors to make the circuit in the bottom of the picture. Since the computer has filter/bypass caps on the boards, I'm thinking the output capacitors may be redundant anyway. Another thing I did was to accidentally let the batteries discharge to the point where they would not run the converters. The data sheet says they need a minimum of 9V to run. The power supply I used was 19V at 2.5A, and the charger was sucking all the current it could supply. It got pretty warm to the touch! More disturbing was the amount of power-supply noise that got passed through the charger to show up in the converter output. The noise dropped off quite a bit after the batteries were topped-up. I may need to put a filter on the converter input, or maybe the charger input. The proto-boards I ordered to mount the parts should arrive in the next week, so I'll find out if it really works. K-R.
  6. Great! Now I have to get an inductance meter and, probably, some more toys! K-R.
  7. Thanks for the help, but I found the problem this afternoon. When an object file failed to load, I had forgotten to close it. When I tried loading the next batch file, the routine tried to open a file that was still open. Changed the code to close the object file on failure, and everything works now. My "loader" is not really an object-file loader, like the one in the E/A cartridge. It just reads a list of object files and calls the LOADER program that the Ed/Assem startup routine puts into low RAM. I just took Tom Bentley's CLOAD batch-loader and cut it up and put it back together to be a little more robust, allow comments, force loading to low RAM, etc... So far I have it running in TI994w, until I can get my TI running again. Once I get running in my TI, I'll post it, along with the source code. K-R.
  8. Thanks for the picture. Those blue things with the stripes are inductors? I have some of those in my parts box; thought they were resistors. Boy, I have been out of touch... K-R.
  9. Thanks for the response! I'll have to make sure I do that. Since my batch-loader runs in low RAM (AORG >2680), I changed FSTLOW to end-of-my-loader so TI's loader does not over-write it. The batch loader works first time through, but bombs after resetting the symbol table. I had tried to detect if the loader is running in low RAM (AORG >2680), which may be playing havoc with the above-mentioned pointers. K-R.
  10. I was thinking of using an inductor, but figured it might ring or oscillate. I'm a major-league worry-wart. Looks like I need to get some inductors and do some experiments. Do you remember, or have a rough idea, of the inductance you used? Also, I assume that "elco" is an electrolytic capacitor. The converters I'm using are from CUT, ordered from Digi-Key. K-R.
  11. A couple of months ago I adapted my main TI to run on batteries. I used a 21V battery pack that feeds a couple of DC-DC converters. One of them puts out +12V, and the other puts out +5V, along with -5V. It seemed to work great for a bit, but the F18A video output started to change colors, so I immediately turned the power off. Haven't started it since. Before connecting the TI, I checked the converter outputs. The 5V seemed a little low, with about 150mV ripple on it. The converter data sheet suggested 100 microfarads would filter the output. Being a firm believer in over-building, I put 200 microfarads on the +5V line, but still have the ripple. My experience with these things is rather limited, so I'll have to ask the more-experienced (or at least less "rusty") than me how to flatten out this ripple. K-R.
  12. While fiddling with my K-Loader program, I thought it might be nifty to be able to reset the symbol table at the top of low RAM. For example, if I load the wrong object file by mistake, I thought it might be nice to reset the RAM free-space pointers and clear the symbol table to start over without having to reboot and reload the loader. I assume that everything between >3F38 and >3FF8 is assigned by the system when the user selects EA3 or EA5 on the Editor/Assembler menu. I was thinking that setting the eight bytes, starting at >3F30, to zeroes and then set LSTLOW to >3F38 would reset the table to the state that existed upon program start-up. When I do so, and then try to load a file, I get an "Illegal operation" (Error 3, I think). Anyone tried doing this? And succeeded? K-R.
  13. Thanks for checking, good to know that big files will load on the real thing, if nothing else. I have some new hardware to install in that computer (my Win98 machine), after which I'm going to reload everything. K-R.
  14. While trying to load object files with EA3, I found that an object file larger than 5254 (>1486) bytes will fail with "Error 3." An file of 5254 bytes will load normally. After disassembling the TI LOADER code, I did not find any indication of a file-size limitation. I found this using TI994w, most recent version. Have not tried it in a real TI, yet. K-R.
  15. Thanks for the links! More cool stuff to check out. Forgot about Mouser; they helped me with some "weird" connectors for our telescope when Digi-Key didn't have them. I'm out in "the middle of nowhere", so overnight service is pretty pricey no matter what. Martin Jones (www.mpja.com) charges a pretty penny to ship anything more than UPS ground, so I can't be in a hurry. I don't know if it is because I'm 3000 miles away, or why. Parts Express (www.parts-express.com) isn't a whole lot closer, but their shipping is much cheaper. K-R.
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