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ivop

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ivop last won the day on April 9 2017

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River Patroller

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  1. Yes, very beautiful. I wondered how they did this back in the day. I guess they used some sort of a template ruler? Now I want something like this: https://www.amazon.com/Traceease-Electrical-Drafting-Designing-Measuring/dp/B08VJ9NT2Z?th=1 Looks like fun
  2. If you want people to use your library, it would really help if you had a sample application. Like a simple adventure with five locations where you have a description, can pick things up or drop them, watch your inventory, a door somewhere to open with a key that gives access to another five locations, an NPC you can talk to or give something and get something in return, et cetera. Just basic stuff. Then compile binaries for each platform you support and release a tarball/zipfile with source code which one can rebuild themselves by simple unpacking it somewhere, cd into it, and type make (assuming CC65 is installed).
  3. The LAOO palette located in RastaConverter/Palettes/laoo.act. You can tell RastaConverter which palette it should use for color matching with its /pal=Palette File command line option. I find the default atari800 palette a bit bland. You can also change its palette by setting COLOURS_PAL_EXTERNAL_PALETTE=/absolute/path/to/laoo.act in atari800.cfg.
  4. Looks like ordered dithering. Probably /dither=chess.
  5. Interesting! Sophia 2: Top and bottom left are black. Altirra 4.20: More stuff is wrong, and the small line in the lower right corner changes pixels constantly. No matter what -vert-area option I pass to atari800, it won't display more than 240 lines.
  6. If you drag the resulting image in google's reverse image search (google lens) you can easily find the original. https://images.google.com/ Then click find image source above the image.
  7. Hmm, not much really The small image can run starting as low as an Atari 400 with 16kB of RAM and a SD 810 drive. The larger image needs a drive emulator. The XL image needs 64kB (the CP/M BIOS, BDOS and CCP live under the ROM). It's especially nice to mount them from SIDE2/3 as D1:. In user area 1 there are two Atari specific programs. One to change the 40 column font (setfnt and a few example fonts) to get proper {}~ etc.. The builtin 40 column driver has blank scanlines between the mode 2 lines to avoid ascenders and descenders touching each other. There's also a loadable 80 columns driver I wrote specifically for CP/M. It uses 6x40 bytes per logical line and ANTIC to clear the line above and below, which makes line indexing very fast (one logical line per page, 16 bytes wasted). What else can you do? You can learn about the old CP/M command line and its weird syntax. REN OLDFILE=NEWFILE for example. And user areas instead of directories (and no way to copy between them, really). You can run the native 6502 assembler and assemble some of the utilities like dump and ls (asm dump.asm foo.com). There are two editors. Bedit is old style line based, qe is vi-like and runs on systems with a screen driver (which the Atari port has, both 40 and 80 columns). As said, there's Altirra Basic (not very well tested yet, but it runs). There's Conway's game of life, and a few test programs, like scrntest and vt52test after you have loaded the vt52 driver. The last one is very new and might have bugs. Edit: and of course you can study its source code I found it very interesting to see how CP/M worked back in the day and how David overcame the fixed loading address of binaries which it was known for. How relatively simple it was to get a new 8080 (and later Z80) based computer up and running with a minimal system dependent BIOS, like 3.5kB of BDOS and 2kB for a command line interpreter. The latter two being the same for every system. It's the reason why it is still used by basically anyone that creates yet another Z80-based single board computer. Write a small BIOS (less than 1kB) and your machine is up and running. Now with CP/M 65 and relocatable binaries we have more or less the same for 6502 based systems. Hence all the different ports that only differ at the BIOS level. Everything else is the same and they are binary compatible. You can run the same executable on the Atari or an Oric or any of the other supported systems.
  8. David Given is very strict about everything having a clear license, similar to https://github.com/davidgiven/cpmish . The MS BASIC situation is unclear. There are reverse engineered sources floating around the internet but strictly speaking it is still closed source and MS's IP. Unlike, for example, GW BASIC (https://devblogs.microsoft.com/commandline/microsoft-open-sources-gw-basic/ ). The good thing is that David decided to port Altirra BASIC instead which is known to us
  9. Because of licensing issues there's no MS BASIC for CP/M-65. But David ported Altirra Basic (minus the Atari specific stuff) instead.
  10. Yes, I have (author of the Atari port)
  11. I have solved it yet. Left is OUT, top is OD (clock signal based on RW, CS1 and nPhi2), right is IN. Works correctly in simulation now. Interesting to see that internally the data bus bits 4-7 are always pulled low during a read. It never occurred to me that none of the GTIA read registers use more than 4 bits.
  12. Sorry, I meant top (IN) and right side (OD). Edit: here's the part I mean (inlined a usage example):
  13. Yes. I misread the schematic and swapped to long lines. That's what you get without a hard copy. Looks like the whole rD0 (and rD1,2,3) are open drain, so no bus contention will occur. Sorry, will do that. On page 4 of the GTIA schematics, in the lower left corner there is a large triangle that is used above for reading the databus. The detailed schematic pins do not line up with when they are in use (like other details do). I assume IN as at the top of the triangle and OD is at the bottom. Is that correct?
  14. Hmm, that's not working like I hoped it would. It actually drives the line 0 when not floating instead of pulling it down. Result is bus contention.
  15. You have to create new udev rules to change the names associated with the device IDs of your two joysticks, similar to renaming network devices etc... https://ubuntuforums.org/showthread.php?t=1595666
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