Re: Random Sam BASIC question.
Sorry, I was very busy improving my Retro-X in the last time. I found more and more messages from Sam-users in my gmail spam directory... Thomas Harte schrieb: Aha. I never stop learning. That was completly new for me... For Acorn emulation I currently use Beeb. Just requested from the authors to have a binary PC file import and export-function for one of the next versions, like Sim Coupé. I have never heard about your emulator. Is there a Acorn Electron screen interpreter/viewer available? I should test the export of my screen converter, how it works on a emulator, but without binary import it is a bit hard. Oh, my emulator is ElectrEm, at http://electrem.acornelectron.co.uk, though it doesn't import or export binary files at present. That's probably a more startling revelation if I also reveal that it does import and export ASCII text format BASIC programs. I've been doing some work to it in the last few days anyway, to improve printer emulation (I catch and interpret Epson FX80 typographic codes but so far haven't been doing graphics) and to fix up some bugs that have crept in while I was adding various other improvements, so I'll look into that. Even if it does not import binary files, your link helped me to get some important documents about Acorn. Now my Retro-X is also able to convert images to all Acorn graphical modes (0,1,2,4,5). I requested the binary import/export feature for Beeb Emulator and the latest release got these features now. Your Tokeniser is a great idea... In the meantime, I can provide a little assembly sourcefile compatible with BeebAsm (roughly analogous to JAM or pyz80 in that it assembles code directly to an emulator-friendly media image — see http://www.retrosoftware.co.uk/wiki/index.php/BeebAsm) that will use the contents of a binary file to assemble such that when you run the resulting DFS it just puts the contents on screen. So you'd just have to put the binary output of RetroX with the asm, run the assembler, then launch the emulator to test. This would be a nice feature if I can build it into my program, to generate fully executable files, eventually wuith compressor. At moment I do not know the TAP format of Acorn and also no details about disc image formats, but because there is much to do with other stuff, this is something for future. Anyway I'm happy that Beeb's import works fine. I generate my files and can import them in debugger with fr 3000 command (xxx=filename, 3000 replaced by 5800 in modes with 10240 bytes screen size) I'm clueless about the BBC hardware (apart from the CPU, the Electron shares nothing with the BBC on a component level), but hopefully there's a BBC emulator that does the binary loading/saving you want. Now yes! BTW. Do you use API calls in your emulator? I'm looking for a reference of Linux and Mac API calls online. There are a lot of Windows API calls documented, but no Linux and Mac calls. I looking for example for the eqivalent of GetAsyncKeyState(). There is a demand for Retro-X on Mac and Linux... I think SDL itself might still be using some of the libraries that OS X inherited from all the OSs before it, which are all deprecated now and generally not a good idea. http://developer.apple.com/documentation/Cocoa/ is probably the best reference resource, but I wouldn't describe myself as an unadulterated fan. Cocoa looks like it would be a nice library, but because I do not use C or C++ but PureBasic, so I should write a wrapper first. Anyway this is a good starting point for the conversion to other OSes. Thats right... I also use ithe Internet to do some research about graphics formats and image preprocessing. Asking people to help, helping other people... In the 80 my programs are just simple and small games, and Utilitys, in the 90 I learned to code better games and used first time my own graphics converter that I wrote on Amiga. And now with PC I'm stick to internet having not much free time to finish coding my projects. I don't know if I even had a computer in the 80s... I think probably not. I was only born in 1980, so I guess my parents wanted me running around outside instead, which I did and seem to remember very much enjoying. I had a secondhand Electron for about a year before my Sam, then skipped the 16 bits entirely to go PC and then Mac. The internet, which I think we first got a link to in 1996 or 1997, was a revelation. I was born in 1971, so my Home computer experience begann 1985 with a Spectrum 48+, then I moved to Spectrum 128, In late 80's I had a Amiga 500, then I moved again to Spectrum and 1990 I purchased my SAM Coupé, then 1995 my first PC. I do never like to play outside, so I prefered to play with my computers. I think, I got Internet in 1998. I think the only thing of any length I ever wrote on my real Sam was an Outwrite clone in BASIC. It was very slow indeed, and couldn't print. That sounds cool! I wrote some SAM games like
Re: Random Sam BASIC question.
I meant are they read/write, or write only? However in the interim, I've found a copy of the Technical Manual online and discovered that they are read/write, which I wasn't expecting. On 28 Aug 2008, at 21:06, Leszek Chmielewski wrote: 251 = High Memory Page Register 250= Low Memory Page Register Greetings, LCD Thomas Harte schrieb: Port 252 is read/write? Anybody got any idea about ports 250 251? On 28 Aug 2008, at 20:22, Leszek Chmielewski wrote: James R Curry schrieb: Okay, utterly random question... How does one determine the start address of the screen in Sam BASIC? I forget. It has been years. -- James R Curry [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] SAM adv. technical manual says: 10 LET A=IN 252 BAND 31 20 LET BASE=(A+1)*16384 BASE=Start of Screen greetings LCD P.S. But the structure of Information in Screen$ for Palette interrupt changes is unknown to me yet. |-D.
Re: Random Sam BASIC question.
Sorry for the missunderstanding. Anyway, I'm sure that all memory paging ports are read and write ports, bacause there is no other way to determine which bank is currenly paged in. LCD Thomas Harte schrieb: I meant are they read/write, or write only? However in the interim, I've found a copy of the Technical Manual online and discovered that they are read/write, which I wasn't expecting. On 28 Aug 2008, at 21:06, Leszek Chmielewski wrote: 251 = High Memory Page Register 250= Low Memory Page Register Greetings, LCD Thomas Harte schrieb: Port 252 is read/write? Anybody got any idea about ports 250 251? On 28 Aug 2008, at 20:22, Leszek Chmielewski wrote: James R Curry schrieb: Okay, utterly random question... How does one determine the start address of the screen in Sam BASIC? I forget. It has been years. -- James R Curry [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] SAM adv. technical manual says: 10 LET A=IN 252 BAND 31 20 LET BASE=(A+1)*16384 BASE=Start of Screen greetings LCD P.S. But the structure of Information in Screen$ for Palette interrupt changes is unknown to me yet. |-D.
Re: Random Sam BASIC question.
Thomas Harte schrieb: Oh, it was probably my fault for being unclear, since the original question was how do I find out where the screen is and the answer was read port 252, then I guess that raises the presumption that other vague questions are about the function of ports, not whether they're write-only. Yes, but I should read next time more carefully |-D. There are machines with write-only paging registers though. The Acorn Electron is definitely one. But it has a generally painful paging mechanism overall — per the documentation, to get to an arbitrary page, you have to request a page of one of the few ROMs that the keyboard and BASIC ROM can recognise to be not themselves so that they'll release the bus, then do your actual page; it took me ages to find a scheme for my Electron emulator that matched that documented behaviour and the expectations of all the software that just does whatever it feels like. To be honest, I houugh Acorn Electron has the same processor as C64 and Atari XL, and I was sure, they hawe no Ports and anything is memory-mapped (By the way, I currently extending my Retro-X to Acorn Electron and Amiga screen conversion, is your Electron Emulator probably for SAM???). The OS ROM on that machine just keeps a record of the last thing it paged, and juggles as it feels correct when interrupts go. But it also steals about 3.5 kb of a 32 kb machine for various other things, so its help isn't always appreciated. If you substract 10 to 20 Kb for the screen, there is not much left to code... Anyway, the games I have on Beeb suffer from this. Most games use monochrome hires or 4-Colour Fatpix mode. Anyway, blah blah blah, 250/251 being read/write makes some things I was mulling over much easier. I'm hoping to release my 3d wireframe code as a sort of engine for others to use. You just supply an 'update' function and the code builds around it and calls it to do logic and drawing. There's a function call for drawing objects and that's about it. Obviously I'm going to need to be much more careful and open about paging. Releasing your 3D engine for others is a great idea, I saw the Videos on YouTube, I think, you can improve the speed of line drawing by optionaly draw every second pixel of the line on screen (like Mercenary on Speccy). I'm also giving serious consideration to knocking up a quick BASIC dialect to try to increase the code's reach to non-ASM people and make it more likely that some actual titles will be released. But if I manage that then it'll be through a PC/Mac-side compiler rather than any sort of Sam-based interactive environment. Excellent idea (that is something I was planing for Retro-X, but as Cross-Suite, with supply for multiple Machines, with modern BASIC dialect and comfortable Scintilla-Based editor. Unfortunally I was never very good at coding in Z80 assembly, and using ROM Routines), I'm looking forward to see your work, as you are much more gifted coder than I'm. Most importantly, I'm really, really keen to get what I have bundled up so that you don't have to understand it to be able to use it. I understand |-D. LCD On 28 Aug 2008, at 21:23, Leszek Chmielewski wrote: Sorry for the missunderstanding. Anyway, I'm sure that all memory paging ports are read and write ports, bacause there is no other way to determine which bank is currenly paged in. LCD Thomas Harte schrieb: I meant are they read/write, or write only? However in the interim, I've found a copy of the Technical Manual online and discovered that they are read/write, which I wasn't expecting. On 28 Aug 2008, at 21:06, Leszek Chmielewski wrote: 251 = High Memory Page Register 250= Low Memory Page Register Greetings, LCD Thomas Harte schrieb: Port 252 is read/write? Anybody got any idea about ports 250 251? On 28 Aug 2008, at 20:22, Leszek Chmielewski wrote: James R Curry schrieb: Okay, utterly random question... How does one determine the start address of the screen in Sam BASIC? I forget. It has been years. -- James R Curry [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] SAM adv. technical manual says: 10 LET A=IN 252 BAND 31 20 LET BASE=(A+1)*16384 BASE=Start of Screen greetings LCD P.S. But the structure of Information in Screen$ for Palette interrupt changes is unknown to me yet. |-D.
Re: Random Sam BASIC question.
To be honest, I houugh Acorn Electron has the same processor as C64 and Atari XL, and I was sure, they hawe no Ports and anything is memory-mapped (By the way, I currently extending my Retro-X to Acorn Electron and Amiga screen conversion, is your Electron Emulator probably for SAM???). Everything is memory mapped, but it's still registers at addresses, you just use the regular load/store instructions to write to them. The only difference of the z80 versus the 6502 is that it has a 17-bit address, adding a second 64kb can only be accessed by a IN/OUT. My Electron emulator is for the PC/Mac, but I haven't released a new version in years. In any case, if you have any questions about anything on that front, feel free to drop me a line. Releasing your 3D engine for others is a great idea, I saw the Videos on YouTube, I think, you can improve the speed of line drawing by optionaly draw every second pixel of the line on screen (like Mercenary on Speccy). That would definitely help. There's quite a few more things I can do to speed it up without affecting the graphics first though. It's just finding the time. I think I'm relatively lucky because I don't work in anything to do with software so I don't end up with programming fatigue from my real life. I'm also giving serious consideration to knocking up a quick BASIC dialect to try to increase the code's reach to non-ASM people and make it more likely that some actual titles will be released. But if I manage that then it'll be through a PC/Mac-side compiler rather than any sort of Sam-based interactive environment. Excellent idea (that is something I was planing for Retro-X, but as Cross-Suite, with supply for multiple Machines, with modern BASIC dialect and comfortable Scintilla-Based editor. Unfortunally I was never very good at coding in Z80 assembly, and using ROM Routines), I'm looking forward to see your work, as you are much more gifted coder than I'm. Oh, this stuff is all much easier now than it must have been in the 80s. And it's not just the wide array of information that is accessible through the internet, when I was learning 3d I found out that Elite achieves its near-solid look just by using convex objects by directly asking David Braben. Let's not pretend you would have been able to get that sort of help when that sort of information actually had commercial value.
