Thanks for that advice Gavin - I loaded up XROAR and eventually got it all going - what a hoot! It really looks and sounds the goods. I wasn't able to get through right to the end but I guess after 25 years I can be excused for losing the knack! I recall it was very finicky getting the timing right and placing Horrace in exactly the right place to attract the guards to a position where a dash to the finish was just barely possible. Wish I could remember the tricks.
I vaguely recall that other games being developed at MH at the time did direction validity testing by probing in the adjacent cells of the map whereas in the Dragon HH I encoded the valid directions in the top nibble of the map so a single boolean op could determine if the direction key being pressed would cause a direction change. There was some mechanism that let me view the "rails" that I though of Horrace as running on by making this top nibble visible in the graphic display - I'm almost certain that I disabled the "cheat" key but the code and necessary graphics were not conditionally removed from the assembly as best I recall so a flag flip would probably activate all this again. Can't remember if there were other cheat codes but I vaguely recall a whole line of Horraces waiting up at the top of the screen tapping their feet... such a long time ago - wish I'd though to keep an assembly listing. I must do some searching and see if I can work out how to disassemble the code and try to recall what was going on.
I can remember that I had a lot of fun with the Dragon sound that didn't make it into Horrace - there was an article in a US CoCo magazine that showed a very clever way of playing multiphonic voices. Basically it involved a 256 entry waveform table and a clever trick with using 16-bit aritmetic to determine the offset into the waveform table in the high byte ensuring accurate pitches. Up to three voices were easy to accomodate under interrupt control - I think the sound was based on the high bit of the sum of the voice amplitudes somehow... can't quite recall the details. You could clearly hear the different voices. I ended up encoding a bunch of slip jigs from O'Neils Music of Ireland... Didn't fit into the Horrace scenario so we had pretty simple sounds in the end. If any 6809 coders out there collect CoCo magazines from that time I would sure like to read through the code in that article again!
Thanks also for the kind offer of a Dragon - I'll give that some thought. I need to read up a bit on what power supplies and cables I need and so forth - maybe a PSP would do me. I must confess I don't have a lot of particular nostalgia for the Dragon machine itself (sorry if that offends anyone here) as I was never much of a game player myself and I only had access to a Dragon right at the end of the development cycle (I think I actually developed the code on a CoCo under OS9? Does that sound right?). I do have nostalgia for a whole raft of CPUs of that time though - almost anything seemed possible then in a way that C# or Java just don't do it for me now. Had lots of fun with the 6502 and 68000 also, though I never cottoned to the Z80 much.
I recall the time at MH with quite a bit of fondness, even though I left under a cloud (I developed a bad attitude and worked quite hard to get myself sacked - the first and last time in my life). We worked on lots of cool stuff and there were some really interesting people working there at the time.
Thanks also for all the other comments.
Cheers, Dieter.
Hello
Re:
Check the CoCo3.com forums Misc. Topics area.djansen wrote:I can remember that I had a lot of fun with the Dragon sound that didn't make it into Horrace - there was an article in a US CoCo magazine that showed a very clever way of playing multiphonic voices. Basically it involved a 256 entry waveform table and a clever trick with using 16-bit aritmetic to determine the offset into the waveform table in the high byte ensuring accurate pitches. Up to three voices were easy to accomodate under interrupt control - I think the sound was based on the high bit of the sum of the voice amplitudes somehow... can't quite recall the details. You could clearly hear the different voices. I ended up encoding a bunch of slip jigs from O'Neils Music of Ireland... Didn't fit into the Horrace scenario so we had pretty simple sounds in the end. If any 6809 coders out there collect CoCo magazines from that time I would sure like to read through the code in that article again!
And please don't post new links to the files. The person that scanned most of them wants to keep them off search engines.
Simon Hardy
Re: Hello
If you let me know what year the magazine was from I might be able to tell you what issue.
There was a pretty good article on sound in a 1984 Rainbow, Color Computer News had the William Tell Overture in 4 voice music (non interrupt driven) and Color Computer Magazine had a good article in 1983 or 1984 as well. I think the Rainbow issue had 'Zounds Sounds' somewhere on the cover.
There was a Christmas (Dec) issue of Rainbow that had Christmas music played with bells. (Kitzmas Carols? 1985?)
There was a pretty good article on sound in a 1984 Rainbow, Color Computer News had the William Tell Overture in 4 voice music (non interrupt driven) and Color Computer Magazine had a good article in 1983 or 1984 as well. I think the Rainbow issue had 'Zounds Sounds' somewhere on the cover.
There was a Christmas (Dec) issue of Rainbow that had Christmas music played with bells. (Kitzmas Carols? 1985?)
Simon Hardy
Re: Hello
I presume this regards the links I gave, I now have a problem accessing the old forum so have removed the links. Anyway, if memory serves, Sixxie's explanation is that this site's .cas file of Juxtaposition was originally made for emulators that did not bother with tape timing issues (periods of silence), so to create the smallest .cas files possible the .cas creation tools of the time stripped out the periods of silence. The latest versions of XRoar (as well as real Dragons) do expect the periods of silence, this site's .cas file of Juxtaposition has been altered by extending the period of silence before the tape loading screen but no period has been inserted between the loading screen and the program proper, thus the game fails to load.shutty wrote:If only I could read them! I don't seem to have the required access permissions.
P.S This is getting off the topic of this thread, if you wish to continue then please start a new thread.
P.P.S. Admin, I think I have Sixxie's altered version of Juxtaposition around, I'll upload it if you wish.
Re: Hello
Weird that I removed it - most stuff in that directory hangs around forever.
I re-uploaded, anyway: JUXTAPOS2.CAS.
I re-uploaded, anyway: JUXTAPOS2.CAS.
Re: Hello
The Dec issue with Kitzmas Carols was a 'Color Computer Magazine' issue and it had some rather complex sound generation stuff.JamesD wrote:If you let me know what year the magazine was from I might be able to tell you what issue.
There was a pretty good article on sound in a 1984 Rainbow, Color Computer News had the William Tell Overture in 4 voice music (non interrupt driven) and Color Computer Magazine had a good article in 1983 or 1984 as well. I think the Rainbow issue had 'Zounds Sounds' somewhere on the cover.
There was a Christmas (Dec) issue of Rainbow that had Christmas music played with bells. (Kitzmas Carols? 1985?)
<edit>
There was also a Dec '85 issue of Rainbow that had the Christmas music I mentioned.
That issue is available for download if you look over on the CoCo3.com forums in the welcome area. You will need an account to access the forums.
Simon Hardy