SarahJaneAvory
@sarahjaneavory.bsky.social
#Writer, #coder. Code C64 games in my spare time. Released my #BrileyWitch #C64 #RPG via http://itch.io. Also owner of 3 cats.
https://sarahjaneavory.itch.io/
https://sarahjaneavory.itch.io/
Pinned
For those that don't know, I started programming in the 80s on machines like Commodore VIC20 and C64... and after a lifetime of programming all sorts of consoles and computers, my spare time is now spent making C64 games... and it's a lot of fun!😃🥰
Spectrum Next #Delphian progress: coded up the clipped circle draw code in C++ over lunch, so coded up the Z80 version this evening. Good news is it's working, and it's fast!😀 So if I code up dithered "transparent" versions (like Amiga Thunderhawk), I could use it for smoke and other effects...🤔
November 24, 2025 at 9:24 PM
Spectrum Next #Delphian progress: coded up the clipped circle draw code in C++ over lunch, so coded up the Z80 version this evening. Good news is it's working, and it's fast!😀 So if I code up dithered "transparent" versions (like Amiga Thunderhawk), I could use it for smoke and other effects...🤔
Spectrum Next #Delphian progress: with a bit of movement code added, this is starting to feel like a game...😀 But I definitely need to add the radar display! (adds to To-Do list) As for ship AI, I think I can handle that okay. I did code a lot of ship AI for Elite: Dangerous after all...😉
November 21, 2025 at 10:26 PM
Spectrum Next #Delphian progress: with a bit of movement code added, this is starting to feel like a game...😀 But I definitely need to add the radar display! (adds to To-Do list) As for ship AI, I think I can handle that okay. I did code a lot of ship AI for Elite: Dangerous after all...😉
Spectrum Next #Delphian progress: added a linked polygon system so that I can link surface detail to a polygon. Also added support for 5-sided polygons. Rearranged some memory too, so models are now in their own bank. Oh, and added some quick lasers too! Next step might be to make ships move...
November 20, 2025 at 9:31 PM
Spectrum Next #Delphian progress: added a linked polygon system so that I can link surface detail to a polygon. Also added support for 5-sided polygons. Rearranged some memory too, so models are now in their own bank. Oh, and added some quick lasers too! Next step might be to make ships move...
Spectrum Next #Delphian progress: I have my own 3D model editor, so it's been upgraded to output for my game.🥰 Means I can now build a lot of 3D models. I've also optimised the 3D engine code a little too. Should be able to post a new video soon 'cos everyone loves a new video, right?😉
November 19, 2025 at 11:34 PM
Spectrum Next #Delphian progress: I have my own 3D model editor, so it's been upgraded to output for my game.🥰 Means I can now build a lot of 3D models. I've also optimised the 3D engine code a little too. Should be able to post a new video soon 'cos everyone loves a new video, right?😉
Spectrum Next #Delphian progress: polygon sorting is now in and working.🙂 Had it working one way, and then while taking a bath, came up with a better more efficient method. Also optimised the screen clear (actually fixed a silly bug) so it's now twice as fast.😀
November 13, 2025 at 10:19 PM
Spectrum Next #Delphian progress: polygon sorting is now in and working.🙂 Had it working one way, and then while taking a bath, came up with a better more efficient method. Also optimised the screen clear (actually fixed a silly bug) so it's now twice as fast.😀
Bit of a rough day emotionally today. It would've been my partner's birthday. Took the day off work as I knew it was going to be rough. Z80 coding can only distract me so much. I'm learning new stuff, but I have no one here to tell... Rough day.
November 10, 2025 at 1:32 PM
Bit of a rough day emotionally today. It would've been my partner's birthday. Took the day off work as I knew it was going to be rough. Z80 coding can only distract me so much. I'm learning new stuff, but I have no one here to tell... Rough day.
Spectrum Next #Delphian progress: fixed a few bugs in my clipping code so all is good now. So added view culling of objects, as well as support for multiple 3D objects. Also added the object sort so distant objects are draw behind near ones. Still need to add polygon sorting, so that's next.
November 9, 2025 at 11:07 PM
Spectrum Next #Delphian progress: fixed a few bugs in my clipping code so all is good now. So added view culling of objects, as well as support for multiple 3D objects. Also added the object sort so distant objects are draw behind near ones. Still need to add polygon sorting, so that's next.
Spectrum Next #Delphian progress: been happily optimising code, then was having an insane random crash that exploded the screen...😮 Took a couple of hours to track down... Turns out it's not a good idea to use an LDI instruction inside a DJNZ loop without protection. Z80 lesson learned.
November 9, 2025 at 4:41 PM
Spectrum Next #Delphian progress: been happily optimising code, then was having an insane random crash that exploded the screen...😮 Took a couple of hours to track down... Turns out it's not a good idea to use an LDI instruction inside a DJNZ loop without protection. Z80 lesson learned.
Spectrum Next #Delphian progress: added fully clipped 3D lines, and also added movement code so I can now fly around my object in space.☺️ Next comes polygon sorting per object, and then object sorting. I also need to add code to reject objects outside the view cone. Still, I'm making progress...☺️
November 8, 2025 at 10:44 PM
Spectrum Next #Delphian progress: added fully clipped 3D lines, and also added movement code so I can now fly around my object in space.☺️ Next comes polygon sorting per object, and then object sorting. I also need to add code to reject objects outside the view cone. Still, I'm making progress...☺️
Spectrum Next #Delphian progress: so clipped quad and tri polygons are now fully working.😎 I can probably optimise the code a bit further... Best thing is: not a single divide anywhere. All done with multiplies ('cos Spectrum Next has a handy 8 cycle MUL instruction).🥰 Next step: 3D line draw.
November 7, 2025 at 9:59 PM
Spectrum Next #Delphian progress: so clipped quad and tri polygons are now fully working.😎 I can probably optimise the code a bit further... Best thing is: not a single divide anywhere. All done with multiplies ('cos Spectrum Next has a handy 8 cycle MUL instruction).🥰 Next step: 3D line draw.
Spectrum Next #Delphian progress: got unclipped quad polygon rendering working during my lunch hour. Also cleaned up the code to support both tri and quad polygons. This evening (hopefully): fully clipped polygons.🙂
November 5, 2025 at 3:48 PM
Spectrum Next #Delphian progress: got unclipped quad polygon rendering working during my lunch hour. Also cleaned up the code to support both tri and quad polygons. This evening (hopefully): fully clipped polygons.🙂
Spectrum Next #Delphian progress: working on the 3D engine. unclipped triangles are now working. It's using DMA to fill lines, and just CPU on short lines. Some more optimisations to be done, but at least it's working. Next comes all the clipped polygons!🙂 No problemo!😉
November 4, 2025 at 9:04 PM
Spectrum Next #Delphian progress: working on the 3D engine. unclipped triangles are now working. It's using DMA to fill lines, and just CPU on short lines. Some more optimisations to be done, but at least it's working. Next comes all the clipped polygons!🙂 No problemo!😉
Penny Lane wants something... The joy of having cats. I'm working, they want attention. When I'm free, they're all sleeping. Gotta love 'em though. ❤️
November 4, 2025 at 11:46 AM
Penny Lane wants something... The joy of having cats. I'm working, they want attention. When I'm free, they're all sleeping. Gotta love 'em though. ❤️
Spectrum Next #Delphian progress: porting my 3D code from PC to Z80. Object rotate and vertex transform and projection code in and working, and just finished back face culling. Some specialised maths code in there for max speed. Next step: start coding the clipped triangle/quad render code. Easy.😎
November 3, 2025 at 10:54 PM
Spectrum Next #Delphian progress: porting my 3D code from PC to Z80. Object rotate and vertex transform and projection code in and working, and just finished back face culling. Some specialised maths code in there for max speed. Next step: start coding the clipped triangle/quad render code. Easy.😎
Spectrum Next #Delphian progress: been busy working on a 3D polygon engine. I've prototyped the system in C++ on the PC (clipped tri/quad rendering plus 3D maths), so now comes the fun part of converting it all to Z80!🙂 I wrote the C++ code so it would port easy, so hopefully this won't take long...
November 3, 2025 at 5:17 PM
Spectrum Next #Delphian progress: been busy working on a 3D polygon engine. I've prototyped the system in C++ on the PC (clipped tri/quad rendering plus 3D maths), so now comes the fun part of converting it all to Z80!🙂 I wrote the C++ code so it would port easy, so hopefully this won't take long...
It's my birthday today, and I have the day off.🙂 Since I've been doing Z80 coding recently, that must mean: LD HL,sarah_age ; INC (HL).😉
October 30, 2025 at 8:41 AM
It's my birthday today, and I have the day off.🙂 Since I've been doing Z80 coding recently, that must mean: LD HL,sarah_age ; INC (HL).😉
Halloween approaches🧙♀️, so that must mean my C64 games are on sale!🙂🧹🎃
itch.io/s/165702/sja...
itch.io/s/165702/sja...
SJA's Halloween Sale 2025 by SarahJaneAvory
A bundle by SarahJaneAvory, $26.94 for 6 games
itch.io
October 28, 2025 at 8:39 PM
Halloween approaches🧙♀️, so that must mean my C64 games are on sale!🙂🧹🎃
itch.io/s/165702/sja...
itch.io/s/165702/sja...
For Delphian on Spectrum Next I was going to do everything as sprites, but now I'm thinking of using filled 3D polygons to do the ships, and perhaps even the buildings...🤔
October 28, 2025 at 10:16 AM
For Delphian on Spectrum Next I was going to do everything as sprites, but now I'm thinking of using filled 3D polygons to do the ships, and perhaps even the buildings...🤔
Spectrum Next #Delphian progress: WIP from walking around to going into space, and returning to the surface. it's a bit rough in places, but it's still progress so I'm happy.🙂
October 26, 2025 at 2:40 PM
Spectrum Next #Delphian progress: WIP from walking around to going into space, and returning to the surface. it's a bit rough in places, but it's still progress so I'm happy.🙂
Now I'm living alone, I have all the time in the world, but most days I just don't want to do anything. I'm sure my motivation will return one day. After all, I have several coding projects that need completing so that others can play (and hopefully enjoy) them.
October 24, 2025 at 9:11 PM
Now I'm living alone, I have all the time in the world, but most days I just don't want to do anything. I'm sure my motivation will return one day. After all, I have several coding projects that need completing so that others can play (and hopefully enjoy) them.
I've not done much retro coding recently for personal reasons... but have made a small amount of progress on Spectrum Next Delphian. In fact, I might be able to post another short video soon...
October 24, 2025 at 9:06 PM
I've not done much retro coding recently for personal reasons... but have made a small amount of progress on Spectrum Next Delphian. In fact, I might be able to post another short video soon...
A mention of one of my old games... 🙂
www.topgear.com/car-news/gam...
www.topgear.com/car-news/gam...
www.topgear.com
October 24, 2025 at 9:02 PM
A mention of one of my old games... 🙂
www.topgear.com/car-news/gam...
www.topgear.com/car-news/gam...
Spectrum Next #Delphian progress: from walking around to flying across a planet, to flying into space... Now I just need to optimise the starfield code a little... then add the planets and the sun when in space. Still, I'm making progress... 😀😎
October 7, 2025 at 6:58 PM
Spectrum Next #Delphian progress: from walking around to flying across a planet, to flying into space... Now I just need to optimise the starfield code a little... then add the planets and the sun when in space. Still, I'm making progress... 😀😎