True. Although with fonts, I only align them with an 8-byte window boundary (to keep the INC L instruction instead of INC HL for speed). That way I only lose seven bytes at most. Besides, I let the assembler worry about where to stick the font. One less thing to worry about.Bizzley wrote: ↑Mon Dec 03, 2018 7:37 pmNot really. As long as you're careful on what specific page boundary you put the font then it's just a matter of changing the LD H,n command to the appropriate value. While there are some values you can't use there are others where you don't need to apply the OR n command at all and can reduce the routine to 15 bytes. It's a bit like setting up interrupt vector tables, you tend to pick something and code around it...well at least I doAst A. Moore wrote: ↑Mon Dec 03, 2018 7:12 pm Hah! Neat. A bit tough to use with custom fonts, though, which was what I initially wrote mine for.
Assembly Help
- Ast A. Moore
- Rick Dangerous
- Posts: 2641
- Joined: Mon Nov 13, 2017 3:16 pm
Re: Assembly Help
Every man should plant a tree, build a house, and write a ZX Spectrum game.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Re: Assembly Help
Thanks for all the replies guys.
Re: Assembly Help
I normally find I have enough 256-byte aligned tables that adding another doesn't actually lose any bytes.Ast A. Moore wrote: ↑Mon Dec 03, 2018 7:46 pmTrue. Although with fonts, I only align them with an 8-byte window boundary (to keep the INC L instruction instead of INC HL for speed). That way I only lose seven bytes at most. Besides, I let the assembler worry about where to stick the font. One less thing to worry about.Bizzley wrote: ↑Mon Dec 03, 2018 7:37 pm Not really. As long as you're careful on what specific page boundary you put the font then it's just a matter of changing the LD H,n command to the appropriate value. While there are some values you can't use there are others where you don't need to apply the OR n command at all and can reduce the routine to 15 bytes. It's a bit like setting up interrupt vector tables, you tend to pick something and code around it...well at least I do
Re: Assembly Help
Aaaaaaaaand, what game are you coding?
Re: Assembly Help
Here's my RST command for Print At. I'm currently using this on the ZX Spectrum Next to check on the number in my sprite rotation.:
Code: Select all
ld a,22 ; Set A with PRINT AT command
rst 10h ; Call
ld a,10 ; Set A with 7 (Y coord)
rst 10h
ld a,10 ; Set A with 8 (X coord)
rst 10h
ld a,0
ld a,(rightplayer)
ld bc,0
ld c,a
call 6683
Re: Assembly Help
Its a simple platform game. Nothing that will shake the world, but I try and get back to developing it when I can.
Re: Assembly Help
Hi Peter - I know the feeling! Six months ago I was in a similar position to you and a bit rusty on the Z80 having not touched it since the early 1990s. But it's funny how quickly it comes back. Really enjoyable to be back on this 8-bit processor.
Good luck completing your game!
Cosmium
Cosmium
https://cosmium.itch.io/
https://cosmium.itch.io/