Search found 207 matches

by ketmar
Wed Aug 26, 2020 3:53 am
Forum: Programming
Topic: Screen memory
Replies: 16
Views: 726

Re: Screen memory

as it was said somewhere else ;-), screen address pattern is actually very simple. in binary it looks like this: 010hhzzz yyyxxxxx here: xxxxx -- 5-bit x coordinate. this gives us [0..#1F] in hex, or [0..31] in dec. zzz -- vertical coordinate in character cell (that's what you're changing by `inc h`...
by ketmar
Tue Aug 25, 2020 8:22 am
Forum: Programming
Topic: Screen memory
Replies: 16
Views: 726

Re: Screen memory

Ast A. Moore wrote:
Tue Aug 25, 2020 7:58 am
Very clever, indeed! Unfortunately, that would be difficult to maintain for a custom font, especially if it loaded at an arbitrary address.
yeah. but your routine seem to use hard-coded ROM address anyway, so in this special case it fits. ;-)
by ketmar
Tue Aug 25, 2020 7:28 am
Forum: Programming
Topic: Screen memory
Replies: 16
Views: 726

Re: Screen memory

Would it help to first do an add a,a then ld l,a, and do without the first add hl,hl? I think add a,a is a tad faster than Add hl,hl. That's if you don't mind disrupting the contents of A. yeah, if you don't need A to be preserved (which is usually the case at this stage), then your version is even...
by ketmar
Tue Aug 25, 2020 3:44 am
Forum: Programming
Topic: Screen memory
Replies: 16
Views: 726

Re: Screen memory

smaller and faster ROM character address calculation, BC is not used. ;-)

Code: Select all

  ld   l,a
  add  hl,hl
  ld   h,15
  add  hl,hl
  add  hl,hl
by ketmar
Sun Aug 23, 2020 8:45 am
Forum: Showcase your work!
Topic: dsForth/TR-DOS
Replies: 27
Views: 1646

Re: dsForth/TR-DOS

the huge delay with new release is due to... oh... i spent last week writing x86 forth from scratch , in asm and forth. ;-) UrAsm already has UrForth built in, but it becomes more and more limiting to have forth built into assembler, and not vice versa. ;-) the plan is to create a full-featured cros...
by ketmar
Sat Aug 22, 2020 3:40 pm
Forum: Other Retro Stuff
Topic: Manic Miner 3D
Replies: 10
Views: 844

Re: Manic Miner 3D

Show me on the doll where the nasty developer hurt you. you prolly didn't noticed that, but i didn't said a word about the dev. so, if i don't like something, and explained why exactly i don't like it (slightly too expressive, maybe), it always means that i HAET THE DEV HE HURTED ME OH NOES? p.s.: ...
by ketmar
Sat Aug 22, 2020 1:25 am
Forum: Programming
Topic: Z80 asm/disasm in Z80 asm [solution found]
Replies: 14
Views: 865

Re: Z80 asm/disasm in Z80 asm [solution found]

managed to strip out 30 bytes from assembler, and add "division by zero" check. less is more! ;-)
by ketmar
Sat Aug 22, 2020 12:52 am
Forum: Games/Software
Topic: The best modern Speccy game beginning with Q: vote
Replies: 8
Views: 510

Re: The best modern Speccy game beginning with Q: vote

how come nobody loves the best game of the decade (and maybe of all times), Quantum Gardening?!
by ketmar
Sat Aug 22, 2020 12:39 am
Forum: Games/Software
Topic: Battle 1917
Replies: 12
Views: 593

Re: Battle 1917

sorry, i cannot say anything ontopic, but oh, the memories! i used to play this game for hours, and your post brought those great memories back...
by ketmar
Sat Aug 22, 2020 12:27 am
Forum: Other Retro Stuff
Topic: Manic Miner 3D
Replies: 10
Views: 844

Re: Manic Miner 3D

and now we need unreal engine and multigigabyte-multigigahertz gpus/cpus to play Manic Miner, that worked on 8-bit machine with 48K memory, and 3.5MHz clock. the quintessense of modern gaming. p.s.: and the game itself is giving me an instant vertigo. all the expirience with 3d platforming is wasted...