Search found 117 matches

by Patrik Rak
Fri Apr 19, 2024 4:26 pm
Forum: ZXDB Discussion
Topic: New Database Model ZXDB
Replies: 536
Views: 108538

Re: New Database Model ZXDB

Because it's an automatically generated field. ... ZXDB follows the latter option. Whenever an information is automatically generated, then it's not part of the ZXDB "source code" distribution. Instead it's dynamically generated by scripts. You could just as well run the scripts and distr...
by Patrik Rak
Wed Apr 10, 2024 2:18 pm
Forum: ZXDB Discussion
Topic: New Database Model ZXDB
Replies: 536
Views: 108538

Re: New Database Model ZXDB

I mean, if you want to group the games by letter reasonably, you need the library title without the articles. In order to be able to search them efficiently in the database, you will have to have the field ready in some form in one way or another, be it in another table or not. So I don't see the po...
by Patrik Rak
Wed Apr 10, 2024 2:14 pm
Forum: ZXDB Discussion
Topic: New Database Model ZXDB
Replies: 536
Views: 108538

Re: New Database Model ZXDB

I did, even the original post, but that really doesn't explain the point, IMO, why was this change worth it.
by Patrik Rak
Wed Apr 10, 2024 2:07 pm
Forum: ZXDB Discussion
Topic: New Database Model ZXDB
Replies: 536
Views: 108538

Re: New Database Model ZXDB

Late to the party, but why was the library_title removed in the first place? Just to save space? Couldn't have it been simply null when it doesn't differ from the title? As for the provided SQL scripts, unfortunately none worked for me out of the box, not even Skoolkids, perhaps my sqlite is older t...
by Patrik Rak
Wed Apr 10, 2024 1:20 pm
Forum: Other Retro Stuff
Topic: any suggestion for a good portable device that can play zx spectrum games?
Replies: 10
Views: 310

Re: any suggestion for a good portable device that can play zx spectrum games?

Probably best not to try a 3DS as then you have to check closely which version of firmware it has compared to what version of R4 card you're using, as it's smarter at blocking attempts to hack it. And they're not as cheap as an old DS anyway. And the 3DS-XL has a different resolution on the top scr...
by Patrik Rak
Wed Mar 20, 2024 8:42 am
Forum: Emulators
Topic: ZXDS 2.2.2 and 1.4.1
Replies: 9
Views: 495

Re: ZXDS 2.2.2 and 1.4.1

First of all, are we talking about DS or 3DS version? How do you transfer the files? Also, if you deleted them (how?) but they still show up, there must be something really weird going on. Are you sure that the filesystem on your SD card is not corrupt in some way? The directory is reloaded every ti...
by Patrik Rak
Tue Mar 19, 2024 6:01 pm
Forum: Emulators
Topic: ZXDS 2.2.2 and 1.4.1
Replies: 9
Views: 495

Re: ZXDS 2.2.2 and 1.4.1

blucey wrote: Sat Mar 16, 2024 9:21 pm it won't load up any of my z80 files (it crashes all of them)
If you can share one, I guess I can have a look. Knowing how were those z80 created might help, too. Also, do they work in other emulators?
by Patrik Rak
Sat Feb 24, 2024 5:17 pm
Forum: Emulators
Topic: ZXDS 2.2.2 and 1.4.1
Replies: 9
Views: 495

ZXDS 2.2.2 and 1.4.1

Hello, New releases of both 3DS and NDS versions of ZXDS are out. The changes are relatively small, most notably fixing the AY clock frequency so it is exactly half the CPU clock frequency, and solving the troubles with RZXs with mismatched TR-DOS ROMs, but I hope that some people will enjoy it neve...
by Patrik Rak
Wed Feb 21, 2024 11:27 am
Forum: Programming
Topic: That thing with the bottom two lines
Replies: 19
Views: 799

Re: That thing with the bottom two lines

BTW, I always found it interesting that many of the early loading screens didn't use those lines, as apparently the tools used to create them couldn't draw there either. It took several years before programs like The Artist or Art Studio appeared and full-screen loading screens became the norm. What...
by Patrik Rak
Sun Feb 18, 2024 11:12 am
Forum: Programming
Topic: Contention pattern for HALT
Replies: 25
Views: 1434

Re: Contention pattern for HALT

Fair enough.
by Patrik Rak
Sun Feb 18, 2024 11:02 am
Forum: Emulators
Topic: How hard is it to write an emulator?
Replies: 21
Views: 1011

Re: How hard is it to write an emulator?

Jbizzel wrote: Wed Oct 25, 2023 9:13 pm ...and how many hours of work is it for a skilled coder?
I had mine running on the first weekend. First properly usable public release in few months. Then after 15 years it's pretty complete. YMMV, though. :D

Patrik
by Patrik Rak
Sun Feb 18, 2024 10:55 am
Forum: Programming
Topic: Contention pattern for HALT
Replies: 25
Views: 1434

Re: Contention pattern for HALT

sadly, this doesn't quite work if you need a sophisticated breakpoint system. Why not check if it can be done or not? For example, my HALT checks if the reads need to be contended and if not it uses simple modulo 4 to compute the remaining T cycles. Otherwise it does the contended fetches in a loop...
by Patrik Rak
Sun Feb 04, 2024 2:28 pm
Forum: Programming
Topic: Contention pattern for HALT
Replies: 25
Views: 1434

Re: Contention pattern for HALT

I handle it differently. I have a special loop for the HALT state. I also consume all the remaining T-cycles in the HALT itself. The re-execution happens only afterwards if needed (i.e., unless the HALT state is finished by accepting IRQ). This allows me to emulate parts of the frame efficiently, w...
by Patrik Rak
Tue Jan 23, 2024 8:25 pm
Forum: Programming
Topic: Contention pattern for HALT
Replies: 25
Views: 1434

Re: Contention pattern for HALT

if I remember well, it was concluded that emulators should continue storing the PC which points to halt instruction , regardless of how the behaviour is internally implemented in particular emulator. And when loading from snapshots, if halt flag is set in snapshot, an emulator should assume that st...
by Patrik Rak
Sun Jan 21, 2024 11:18 am
Forum: Programming
Topic: Contention pattern for HALT
Replies: 25
Views: 1434

Re: Contention pattern for HALT

Are the contents of PC+1 continually fetched (with contention pattern pc:4 there too) while the processor is HALTed? From what you're saying, this looks like a bug in Fuse to me. Or I'm misunderstanding. Yes, it's continually fetched and contended. As for Fuse, it might have been fixed in newer ver...
by Patrik Rak
Sun Jan 21, 2024 11:11 am
Forum: Programming
Topic: Contention pattern for HALT
Replies: 25
Views: 1434

Re: Contention pattern for HALT

is it really like that? i was sure that Z80 keeps reading the memory. that explains why HALT is not ts-precise (i.e. CPU checks for /INTR each 4ts instead of each 1ts). it would be logical to either just loop and check for /INTR (and /NMI) on each tick if there is no command fetching — or make HALT...
by Patrik Rak
Fri Jan 19, 2024 5:50 pm
Forum: Programming
Topic: Contention pattern for HALT
Replies: 25
Views: 1434

Re: Contention pattern for HALT

Based on what I've already learnt, I'm guessing that HALT's contention pattern is simply pc:4 . Can anyone confirm? Only the first fetch of the HALT itself. Then it executes NOPs internally, with PC already being PC+1. (So it's not like it keeps executing itself similar to LDIR, which is what peopl...
by Patrik Rak
Sat Dec 02, 2023 1:25 pm
Forum: Emulators
Topic: New discovery on Z80 I/O block instructions
Replies: 15
Views: 1765

Re: New discovery on Z80 I/O block instructions

i dont remember old discussions details now, but do you mean even Patrik himself never tried it on a real hw :? There was so many people testing the interrupted flags on the real hardware, using both mine and Ped7g's tests, that it never occurred to anyone the memptr behavior was not tested. Appare...
by Patrik Rak
Sun Nov 13, 2022 1:05 pm
Forum: Graphics
Topic: Modern Sprite Editor
Replies: 11
Views: 736

Re: Modern Sprite Editor

No, on ZXDS that (lower) touch screen shows the Speccy keyboard and the load/save/config menus Well, if it supported kempston mouse, you could paint with the stylus. Some of the provided mouse modes even bring the top screen to the bottom when activated, so you can draw exactly at where you touch t...
by Patrik Rak
Wed Sep 07, 2022 2:35 pm
Forum: Programming
Topic: my first ASM program lol
Replies: 75
Views: 2271

Re: my first ASM program lol

Jbizzel wrote: Sun Sep 04, 2022 8:31 pm Well, I've been messing about in ASM and actually managed to compile something using Pasmo. Its not very exciting, but its a start.
You are doing fine. I am pretty sure that my very first assembler program was just a single RET. :D
by Patrik Rak
Fri Jun 10, 2022 5:30 pm
Forum: Emulators
Topic: z80test with LDxR->NOP' and INxR->NOP'
Replies: 3
Views: 319

Re: z80test with LDxR->NOP' and INxR->NOP'

These tests are set up in such a way that the instruction overwrites itself, effectively turning the instruction into ED prefixed NOP. This in turn has the effect that it reveals how flags are set in case the instruction repeats itself, rather than how they are set when it finishes. Similar test was...
by Patrik Rak
Wed May 04, 2022 4:01 pm
Forum: Emulators
Topic: PlayTZX
Replies: 4
Views: 499

Re: PlayTZX

TMD2003 wrote: Mon May 02, 2022 2:29 pm Does anyone know what the latest version of PlayTZX is, or where to get it?
Unless you need PlayTZX as such, you can also use the PZX Tools and do

Code: Select all

tzx2pzx file.tzx | pzx2wav | play
or something along those lines.

Patrik
by Patrik Rak
Sat Apr 23, 2022 7:14 am
Forum: Emulators
Topic: ZXDS 1.4.0
Replies: 2
Views: 275

ZXDS 1.4.0

Hello, to celebrate the 40th Spectrum anniversary, and the 15th anniversary of ZXDS itself, I have released new update of ZXDS for the original DS . It brings most of the features from the 3DS version which were implemented during the past few years. Of course, some unique features were impossible t...
by Patrik Rak
Thu Jan 20, 2022 5:37 pm
Forum: Programming
Topic: How to read the keyboard and joystick at the same time
Replies: 22
Views: 1139

Re: How to read the keyboard and joystick at the same time

Bubu wrote: Thu Jan 20, 2022 4:54 pm The thing is that I don't want the gamer have to choose his/her device method.
Check what Zynaps does - it automatically switches to whichever joystick you use. It can even toggle between cursor and sinclair joystick depending on if you press 5 or 9, respectively.

Patrik
by Patrik Rak
Thu Jan 06, 2022 3:14 pm
Forum: Emulators
Topic: ZXDS 2.2.0
Replies: 4
Views: 461

Re: ZXDS 2.2.0

As I understand it, the owners of NDS do not have to hope for an update and use the 5-year-old version 1.3.4?? With the recent updates to the Z80 CPU emulation cores regarding block instructions, I am intending to update the original NDS version as well and backport some of the fixes from the 3DS v...