Spectrum Computing

Patrik Rak

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...

Patrik Rak

I did, even the original post, but that really doesn't explain the point, IMO, why was this change worth it.

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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?

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

Fair enough.

Patrik Rak

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.

Patrik

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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...

Patrik Rak

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.

Patrik Rak

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...

Patrik Rak

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

Patrik Rak

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...

Patrik Rak

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

Patrik Rak

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...

Patrik Rak

GitHub repo: https://github.com/MrKWatkins/ZXSpectrumNextTests/tree/develop/Tests/ZX48_ZX128/Z80BlockInstructionFlags Hmm, looks like the test doesn't cover any of the cases where the half carry flag is set after I/O instructions. Could we have those, too? Both the 15->16 and 16->15 transitions wou...

Spectrum Computing

Search found 116 matches

Re: New Database Model ZXDB

Re: New Database Model ZXDB

Re: New Database Model ZXDB

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

Re: ZXDS 2.2.2 and 1.4.1

Re: ZXDS 2.2.2 and 1.4.1

ZXDS 2.2.2 and 1.4.1

Re: That thing with the bottom two lines

Re: Contention pattern for HALT

Re: How hard is it to write an emulator?

Re: Contention pattern for HALT

Re: Contention pattern for HALT

Re: Contention pattern for HALT

Re: Contention pattern for HALT

Re: Contention pattern for HALT

Re: Contention pattern for HALT

Re: New discovery on Z80 I/O block instructions

Re: Modern Sprite Editor

Re: my first ASM program lol

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

Re: PlayTZX

ZXDS 1.4.0

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

Re: ZXDS 2.2.0

Re: Z80 Block Flags Test for the "recently" discovered behavior of the block instructions of the Z80 CPU