Spectrum Computing

E.g. I want to poke a 255 value into the pixel y=132, then instead of calling a routine, that occupies memory and cycles of CPU, I only have to do this: ld a, 255 ld hl, ( 132 >> 3) | ( 132 & 7) | 64) * 256 + ( 132 << 2) & 224) ld (hl), 255 Obviuosly this is only useful when I know the &quo...

You can indeed use a hex editor for any files. Just keep in mind that editing TAP and TZX files will affect the checksum, which will have to be recalculated. For tape blocks that use the standard XOR method for the checksum byte, I find Tapir to be very convenient. It’ll highlight the offending bloc...

When I load a .tzx using ZXSP, for example Saboteur (1986) , the emulator loads it automatically and skips the loading screen altogether. Since a TZX is a perfect representation of a tape, it can very well be a tape that uses bog-standard ROM loading routines. Then it’s no different than a TAP file...

Yes, I’d give Tapir a try. It generates a waveform that is very close to what a real Spectrum would produce.

Wait, there’s Easter this year too? Bloody hell. I thought it was just a 2021 thing.

Just to let you know, I haven’t had any issues accessing SC on any of my devices from different locations.

MrBitey wrote: ↑Mon Feb 14, 2022 9:49 am Thanks very much. That helped me to find the answer.
I was loading Z80 files.

Yes, some snapshots retain (and load) a certain amount of machine configuration. That’s why I generally avoid them, because they mess up my settings.

MrBitey wrote: ↑Mon Feb 14, 2022 9:49 am BTW, 'A Yankee in Iraq' is great!

Thanks!

I’m still on 10.14, but you need to restart the emulated machine for the Kempston interface setting to have an effect. The reason it looks like the joystick is stuck is that with no Kempston interface attached, every bit of the port reads high. This essentially means that every direction and the fir...

p13z wrote: ↑Sat Feb 12, 2022 9:40 pm This is in relation to replacing the speaker in a Fergy tape player though.

D’oh! I completely missed that!

In that case, yeah, a 1W 8Ω speaker will do just fine.

Add “/releases” to the project’s GitHub URL, and it should become pretty self-explanatory.

I just realized something. The Spectrum’s speaker has an impedance of 40Ω, and nowhere near 0.5W. So, if you’re connecting an 8Ω speaker to the emitter of TR7, you might be pushing too much current through it and you’ll need to limit it anyway.

mausthekat wrote: ↑Sat Feb 12, 2022 12:26 am

Ast A. Moore wrote: ↑Sun Jan 02, 2022 11:34 pm
EDIT: Never mind. Found it. Thanks!

Where did you find it?

Oh, from the pinned message in that Telegram channel. Turns out you don’t have to join it to see link.

If you search GitHub for “Vortex Tracker,” it’s the second hit from the top.

I think it’ll be okay with a 8.2Ω resistor in series.

When I got my Toastrack, I had to replace the membrane twice. The first one was a dud with a visible break in the conductive-paint trace. The replacement had a sticky “5” key. Massaging it gently for a few minutes fixed the problem and it’s been working fine ever since. The Plus model (and the Toast...

Because I cannot use Photoshop anymore I'm struggling to change the resulting .gifs that zxsp makes for my usage. What do you intend to change them to? Preview will open any GIF file. If you want a more refined tool, then https://ezgif.com/maker is a good start. I big issue I still have is how to c...

dfzx wrote: ↑Thu Feb 03, 2022 12:35 pm Nervos This Position

Yes!

Made y’all nervos, eh?

Okay. Final “clue”:

tolls wrote: ↑Wed Feb 02, 2022 3:03 pm Please put us out of our misery.

Okay. (Once Postimage is up again.)

Depends on the file you’re using. If it’s a TZX, the data could be encrypted. Also depends on the selection width, due to alignment. Best to use a RAM dump, rather than a tape file (but some date could very well be compressed as well).

This will probably make it too easy, but I’ve tested your patience long enough.

Hmm. A tough nut to crack, eh?
Well, here’s the opening screen:

Well, I see this one’s proving to be too tough. Here’s another clue, then. The game starts with a fake system tests (including RAM, ROM, character, and sound tests). The “test” takes an annoyingly long time to “complete.” But, if you hit BREAK, the “test” will exit and take you to that 1882 message....

I’m afraid it’s not.

Nope.

Oh, sorry. Got tied up at work.

Here’s a bigger pic:



And a clue: This screen appears when you press the BREAK key.