Spectrum Computing

Yes, everything Sinclair/Amstrad is now owned by Sky UK.

However, as far as I remember, Amstrad released the ROMS to the public domain, a long time ago (early 2000's).
There was a link to some site about it, but I can't find it.

I would start by: - fixing the power supply circuit. - finding a replacement chip or an equivalent circuit, for the one that is missing. - run some form of memory check (cartridge os expansion interface), once the machine boots to the copyright screen. I would avoid messing with memory, to put socke...

... tl;dr: "cp 191" is a bug. you have to mask bits 6 and 7 of keyboard ports, and never assume that values of those bits are somehow known. by the way, even some "official" ZX games had this bug. ... I would say that you should always mask out what you don't need, and in the ca...

Besides from the obvious conjecture that "Z" comes from the Z80 CPU, does anyone know or have an authoritative answer ?

It's very intense in CPU usage (even with only 14 tracks at start). The scroll slows down music even at ZX Evo, I should fix it somehow. You can download the whole repository http://nedoos.ru/svn/ Try scrolling vertically, instead of horizontally. i.e. Change the layout of the channels on screen to...

I noticed it doesn't allow to set a breakpoint below 10AF, which is kind of weird.

EDIT: It seems to accept .z80 drag&dropped into it.

mrcook wrote: ↑Sun Oct 04, 2020 9:04 am ...
you can see the speccy debugging UI here: https://floooh.github.io/tiny8bit/zx-ui.html?type=zx48k

How exactly do we load software into it ?

Drag & drop seems to do something, but all files I have thrown at it, crash the speccy.
The only non obvious part of the UI.

I searched, but didn't find any reference to this here, so here it is.

https://www.bbcelite.com/

In particular the deep dive section is very interesting

Some nice ideas there, but the first post did say that we should be using 1980s technology... The eZ80 was introduced in 2001. EEPROM / flash memory etc. also is relatively new technology. Same with the FPGA with the Next... Mark Quite true, but did that mean, use chips that existed, or technology ...

I was planning to do something like this

I just wish you had a connector compatible with an Interface II cartridge layout
One can always add one.

For me I would like something like: - CPU eZ80 it's an 8 bit CPU fully compatible with Z80, but supports 24 bits addresses (16MB) as a linear memory addressing mode, or the regular 64K mode. It has an extra 8 bit register, for all the known 16 bit register pairs we know from Z80. This would avoid an...

Well, it's not actually doing debouncing, but key repeat management.

If you are reading a key once, every frame, you don't actually need to debounce it, since bouncing takes place in a lot less than 20ms.

My initial development for steel ball , was done using a 48K, Zeus assembler and a DIV MMC, and it works very well, once you get used to it. But it still as a few quirks, namely: - being hard to move code around, i.e. renumbering blocks of lines easily. - requiring to go back to BASIC to save (but w...

A few months back, I found out that a friend of mine in chuckie egg, never jumped to the ladders, because he thought that it didn't work. And I was pretty sure that I did it all the time, so I showed him how to do it. The trick (that I assumed everybody knew) is to jump to the ladder and while "...

I also implemented a larger compatible cartridge NOXROM , that currently is limited to 128K, 256K or 512K FLASH ROM, depending on the model. It works by paging 16K pages into the ROM address space, except that it's not limited to 16K because you can page in whatever page you want. If you follow the ...

Looking at addresses in decimal is a confusing thing. This is one of the problems of ZX Basic, it doesn't support HEX notation or any functions to convert to/from DECimal <-> HexDecimal. So if you are using basic, a table like this might be useful in that specific case. But if you are really serious...

One of the things that I didn't have time to explain in the presentation, is that due to the color for draw effect, each bubble item can't have a distinct pattern, like the original does, since that would require pixel operations. Having distinct patterns, instead of just color changes, is particula...

This excel like sheet, might be more confusing then useful. You should try and and look at addresses as Hex numbers, since they are easier to visualize, because they have a direct easy mapping to bits. Each Hex digit (0 to F) maps directly to 4 bits. What you need to know the memory frame buffer add...

I don't know any, but it might be interesting. I have a friend, that usually pays networked ZX spectrum games on Saturday night usually. But he never streams it, except for the ones playing the games. I have played Extruder and target renegade with him. By the way, is there some form to list games t...

Join meeee! It’s its palette that gives the Spectrum it’s identity. ... I think you actually nailed it, on how to defined the essence or identity of the Spectrum. For me, just needed: - a faster CPU - more memory Bonus features would be something very basic: - be able to scroll/clip the memory buff...

Don't you have a simple microphone ?

If you can listen to the sound, you can save the audio using a mobile phone for example.

I'm lost for words, to even comment this.

I just wish I could have access to my account to fix my threads in WOS to have the image links corrected.
But my account is still locked.

Apparently, they don't even value the content they have in there.

Nice parallax.
Nice Inertia in the movements physics.
Very smooth game [mention]Ast A. Moore[/mention] .

I believe the one you want is this:

https://www.youtube.com/watch?v=FY6UdjkBdLc

Although it is for +2, he explains the problem in the intermittent RAS/CAS problem.

I would also suggest you see the previous one too, if something doesn't make sense.

I believe there is a video in youtube, by a guy named JoulesPerCoulomb, if I remember correctly, that found a timing issue on ZX that looks very similar to this. Should be easy to find. The solution I believe was to replace or add a Capacitor and a resistor, to delay a signal line. Maybe you want to...