Spectrum Computing

Can you post clear screenshots of the games overlayed in the images? They were driving me mad.

Were the bent pins on the ULA or the socket? How were they not making a connection? the pins to the socket or the socket to the board?

20% for code seems right to me. You can load .SNA or .TAP files into an image viewer and get an idea of what's code and what's graphics and data. I used Irfanview to generate these images and added my own guesses about what was data and code. Irfanview lets you import any file as raw data so I set i...

This sounds like the exact same issue I had when I built up a new 3b PCB. I never figured out the problem. There's a thread here https://spectrumcomputing.co.uk/forums/viewtopic.php?t=9628 ignore the first few posts about voltages. I'd be interested if you have the same problem with the CPU clock be...

Cheez26 wrote: ↑Fri May 10, 2024 12:02 pm I would love to get into N-GO for higher-end Speccy games since I've been having no luck with getting the OG into the US so far. I hope I can hook it up with RCA/AV cables at least.

The N-GO has the same video out as a Next, so HDMI and RGB/VGA.

These are mine, Black one is a Harlequin 128K rev 2D which I finished building last weekend. Worked first time, well, once I put the ROM in the correct way
Orange is a Harlequin 48K and white is a Next N-GO.

I think it's because those files are just the functions to draw vectors and output to the screen. Currently, because you have the output.txt first that gets compiled to the first address you org'd at and that clears the screen to black and then returns. You need some code to call those functions in ...

It's a macro, from this file https://github.com/breakintoprogram/lib ... macros.z80

I had two games with my speccy. Mikrogen Space Zombies and I forget the other. Space Zombies didn't even work correctly, the ship would move left by itself randomly.

Congratulations Tom.
I'm looking forward to seeing how you and dr beep got your code size so low.

That may be some kind of Newton Raphson approximation I guess? I've not seen that before and some info about it would be good, to see where the worst case approximations occur. EDIT: Probably a Taylor Series approx instead? Probably needs an else though maybe largest + (smallest>>1) - (smallest>>3)...

A hacky way of getting this distance between two 2d points is this determine largest and smallest values from x,y length = largest + (smallest>>1) gives a worst case 12% error if smallest >= (largest>>3) then length = largest + (smallest>>1) - (largest>>3) gives worst case ~6% error but mostly <2%

Thanks Dr Beep, I'll send it through tonight.

Yeah, should be element = (element >> 1) ^ mask; I guess their typewriters didn't have the xor symbol

I've also realised there's more than the three pages I originally photocopied in the full article.

ParadigmShifter wrote: ↑Sat Mar 30, 2024 9:05 am Yeah. Spin always hangs after recording a GIF so consider yourself lucky

I only remembered to whack up the emulator speed to 500% after a bit... BASIC sucks etc.

I love the ones that look like liquid falling down the screen.

I've had this tatty old photocopy of an old Dr Dobbs article for decades which had a really nice way of doing digital dissolves. I found an online copy of it here https://archive.org/details/1986-11-dr-dobbs-journal/page/48/mode/2up It's the Galois LFSR which is on the wikipedia page in the WOS thre...

I'm no expert, but just looking at the pictures of the board on Bytedelight and the Github page above, it looks like the Byte delight has composite out and a video out while the github one has just video out and a kempston joystick port (from reading the features) I'm going to build a 128K from Byte...

As ParadigmShifter said, you're jumping too far ahead if the first key isn't pressed. I think you would find it easier if you moved the three parts of your code into seperate functions. Like below. Then when you add IncreaseY and DecreaseY it will be simple to understand the flow of your code. ; ; R...

I tend to use 24576/$6000. If you aren't using rom routines or anything that needs the sysvars I guess you could use that memory for buffers once the game has loaded.

It looks like a stack crash, some code got caught in an infinite loop and is PUSHing the same six bytes onto the stack over and over.

It's here on ebay, If it's not in the database might be worth buying. https://www.ebay.co.uk/itm/175767531437?itmmeta=01HQ8FVF6AM35HGTRJZ5MTS7Y5&hash=item28ec8fafad:g:GnAAAOSwHNpkDOrc&itmprp=enc%3AAQAIAAAA4PuO1E95ylXW9mUtzE2QsCkiq4JZHIcXzAjDUcT9lFf7l4%2FlsfXDMVGKQaACfa0kjSLxaxiYIBoOLoWOu0D%2...

Charts for the same month from Your Sinclair, lookslike it might be Rally Driver

ULA A14-15 are the same as the Z80, ~0v

ULA A0-A6 are ~3.6v

Thanks for the checklist. Checked all those voltages and currents and they match. 0v was about 0.2v but that's probably fine. Without the Z80 and ULA, I measured the V on the A0-A15 and D0-D7. A lines were all 0v on the Z80 and ~3.6v on the ULA. All the D lines were 4.9v. The KB lines on the ULA wer...

If none of this finds the problem, with ULA, Z80 and TR3 still removed, power up the board and measure the voltages at all three of the transistors terminals, ULA pin 32 and Z80 pin 6, Then, switch to the 200mA current range on your multimeter. Connect it between the Z80 pin 6 and the transistor em...