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Search found 130 matches
- Thu May 16, 2024 7:09 am
- Forum: Sinclair Miscellaneous
- Topic: Wednesday 3 am quiz: Software houses by street view building
- Replies: 23
- Views: 425
Re: Wednesday 3 am quiz: Software houses by street view building
Can you post clear screenshots of the games overlayed in the images? They were driving me mad.
- Wed May 15, 2024 8:23 pm
- Forum: Hardware
- Topic: CPU not starting
- Replies: 31
- Views: 595
Re: CPU not starting
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?
- Tue May 14, 2024 8:56 am
- Forum: Programming
- Topic: How much of a 48k game is graphics? How much is code?
- Replies: 42
- Views: 932
Re: How much of a 48k game is graphics? How much is code?
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...
- Mon May 13, 2024 10:49 am
- Forum: Hardware
- Topic: CPU not starting
- Replies: 31
- Views: 595
Re: CPU not starting
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...
- Fri May 10, 2024 8:07 pm
- Forum: Hardware
- Topic: Show off your Speccy hardware setup!
- Replies: 13
- Views: 431
- Fri May 10, 2024 11:19 am
- Forum: Hardware
- Topic: Show off your Speccy hardware setup!
- Replies: 13
- Views: 431
- Tue Apr 30, 2024 3:26 pm
- Forum: Programming
- Topic: problems with sjasm
- Replies: 4
- Views: 332
Re: problems with sjasm
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 ...
- Tue Apr 30, 2024 1:34 pm
- Forum: Programming
- Topic: bug in z80 library routines website code?
- Replies: 2
- Views: 148
Re: bug in z80 library routines website code?
It's a macro, from this file https://github.com/breakintoprogram/lib ... macros.z80
- Mon Apr 08, 2024 1:49 pm
- Forum: Games/Software
- Topic: First tape/games you got with your ZX Spectrum
- Replies: 37
- Views: 903
Re: First tape/games you got with your ZX Spectrum
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.
- Sat Apr 06, 2024 8:56 am
- Forum: Programming
- Topic: Game of Life sizecoding contest
- Replies: 36
- Views: 2558
Re: Game of Life sizecoding contest
Congratulations Tom.
I'm looking forward to seeing how you and dr beep got your code size so low.
I'm looking forward to seeing how you and dr beep got your code size so low.
- Fri Apr 05, 2024 8:14 am
- Forum: Programming
- Topic: Euclidean dist/Sqrt/Multiplication routines 16bit
- Replies: 38
- Views: 1102
Re: Euclidean dist/Sqrt/Multiplication routines 16bit
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)...
- Wed Apr 03, 2024 10:40 pm
- Forum: Programming
- Topic: Euclidean dist/Sqrt/Multiplication routines 16bit
- Replies: 38
- Views: 1102
Re: Euclidean dist/Sqrt/Multiplication routines 16bit
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%
- Wed Apr 03, 2024 5:43 pm
- Forum: Programming
- Topic: Game of Life sizecoding contest
- Replies: 36
- Views: 2558
Re: Game of Life sizecoding contest
Thanks Dr Beep, I'll send it through tonight.
- Wed Apr 03, 2024 5:42 pm
- Forum: Programming
- Topic: Hull-Dobell theorem for procedural generation/screen fades etc.
- Replies: 21
- Views: 810
Re: Hull-Dobell theorem for procedural generation/screen fades etc.
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.
I've also realised there's more than the three pages I originally photocopied in the full article.
- Sat Mar 30, 2024 11:52 am
- Forum: Programming
- Topic: Hull-Dobell theorem for procedural generation/screen fades etc.
- Replies: 21
- Views: 810
Re: Hull-Dobell theorem for procedural generation/screen fades etc.
I love the ones that look like liquid falling down the screen.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.
- Sat Mar 30, 2024 10:14 am
- Forum: Programming
- Topic: Hull-Dobell theorem for procedural generation/screen fades etc.
- Replies: 21
- Views: 810
Re: Hull-Dobell theorem for procedural generation/screen fades etc.
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...
- Mon Mar 25, 2024 9:53 pm
- Forum: Hardware
- Topic: Harlequin - different versions?
- Replies: 5
- Views: 1032
Re: Harlequin - different versions?
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...
- Mon Mar 18, 2024 9:09 am
- Forum: Programming
- Topic: what would this be equivilent to in assembler?
- Replies: 33
- Views: 1088
Re: what would this be equivilent to in assembler?
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...
- Fri Mar 15, 2024 6:32 pm
- Forum: Programming
- Topic: With Machine Code how much memory to leave basic
- Replies: 7
- Views: 627
Re: With Machine Code how much memory to leave basic
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.
- Thu Mar 14, 2024 8:23 am
- Forum: Sinclair Miscellaneous
- Topic: That thing with the blue and magenta ladders (OUT)
- Replies: 39
- Views: 1535
Re: That thing with the blue and magenta ladders (OUT)
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.
- Thu Feb 22, 2024 1:26 pm
- Forum: Games/Software
- Topic: What on earth is Ball Driver?!?
- Replies: 13
- Views: 457
Re: What on earth is Ball Driver?!?
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...
- Thu Feb 22, 2024 1:17 pm
- Forum: Games/Software
- Topic: What on earth is Ball Driver?!?
- Replies: 13
- Views: 457
- Tue Feb 20, 2024 11:18 am
- Forum: Hardware
- Topic: Incorrect voltages on Spectrum 3b
- Replies: 35
- Views: 1252
Re: Incorrect voltages on Spectrum 3b
ULA A14-15 are the same as the Z80, ~0v
ULA A0-A6 are ~3.6v
ULA A0-A6 are ~3.6v
- Tue Feb 20, 2024 10:19 am
- Forum: Hardware
- Topic: Incorrect voltages on Spectrum 3b
- Replies: 35
- Views: 1252
Re: Incorrect voltages on Spectrum 3b
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...
- Mon Feb 19, 2024 9:25 pm
- Forum: Hardware
- Topic: Incorrect voltages on Spectrum 3b
- Replies: 35
- Views: 1252
Re: Incorrect voltages on Spectrum 3b
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...