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I feel they could have done this.After reading the ZX Spectrum ULA, I learned about how the ULA detects if the Z80 if going to access memory in the next cycle and stops it if the ULA…
... already in there. In addition memory is pretty expensive to implement ... ULA isn't generating the screen picture. The contention circuit is ... of being able to read screen memory. Even trivial things like saving ... -
Removal of "reset on break" protection (old basic program)Hi, Long time lurker, here! This is hopefully quite simple but there's an old basic game in the I'd like to bring up to date / take a look at …
... TO 5: BEEP .05,X: NEXT X
9725 REM IF ... 9775
9751 REM the next line is modified to have the ... -
Peeking the contents on screen? How?You will have to forgive me for growing up on the C64, but I know I can peek the location of a character (1024 is top left from memory) and the peek …
... are far faster than SCREEN$.
SCREEN$ is slow because it ... of pixel data from the screen, then run through the character ... fetching a byte from the screen memory. -
RFC: 64 column font codeIn BASIC, type CLEAR 49999 then import the code at 50000. Then type RANDOMIZE USR 50000. This will create a new channel and attach stream #4 to it. A…
Well, this was dumb.
[quote="JamesD;834985"]...
[spoiler][code]
lda #32 ;point to next line
tay
...
lda #64 ;point to next line
tay
etc...
[/code][/spoiler]
[/quote] -
An interface for real-time image enhancement?Far away from a hardware development guy, I was wondering if it would possible for an interface (such as Spectra) to include real-time frame processi…
... to read out the Spectrum screen memory thru the port, as its ... does just that, reads the screen contents from the expansion port ... -
Spectrum +3 blinking yellow/blueI received a +3, which only gives a yellow/blue blinking border during initialization. Pressing BREAK when powering on does not work, neither does a …
... /> My guess is that that screen is saying that one of ... the DRAM chip that provides screen memory.
But best wait ... -
RFC: 64 column font codeIn BASIC, type CLEAR 49999 then import the code at 50000. Then type RANDOMIZE USR 50000. This will create a new channel and attach stream #4 to it. A…
... fit are printed on the next line. Once in a while one ... version in z88dk adds colour, line spacing, windows and functions to ... -
ZX Spectrum Sprite chipHi everyone. As I said some time ago, I wanted to make a 'virtual' Sprite chip for the ZX spectrum, on my ZEsarUX emulator. The idea is to make so…
... each processor), and treated the screen memory as 64-bits and the ... -
DVD title sequenceHello I'm not sure if this is the best place for this - but let's see how we go. I run a little DVD making company here in Cardiff, and we are …
... -thirds of the loading screen is done like Manic ... the last 2¾K of screen memory. You can hear one ... set of 8 screen lines repeating 8 times, ... in early to finish the screen.
That way ... characters appear down the screen in white on black ... -
How do you do masked sprites with attributes?Is this possible and how would you do it? :) Thanks :)
... background (the value already in screen memory). The mask is a bitmap ... write it back to the screen.
To set the attributes ... (D800 for the 128k shadow screen) in 24 rows of 32 ... -
Compression comparisonsI did some comparisons of different compression methods. To make this relevant to zx spectrum, I first gathered a corpus of relevant data: 6660 .TAP …
... unpack all the data to screen memory, then copy the sprites you ... -
Can anyone show a slight diagram of how pokes work in a jet set willy game for example?I know its kind of something to do with machine code and Memory addresses etc but would be nice to see a youtube video or some drawings etc ? .Many t…
... ;point to the start of screen memory
LD B,8 ... the pattern to display into memory at HL
... top left of the screen. Once you've figured ... it elsewhere on the screen etc. Because it writes ... to screen RAM you'll be ... -
Machine Code for Beginners - error?Dear all, I've picked rather old book called Machine Code for Beginners by Usborne.1983 There's an example inside which claims to print a messa…
... " "because of the way the screen memory is organised". What a joke ... into display memory will make the char appear on the screen.
SkoolKit 5.1SkoolKit 5.1 has been released. SkoolKit is a set of command line utilities for disassembling Spectrum software, into ASM format or into a bunch o…
... seems to decide that the screen memory is a data block. I ... 'code data' permanently in the screen memory. I think I'm aware ...How R@RE was the 16k Speccy?I'm curious about the ratio of 16K to 48K models sold - the 16K seems to be a pretty rare beast these days. All the people I knew who had 16K Speccys…
The 16K ZX81 had a lot more usable space in it, of course. Apparently an attempt to convert 3D Monster Maze for the 16K Speccy had to be abandoned because the 7K of screen memory left insufficient space for the code.Emulator developmentHi, Could anyone explain or direct to a link that explains in not to technical terms how an emulator is developed. It has always blown my mind eve…
... there's a write to screen memory (from 16384 to 23295 in ...Publisher files opinion neededIf you look at dev.worldofspectrum.org/infoseek/publishers/view/sinclairresearchltd You'll see at the bottom the additional publisher files. These a…
... side then goes to the next line...
a pic can ...Publisher files opinion neededIf you look at dev.worldofspectrum.org/infoseek/publishers/view/sinclairresearchltd You'll see at the bottom the additional publisher files. These a…
[quote="ASH-II;854254"]A minor niggle when I looked at the ultimate poster (thumbnails) they didn't list evenly , for some reason it sticks one at the right side then goes to the next line...
[/quote]
FixedHarlequin 128k??Hi peeps... I've seen that you can do a 128k version of the Harlequin board. Is it just the standard board with different chips or is it a dif…
... which addresses it reads for screen memory. It'd be fairly easy ...Leading Zeroes on a Score in BASICI'm trying to print the score with leading zeroes such that it's always 6 characters wide, i.e.: 000010, 000150, 006100 etc. I quickly knocked thi…
... the case of a FOR...NEXT control variable, use "FOR ... a=1 TO 1: NEXT a" or similar.) I ... test loop, so any "next line" overhead is kept to a ... doesn't affect the line search times for the ... slight overhead of the FOR...NEXT statements themselves which enclose ...Help needed with MIA software with custom (?) loaderHi, I've got into my hands recently a bunch of Polish educational software which are unknown MIA on WOS. I believe they are protected with some…
... RST 20 ; NEXT-CHAR, Advance CH-ADD along the line. (ROM ... zero' before proceeding.(ROM)
LINE-USE: 0x5B90 CP 01 ; ... the location before the 'next' line's first character in DE ... .(ROM)
NEXT-LINE: 0x5BA2 LD (5C55),HL ; ...Spectrum +2A floating bus portHi As I discovered in the past, Spectrum +2A (and probably +3) do have floating bus port. But it is not shown on all unused ports, only on some po…
... of attribute values in the screen memory (no synchronizing with the beginning ... /end of the screen etc) in order to work ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... [/img]
Vertical YELLOW line, represents affected simulation position.
Memory (RED line), MUST be issued into ROM ... ), so that no actual RAM memory is affected by this write ...Speeding up programs by hacking the SysVarsPositively pleased to properly discover this area of the forum! I have a couple of recent tricks that might be of interest - they're probably old hat…
... PROG search; eg.:
FN, NEXT, GO TO, GO SUB, MERGE ... colon or ENTER. Checking 1BD1 NEXT-LINE and 1BEE CHECK-END indicates ... than one statment on a line, as colon is checked after ...Speeding up programs by hacking the SysVarsPositively pleased to properly discover this area of the forum! I have a couple of recent tricks that might be of interest - they're probably old hat…
... colon or ENTER. Checking 1BD1 NEXT-LINE and 1BEE CHECK-END indicates ... than one statment on a line, as colon is checked after ... in a sole multi-statement line. But you're right, not ... the overhead of the next statement in a line processing. I might ...Where does the BASIC program sit 48K Spectrum memory?Hi there First post so be gentle, I've had a spectrum since the 80's and have recently started programming it for fun again. I wrote the followin…
... program sits just after the screen memory and the system variables, and ... growing until it fills the memory.
If you ... generally mess around with the memory from 40000 upwards without damaging ... are the pixels of the screen. 22528-23295 are the ...Where does the BASIC program sit 48K Spectrum memory?Hi there First post so be gentle, I've had a spectrum since the 80's and have recently started programming it for fun again. I wrote the followin…
... other words, replacing the screen from something in storage:< ... it'll copy the screen memory to address 58368 (near ... the top of memory, leaving just enough room ... you'll notice the memory addresses are encoded as ... 228 to copy another screen at 51456. Just ...Where does the BASIC program sit 48K Spectrum memory?Hi there First post so be gentle, I've had a spectrum since the 80's and have recently started programming it for fun again. I wrote the followin…
... other words, replacing the screen from something in storage:< ... it'll copy the screen memory to address 58368 (near ... the top of memory, leaving just enough room ... you'll notice the memory addresses are encoded as ... 228 to copy another screen at 51456. Just ...Where does the BASIC program sit 48K Spectrum memory?Hi there First post so be gentle, I've had a spectrum since the 80's and have recently started programming it for fun again. I wrote the followin…
... machine-code instruction for copying memory - you will hopefully be ... machine code which do screen -> memory and memory -> screen. Thank you very ... Where do I change the memory destination? Which one of the ... values contains the target memory location ?
