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A few questions about machine codeOh no... another noob. I'm giving my first steps in assembler (finally, after 20 years stuck in BASIC). I read a SU article explaining that if I wan…
... say it *outputs* address bits in A8-A15 while doing ... this: The lower address byte is always $FE and ... BC register being used as a BYTE COUNT like LDIR ... bit BC register as a byte count (number of repeats ... = Dest Address, BC = Byte count is specifically defined by ... -
Fastest Baud Rate On A Loader ?Following on (sort of!) from the thread about the best loading.... Which game(s) had the fastest (highest baud rate) ? I seem to remember a couple …
... a bit, 8 bits to the byte, load each byte into RAM.
in interpreting whether the time means ... is not seen in the expected time-frame. Parity bits and checksums ... that pretty much all games used some variation of the same ... -
New (easier) speccy games testI've created a new speccy games test: [url]http://www.sometests.com/tests/Gaming/ZXSpectrumGamesTest_EasierVersion_.html[/url] Again it's 20 questi…
... the code to the last byte and they know what ... two games were written in parallel by the same ... sure that they would used the most optimised and the ... least space-consuming routine in a second, if they ... -optimised and worse routines in if it came after ... -
Minigame Compo 2007Hi there, also this year, there'll be a minigame competition, open to all 8-bit computers and consoles. It consists on writing games whose size (…
... most significant bits
;of offset in A, the last bit ... we shift out the whole byte
;
; every ... again for the rest of byte
;
; ... is provided by the first byte of data
; ... ret
data .BYTE 128
data1
[/CODE ... -
help sought with first foray into machine code - pixel scrolldownI have started to code my first machine code program, a simple roadrace game. I've based it around the pixel scrolldown routine in 40 Best Machine Co…
... display file address for first byte in second last pixel row
... display file address for first byte in last pixel row
ld ... ; check if SSS (scanline) bits started at 0 (ie top ... ld l,a ; decrease LLL bits to move to character row ... -
It's alive![url]http://spectrum.alioth.net/doc/index.php/Current_events[/url] It actually works now :-)
... ). The last octet of the IP address could be used as the ... would not be as flexible in the case of a network ... , with a few extra support bits in ROM (to map IP addresses ... -
.Z80 format question for 128KHello!!! I am working on my ZX Life Shield utility to make it compatible with .Z80 snapshots. I have sucessfully coded .Z80 48K snapshots, but for …
[QUOTE=marcoagpinto;275856]How do I know which page is paged in?[/QUOTE]
Look at the bottom 3 bits of the byte at offset 35. (This is where the last value output to port 7ffd is stored, the port which controls paging.) -
In ye olde days of computingI found this page about some of the the history of home-computing. Maybe not complete, but still: [URL]http://www.jaapan.de/jp/homecomputer.php?page=…
... ahead of the 8-bits in terms of technology.[/QUOTE ... to mention the huge improvements in sound. Also:
used to get:
bits.
16 ... like animated dogs (the last refugee of Melinda Gates ... -
'Ocean Re-united', Byte-Back, videos & photos'Ocean Re-united', Byte-Back Longton, Stoke On Trent, 7th March 2009 "One of the most famous software houses of the 80s and early 90s was Manchester…
... />
For the uninitiated, Byte back was a weekend of ... would make an appearance at Byte Back 2009, for a ...
But I digress. Get used to it.
The ... be a word being used later in the day when this ... the ephemera of the last two decades of all ... -
Simple text compressionI just checked one idea about text compression. Do not take it as recomendation but rather as info which can you save some time when you are solving …
... ]
Huffman encoding improves in the "simple" 12 most ... per week - explained" suggestion last week.[/QUOTE]
i could ... most common words as one byte, and you still have ... the algorithm to use m-bits 'nibbles' instead of 4, ... encode the 48 words in 1 byte ? -
third time luckyquick soldering question for you chaps, I have just soldered a jack plug onto the wire for my speakers. I tried about three times before just snippi…
... 'orrible mess in the uni labs. corroded worn out bits.
in a bit of solder did ... last house suffered damp problems and that used to f*** up my bits in ... -
Bit functions speedI just stared nonplussed at the documentation for the bit functions. Apparently, if you're using the accumulator, using AND and OR is faster than se…
... instruction that's rarely used, because in almost all cases, RRA ... and if you're interested in the flag results, the ... you're just wanting the bits moved, RRA is faster ... code just by changing some bits.
Same ... have a faster 1 byte long alternative. -
I am currently playing......Don't know if there's been a thread like this, but I can't find one.... Having seen all the different threads asking people if they've played such a…
... pretty fun and doesn't last too long...
Galerians ... it made me play the last battle from Galerians again at ... monsters though ( I cheated and used a guide to find where ... far, and Fable has some bits in it that are way better ... -
Help fix this keyboard read program?This code runs in an interrupt routine with DI. What would be the simplest way of making it so it doesn't auto repeat a keypress? [code]keys: ld a…
... copy of the state last call and compare ... b, (hl) ; Get last keypress for YUIOP
ld ... />
; B has last key values
; A ... Pressed
; Top 3 bits in both cases are 0
keyYUIOP: .byte $1f ; Assume initial last state was "all keys ... -
Z80 compressorIs there one available? Is it any good? Peeps have been suggesting we should look into this, so here's a new thread! I'd do the compressor on the …
... done by storing 4 fields in a byte and unpacking this (4 ... Sokoban differently sized.
In 1 byte up to 4 positions with ... values = 3 bits, 4th bit used as valuerepeater)
In Stratego (now ... -
Machine Code Routine of the weekHow about a thread that has a routine each week that is in [B]assembly language[/B] and is also described in great detail what the hell is going on …
... with a corresponding reduction in size and increase in speed. Speaking of ...
pop hl ;restore position in the Message and
inc ...
ret ;inc L is used instead of inc HL[/CODE ... c ;for all 8 bits of the byte
.......
ld a ... -
'Hello World' in ASM ?Can someone show how to make the classic 'Hello World' print with ASM code ? I cant figure at this moment how to insert and handle strings with the s…
... actually going on is, the last 768 bytes of ROM, the ... the screen. The less-significant byte is the number of character ... 't want those lower three bits in D any more.
; character's bitmap in ROM crosses a 256-byte boundary.
Spectranet on the BBC!Yay! I'm famous. Or at least my +3 is famous... [url]http://news.bbc.co.uk/1/hi/technology/10364135.stm[/url]
... asm or squeezing every last byte out or whatever, it ... write for $BIGMACHINE. In any case just because someone ... their learning power is used up and they can ...
Just the same in the hardware side. You don ... microcontrollers like the AVR in this) is that they ...+3 assembler questionI was wondering if anyone could give any suggestions as to how to get this bit of code working on the +2A/+3 in 128k mode. It works on the +128k/+2 i…
... = 00010000, so the two relevant bits are set indicating that the ... BASIC ROM 3 is paged in.[/QUOTE]
Do you ... disabled? Are you writing the 'last byte written' values to the appropriate ...designing a computerHi everyone! I am designing a 4 bit computer and i need some advice, is this a good instruction set? [CODE] BINARY OPCODE DESCRIPTION 00000 nop…
... see the data comes down in a byte from memory chip. First ... byte has a four bit instruction. But there is four bits spare ... EITHER the first four bits or the LAST four bits, YOu must not ... select both.
so in ...How to Extract a Font from a Game?I remember it was possible to load/save your own fonts in ArtStudio on my Speccy. I also remember it was possible to loop the loaded block of a game …
... ? Since text was used quite rare in most games it should ... re trying to squeeze every last byte out of a game ... Starglider 2 the custom font used there is only 6 ... Beep and I showed in posts earlier this year you ... much pride you have in yourself as a Coder....< ...Override AUTOLINE start?Hi there, Is there a poke that prevents a BASIC program from auto running, when it was previously saved with the LINE command? Cheers, Steve
... out (not done that in a loooooong time)!
... HL now points at the last byte of the BASIC program ... need to create room in the program area big
byte after program area otherwise). ... quite nicely - I used this a lot back in '85 ;-)Where's it all going?[Rerouted from 'Assembler Intricacies' in Development Forum] [QUOTE=Timmy;506104]I don't think we're in disagreement here. As I've said it's a niche…
... games were knocked out in weeks sometimes. My God ... right in front of us.
Never having used ... would I be correct in assuming that the trade- ... never seen the equivalent in the day (my primary ... discover that every last byte was being used to produce a ...Where's it all going?[Rerouted from 'Assembler Intricacies' in Development Forum] [QUOTE=Timmy;506104]I don't think we're in disagreement here. As I've said it's a niche…
... we have the answer right in front of us.[/QUOTE]Well ... looking, and wouldn't sell in these days? (I have no ... denicened.)
[QUOTE]We used to see it all the ... to discover that every last byte was being used to produce a few ...Calculating the address of a pixel?Hi Folks, Is there an easy/quick way of calculating the memory address of a pixel? So for example, if I wanted to "plot" pixel at screen coordinate…
... such "optimisation" limited machine performance in other tasks.
[ ... six shared bits, as the two high bits of this byte select RAM ... got the last seventh bit we need, as high bits of both ... raster and attribute address lower byte are ...ZX Poly - wow!Hi Folks, Came across the following: [url]http://www.igormaznitsa.com/zxpoly/zxpoly.html[/url] Has anyone else seen this before? I am no hardware…
... byte: amount of lines to skip before following list is used (255 ... (15 bits, top bit is end of list)
1 byte: data ... write
once the last byte is written to the address ...PS2 megathreadRight i was searching for ps2 discussions, couldnt even find the one id previously done about retro collection packs so thought id start a new one :)…
... like Thief on PC? I used to love that game - the ... that because it has stealthy bits in it, and it's designed ... I like them anyway, the last one is the best one ...Copying a SCREEN$ in ZX BASIC in 1 second?!Following on from the revived "[thread=20207]Saving a complete SCREEN$ in BASIC[/thread]" thread (although Arjun really only needed a suitable POKE i…
... workspace, extend VARS up (in effect) by DIMing a string ... be used (see my posting [thread=30618]"storing machine code in ... BASIC"[/thread] from last August).
in 256 byte steps. Using this trick ...
