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MULTITECH pictures[url]http://velesoft.speccy.cz/data-gear.htm[/url]
... , this DMA demo use 3T read + 1T write = 4T for one ... 2T read mem + 1T write to port #FE work too, but ULA draw ... see each transfer byte. 1T read is untested.....[/QUOTE]
ULA is too slow for writing value to port #FE ... -
Input/Output on Edge ConnectorI would like to sense a pulse on the data bus via the edge connector, i.e. on or off. How do you decide what port it is on? I would also like to send…
... the entire port address - for instance the Spectrum's ULA only ... (so the ULA responds to every single even numbered port address). This ... means the port you use ... high again).
To read a pulse, you will need ... -
Input/Output on Edge ConnectorI would like to sense a pulse on the data bus via the edge connector, i.e. on or off. How do you decide what port it is on? I would also like to send…
... when a Kempston joystick is read, the z80 performs an ... for the z80 to read at the end of ... your hardware "completely decodes" port address 31. This means it ... to 127 other port address including port 1,2,3, ... even port addresses so that both your hw and the ULA ... -
Look what I got!Look what I just got in the post: [url]http://www.alioth.net/tmp/W5100.jpg[/url] But, please... don't hold your breath :-) Coming to an edge connec…
... has been generated by the ULA or another source (W5100).
ULA doesn't put a byte ... determine if it's a ULA generated INT or CTC generated ... a simple port that is read, and bit 0 could represent ULA and ... -
Rom dumping a Mirage MicrodriverI need to dump the rom of my Mirage Microdriver for Zub and don't know what to do...any help?
... paging and I/O to port $0038 does too, probably because ... with no ROM to read from, every read would result in 0x00 ... use some unknown custom chippery (ULA/PAL/GAL etc.) it may ... -
Detecting a Kempton joystick...I've been playing with the idea in the games I'm currently developing so that once the Kempston joystick has been selected you can hold FIRE down to …
... non-existing IN port, for instance FF, the ULA won't stop ... data bus. Therefore, you'll read a mixture of 0xff (idle ... will only happen when the ULA is reading the screen memory ... generated. The other 40% the ULA is building the border or ... -
How many expansions can a Speccy handle ?How many expansions / interfaces / addons can a Speccy handle ? I'm not thinking about the issue of powering the interfaces through the Speccy's PS…
... that you can use. (The ULA uses the other 32768, as ... exist on the same port as a read-only device, and they ... -
MB02+ software and system developmentsThe following text was (before last modification) first published here: [url]http://www.sintech-shop.com/forum/board.php?boardid=20[/url] As discuss…
... />
[CODE]
;write PORT B(fixed destination
;adress ... /> Since the divIDE data port has 8-bit addressing, wouldn ...
[CODE]
;write PORT B(fixed destination
;adress ... by ULA (contended ports).
For multisector read you ... -
48K games that don't work on a +2Not sure if there is already a thread about this but recently I've noticed some old 48K games will not run on my +2 - even in 48K mode. Examples are…
... see" what the ULA was doing. When port 255 is used ... Some games seem to read or write to random I ... which sets a bit in port $7FFD which disables any ... 3/+2A/B models have port $1FFD which provides extra ... />
14) The Expansion port is different between a 128 ... -
Questions about the Speccy and it's emulationOut of interest, and to raise another interesting discussion, I have some questions about the Spectrum and it's emulation; 1) Is everything known ab…
... port, then it will in practice read the data currently on the ULA ... $FF being read in i.e. when the ULA is idle, but ... get an attribute byte read in, as the ULA works it's ... a port on which no real hardware is attached, it will read ... -
Pussy - on sale againNo, it is nothing sick, it is just: european users can now buy "Pussy-the Titanic love story" on my homepage [url]http://lcd-one.da.ru[/url] again (p…
... has a modified ULA clone which is able to read from both ... one bit in a OUT port (in interrupts). -
Detecting Spectrum modelsIs there any sure-fire way a program can detect the model of machine it's running on (48K, +, 128, +2, +2A, +3, clones) even when running in the 48K …
... it takes some very specific read/writes combined with the timing ... are only 3 types of ULA (48K/128K/+3), frame length ... />
[1] In theory, reading port 0xbffd should split these very ... -
Preliminary MontyHey All... A new 2009 production (port from Atari) of a game called "Preliminary Monty" is out. It is a VERY nice platform game - with a bit "crude…
... must be tested joystick port. All ZX Spectrum ... br />
If joystick port is tested as inactive, you ... /> HALT ;after interrupt ula draw border and on data ... ) ;if you will read joystick via IN A,( ... exist = you must disable joystick port reading
... -
Preliminary MontyHey All... A new 2009 production (port from Atari) of a game called "Preliminary Monty" is out. It is a VERY nice platform game - with a bit "crude…
... must be tested joystick port. All ZX Spectrum ... br />
If joystick port is tested as inactive, you ... /> HALT ;after interrupt ula draw border and on data ... ) ;if you will read joystick via IN A,( ... exist = you must disable joystick port reading
... -
Preliminary MontyHey All... A new 2009 production (port from Atari) of a game called "Preliminary Monty" is out. It is a VERY nice platform game - with a bit "crude…
... must be tested joystick port. All ZX Spectrum ... br />
If joystick port is tested as inactive, you ... /> HALT ;after interrupt ula draw border and on data ... ) ;if you will read joystick via IN A,( ... exist = you must disable joystick port reading
... -
More colours II (Was: Most popular new features?)The suggested 4xCLUT multi-colour solution never took off.
... ;397338]I believe you can read the contents of the new ... a value out and then read it to see if it ... and it looks that reading port 65539 could work as software ... subject from designers of new ula. -
Tutorial - learn machine code in 30mins[B][I]Message from the moderators[/I] - bigjon has requested that readers' attention be drawn to a better version of this tutorial, one which is easi…
... via an i/o port. DI disables maskable interrupts ... spectrum is that the ULA generates an interrupt at ... you are preventing the ULA interrrupt from doing anything. ... EI in order to read the keyboard in the ... principal loop? Does the port number in bc only ... -
Adjusting your code for screen refreshingOk, I'm aware that I should know it already after writing 5 Spectrum games in machine code but interrupts and screen refreshes were always my weaker …
I've read a bit about floating bus ... an unattached port it will read the data present on the ULA bus ... ?
What is unattached port?
I guess scanning ... this port in loop for value FF ... -
RAM PagingCan anyone shed some light as to how RAM paging actually works, at a hardware level (so not POKE xxxxx stuff). I know about CE and OE lines on DRAMs …
... may be part of a ULA or other type of logic ... /> - something to decode the IO port used to program the flip ... an address below 0x4000 is read from/written to. There is ... -
Tricks with IN 31It's generally considered unwise to use a Kempston joystick's fire button to start a game, because the floating bus effect can make arbitrary data ap…
... disconnected, and I read IN 31 while the ULA is still drawing ... interface is connected, and I read IN 31, can I be ... if is connect joystick. On port 31 can be connect also ... classic autodetection of joy port is possible:
- read port 31 after HALT ... -
emulatorsplease help can we see clearly which emulator emaulates which hardware is there any that has a pc function key for the mulitface nmi button and the +…
... 81 had pretty convincing ula interference but now dot ... crawl and ula snow - though these ... please help
the ula+ is only for the ... dma when loading from spectrum port
will symbals be ... compiler does not allow CLEAR, READ and DATA.
Why doesn't my loop work?Can anyone help me understand why my loop doesn't work? Is it to do with how DEC HL affects the flags? [code] ; Read 32k bytes from port 191 as fa…
... =trellis;496206]What's on port 191? Basically just an octal ... you don't want the ULA to interfere in between readings ... row), you could fill a read buffer with INI instructions (and ... execution you'd have 5KB read data + 5KB remainder still filled ...What if the Government backed Sir CliveHere is a question I have always wondered about... What if the Government had backed Sir Clive back in the Eighties... That is, placed his computers …
... like a built in analogue port and a very tinkerer-friendly ... user port - great for teaching electronics in ... study in economical design (read Chris's ULA book, I think Richard ...RGB to VGA convertor for ZX128/+2/+2A/+3David Luftner release source code (VHDL) of SCANDOUBLER for ZX128/ZX128+2/+2A/+3: [url]http://velesoft.speccy.cz/other/scandoubler-for-zx128_fixed_by…
... implemented something that resembles a ULA displaying VGA: it was an ... to write a VGA-capable ULA in one afternoon.
read video and attribute memory (dual ... screen preloaded into the dual port RAM:
[IMG]http ...How the spectrum generates the video from ramHi everyon, I know that most people here allready know this but i think i found out how the spectrum acctually dispalys stuff and why the LD x, (HL)…
The cpu and ula cannot access the display ram ... devices are time sensitive. The ula has to pause the cpu ... . One is to use dual-port RAM. These are ram chips ... as fast and have the ula or display device access the ... the disp device needs to read at the same time as ...Zx Spectrum 48k+ black screenHi A friend of mine gave me his 48k+ and when i tried to turn it on I just get a black screen of the TV. I don't have sound of the console. Where c…
... is the same for the ULA as well.[/QUOTE]
ULA?
[QUOTE=Zetr0;516387 ... /> this would be my first port of call after the Power ... spectrum to know were to read and which values should I ...Is ZX80 really "Z80 only"?The Spectrum has ULA to generate video display. Does the ZX 80 have any kind of processing chips apart from Z80? How is the video display generated o…
... the time it takes to read a character from the display ... output the result to a port you'd be halfway across ... all integrated into a single ULA, which allowed them to sell ...Serial protocol, help!Hi, simply trying to find best way to transfer programs from PC to real ZX Spectrum for testing purposes. Under Windows I tried using Spxfr and it w…
... M (48k clone with russian ULA) and Didaktik Kompakt (similar to ... and small.
Just read documentation from SIF author. SIF ... end is UR-4 - parallel port with 8255 with covox.
128K Contention - How to get it right?With my recent hardware hackery, I've built a 128K (toastrack) clone. I can't quite get the contention right though. What I'm lack is a clear descri…
... checks whether writing to port 0x3ffd activates memory paging ... partial
;; decoding of "port 0x7ffd"[/code]
port checks?[/quote]
< ... known bug in the 128K ULA.
... real value is read from the port on the + ...128K Contention - How to get it right?With my recent hardware hackery, I've built a 128K (toastrack) clone. I can't quite get the contention right though. What I'm lack is a clear descri…
... It checks whether writing to port 0x3ffd activates memory paging. To ... the partial
;; decoding of "port 0x7ffd"[/code][/quote]
ULA.[/quote]
For my ... it important to reproduce the read from 0x[37]ffd behaviour ...
