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[NEW] Speccy for Android ReleasedHello, All! A while ago, I have released the Android version of [i]Speccy[/i], my ZX Spectrum emulator. It emulates Spectrum 16k, 48k, 128k, +2, +2A…
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CHANGES:
* Added accurate R register emulation, many protected boot loaders ... .
* Added more realistic "LD R,A" opcode to the Z80 ... -
ULA snow effectIt's wintertime, you know. [quote="http://ramsoft.bbk.org.omegahg.com/floatingbus.html"]when the I register falls in the range 0x40-0x7F then the UL…
... I can see where the r register only incrementing through the lower ... -
ULA snow effectIt's wintertime, you know. [quote="http://ramsoft.bbk.org.omegahg.com/floatingbus.html"]when the I register falls in the range 0x40-0x7F then the UL…
... can see where the r register only incrementing through the ... offset value in another register, which is then copied ... 4 update B and R
ld r,a ;9 96T ... pattern for the values in R becomes (assuming offset = ... lines except every 3rd : R loops back to char. ... -
ULA snow effectIt's wintertime, you know. [quote="http://ramsoft.bbk.org.omegahg.com/floatingbus.html"]when the I register falls in the range 0x40-0x7F then the UL…
... address
A7-A0 = the R register of the Z80
[/QUOTE ... -
ULA snow effectIt's wintertime, you know. [quote="http://ramsoft.bbk.org.omegahg.com/floatingbus.html"]when the I register falls in the range 0x40-0x7F then the UL…
... address for A15-A7, and R register for A6-A0. That slightly ... contradicts the Ramsoft docs (R for A7-A0 stated there ... -
Help with 1-bit sampled soundHi all, I've been sent over this way from the CPC Wiki forums as you guys may be able to help me more specifically with a programming query. Firstly…
... byte holds 2 x 7-bit values. Bits 3-5 are ... also a check for a high bit being set, which will exit ... it's taking a 7-bit value and outputting 8 values ... than a pre-arranged 1-bit PDM datastream. So I think ... -
Intel x64 vs Zilog Z80Just been having a gander at the x86 CPU Architucture here: [url]http://software.intel.com/sites/default/files/m/d/4/1/d/8/Introduction_to_x64_Assemb…
... /> Page 3 references the RFLAGS register. I find it humbling that ... within this register: CF = Bit 0, PF = Bit 2, ZF = Bit 6, SF = Bit 7 ... -
Does this addressing technique have a name?Hi All, Bit of a weird/unnecessary question, but can anyone help build on my knowledge of asm terminology by telling me what the *second* method of …
... ] extended addressing
r register addressing
[rr] register indirect addressing
[/code ... -
Beautiful codeSome people see beauty or something sublime in maths formulas and equations, can anyone suggest examples of beautiful or sublime programming?
... ; (DE), ending when char has high bit set. Char < 20H is ... -
Games without score/status panelAfter the previous thread discussing decorative borders/status panels, and watching the recent Spectrum Show, I noticed that with the exception of th…
... house etc.). W.A.R. looks a bit of a dog's ... to make the experience a bit more immersive (or whatever).
bit... -
HALT: Why always 4ts?Instruction breakdown of halt is like that: PC 4ts. That means it fetches instruction byte from ram which tooks 4 ts and then does nothing and read…
... .[/QUOTE]
Sounds logical. So R register keeps being updated, too. And ... when HALT is exit-ed, R value may say something about ... -
TV Pal, odd and even framesI have been researching, but haven't found any real interesting information on this subject, so far. What I mean is, since TV PAL signal is interl…
Maybe the count in R register is different after a few cycles after Interrupt, between odd and even pages, since ULA stops the CPU clock in some situations (accessing screen memory is probably one of them), and odd and even lines have different timings. -
Bored of the Rings coded messageI was browsing [url="https://tcrf.net/"]The Cutting Room Floor[/url] recently and stumbled upon the entry for [url="https://tcrf.net/Bored_of_the_Rin…
You may need to know the value of the R register at the time the message was created :-) -
Bored of the Rings coded messageI was browsing [url="https://tcrf.net/"]The Cutting Room Floor[/url] recently and stumbled upon the entry for [url="https://tcrf.net/Bored_of_the_Rin…
... know the value of the R register at the time the message ... the message was "encrypted" using R register, it would be impossible to ... -
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…
... LD I,A and LD R,A, associated with (A15, A14 ... we know that I and R register are both reset to ZERO ... is constantly outputting I and R values on the bus, so ... -
R registerI'm cross-posting this as a spin-off of a [url="http://www.worldofspectrum.org/forums/discussion/52748/zx-spectrum-cartridges/p2"]thread in "Hardware…
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6.1 R register and memory refresh
[ ... issued. The whole IR register is put on the ... the Z80 increases the R register before or after putting ... without a prefix increase R by one[/u]. [ ... LD A,R and LD R,A access the R register after it ... -
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…
... .worldofspectrum.org/forums/discussion/52782/r-register"]this dedicated thread[/url].
R by one[/u]. [b] ... CB, DD, FD prefix, increase R by two, and so do ... . LD A,R and LD R,A access the R register after it is ... -
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…
... address, by controlling I and R register.
P.S ... -
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…
... ]L[/b]" bit is used to LOCK selection register (6 bit flip-flop ... to serially pump/populate selection register with data.
This ... to just load the bank register in one go, by using ... access, or use an extra bit to lock (as is used ... -
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…
... 'm aware there is a bit of optimisation I could have ... ,gen_score_str
; Update score high bit
inc hl
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…
... ,gen_score_str
; Update score high bit
ld a,(hl ...So where is the random number in the Speccy ?So I am messing around with ZX Spectrum Assembler and I want a random number. I looked up previous posts and one of the links said that random number…
... is probably to load the R register or the LSB of FRAMES ...c64 .sid player coming soon to specy 128!!!c64 .sid player coming soon to specy 128!!! the first old version uses only square waves, 4 years ago: https://www.youtube.com/watch?v=6CKt9noxA7s…
... responds as follows:
Bit 0: Paging mode. 0=normal ... mode, ignored.
Bit 2: In normal mode, high bit of ROM selection ... /> ROM 3: 48 BASIC
Bit 3: Disk motor; 1=on ... , 0=off
Bit 4: Printer port strobe.c64 .sid player coming soon to specy 128!!!c64 .sid player coming soon to specy 128!!! the first old version uses only square waves, 4 years ago: https://www.youtube.com/watch?v=6CKt9noxA7s…
... responds as follows:
Bit 0: Paging mode. 0=normal ... mode, ignored.
Bit 2: In normal mode, high bit of ROM selection ... /> ROM 3: 48 BASIC
Bit 3: Disk motor; 1=on ... , 0=off
Bit 4: Printer port strobe.[/quote ...Copying a single character from one place to another?[code] ORG 33000 LD A,8 LD HL,16384 LD BC,256 LD DE, 18432 LOOP: PUSH AF LD A,(HL) LD (DE),A ADD HL, BC POP AF DEC A JR NZ,LOOP REST […
... 16bits and H is the high bit.
If I now INC ...ZX Nuvo 128..Hi There, I have built the ZX Nuvo 128 by Superfo, but it has a problem. The machine is working, but the video signal is completely bonkers. I've …
... the heading `Memory management'). Bit 3 controls the disk motor ... bit should be brought low and then returned to its normally high ...
[quote]Port 1FFD
Bit 0: Paging mode. 0=normal ... , ignored.
Bit 2: In normal mode, high bit of ROM selection ...The I register pointing to $40–$7f causes ULA snow and a crash. Or does it?I have heard it from numerous sources, including a few members of this forum, that 128K/+2 machines crash if the I register points to a range of $40–…
... ISR itself simply reads the R register, places its value into A ... mucks about with the I register but restores it prior to ... just by setting the interrupt register to $40–7f but to ...A snapshot to transfer converterI'm programming a tool that takes an snapshot file and convert it to a tape file that mimics those created with transfers. This is a long term projec…
... .
- Have some doubts about R register. I've got to test ...
