-
Zero v0.8Pigs can apparently fly because it's the v0.8 update of Zero that no one asked for but is out for public consumption anyway. Grab it [url="https:/…
... mode (Hexaae).
- Fixed undocumented flag behaviour of LDxR, CPxR, INxR ... sizing issue (rich_chandler).
- Fixed parity flag being incorrectly reset during interrupt ... (woody).
- Fixed IFF2 flag not being set in SZX ... -
Project: M.u.l.e.Wokani came up with a great idea about trying an open-development approach for spectrum games, and I thought why not try with a game I have under dev…
... ). LDI happens to set the parity flag when BC reaches zero so ... loop though that affects that flag.
Edit: Ooops, you ... -
Overflow Flag QuestionHello all, After a long hiatus (lost all code when my MacBook was stolen) i've gone back to the drawing board and am writing a Z80 emulator in REALb…
Figured it out!
It turns out that DAA uses the P/V flag as a parity flag NOT an overflow flag! Stupid Rodeny Zaks - I wish it had been more clear!
MadDoc, -
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
CPI and friends affect the parity flag also based on the value ... . Whilst BC > 0, the parity remains even.
[code ... -
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... me the effect of the parity flag here. My readings so far ... the context of a parity or overflow flag depending on the instruction ... either a P or V flag. Should have noticed something was ... -
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... , decreasing BC and setting a flag when BC = 0, all in ...
;And set/reset the parity flag based on the value of ... -
writing an emulator-newbie needs helpHi, this is my first post here. I decided to write a minimalistic emulator of ZX Spectrum-no emulation of advanced peripherals, no emulation of sound…
... says P/V flag is treated as a parity flag during NEG instruction ... document it's an overflow flag.
Two last questions ... ", just like in case of flag C?
One last thing ... . According to manuals, P/V flag is set if and only ... -
writing an emulator-newbie needs helpHi, this is my first post here. I decided to write a minimalistic emulator of ZX Spectrum-no emulation of advanced peripherals, no emulation of sound…
... by value to which N flag is set after the ... says P/V flag is treated as a parity flag during NEG ... document it's an overflow flag.
...
One last ... to manuals, P/V flag is set if and only ... s treated as an overflow flag (which is consistent with ... -
Tile based graphics and scrolling thingy...Here's my best attempt so far at a tile based rendering and scrolling routine. It draws in 22 8*8 graphics tiles along the top of the screen (junk i…
Tile based graphics and scrolling thingy...Here's my best attempt so far at a tile based rendering and scrolling routine. It draws in 22 8*8 graphics tiles along the top of the screen (junk i…
... loop using LDI effect on parity flag:
[code]
[...]
flag when BC gets down to ...Testing Z80 op codesHappy new year all! I'm currently testing my Z80 emulator (hand written from scratch in C#) and I've possibly now gone insane, testing is taking hug…
... i had was for the parity flag. most other things i had ...Experimenting with turboloadersHello, My first post, having lurked here for a while. I'm a lifelong computer nerd, Spectrum fan since childhood in the eighties, and have recently…
... the flag register
jp po/pe,lp ; 10T Yup, the parity ... me to (ab)use the parity flag in that way; though one ... it) and thus alter the parity? Is there a way of ...The Pros and Cons of "alternative" assembler syntaxContinuing from [URL]http://www.worldofspectrum.org/forums/showpost.php?p=720754&postcount=72[/URL] [QUOTE=u6c87;720754]But that wouldn't change if…
... syntax it's jump if parity flag set.
(Familiar with ...Mastering flagsI'm little lost when different flags are set/reset after logic operations, and what conditions must be met. For example, [code] ld a, MODE…
The parity flag is set when the result has an even number of bits set.
It's always nice to have a mnemonics table at hand for this kind of stuff. For example, http://www.z80.info/z80flag.htm deals specifically with flags.Mastering flagsI'm little lost when different flags are set/reset after logic operations, and what conditions must be met. For example, [code] ld a, MODE…
Remainder (Mod) calculationsI've been figuring out how to calculate remainders after integer division by a constant divisor k (A mod k = A % k). I found that for most small di…
[quote="Paradigm Shifter;982963"]Most division routines end up with the remainder as a side effect so you shouldn't have to do the multiplication to get the remainder if you have to divide first[/quote]
If you calculate division by a constant using ...Correct flag response to BIT n,(HL) etc.When running the test program suggested by Arjun (thanks again), all intructions are passing the flag tests except the BIT n,(HL), BIT n,(IX+dis) and…
... ), all intructions are passing the flag tests except the BIT n ... program expects the PO flag to reflect the parity of A rather ...Outrun vs Chequered FlagIn the latest issue of Retro Gamer its stated that Out Run was the first racer to have undulating hills etc. I reckon Chequered flag was, however cra…
... hills etc. I reckon Chequered flag was, however craply done. Let ...Need help with my P flag!Not sure if I've emulated the P flag correctly when its comes to overflows. Here's what I've done: LD A,123 LD B,16 ADD A,B Twos Complement of 123 …
... I've emulated the P flag correctly when its comes to ... I've done the overflow flag right.
Thanks in ...Tap file creation, parity error.Hi, I didn't know where to post this question so I've put it here :) I'm writing a program to convert an ascii file into a Spectrum .tap file (yes,…
... Soft taputils there is a parity error within the data block ... , the header parity is ok.
None ...Need help with denied Prince ClumsyI'm trying to create a TZX from my original Prince Clumsy tape. (I'm using an old walkman (only tape player in the house!), goldwave and maketzx). T…
... :
Block Size DataCRC Flag Parity PauseAfter
1 19 37DE9A84 ...Parity ErrorsJust checked my entire collection of TZXs (mostly from WoS) for parity errors - found a few things I wanted to share: "Bubble Bobble" Odd one here!…
... TZXs (mostly from WoS) for parity errors - found a few things ... here! The original TZX contains parity errors before the BleepLoad blocks ... /> The original TZX has 2 parity errors - blocks 1 & ... />
The following games have parity errors in at least 1 ...Quick method of fixing TAP parity byte?Quick question: are there any DOS/Win32 utilities (or at least, something in C/++ I could compile in Windows) which fix the broken parity byte of the…
... Windows) which fix the broken parity byte of the blocks in ...Union flag on Sabre Wulf game boxLooking at this pic, I noticed that the Sabre Wulf box has a Union flag style sticker on it: [url]http://www.digitalarcade.co.uk/speccy/DSC05157001.…
Any "Capture The Flag" games?There used to be a really good DOS game called Capture The Flag which featured two teams of players starting in a land area split in two. The object …
... DOS game called Capture The Flag which featured two teams of ... to capture each other's flag, moving players in turn across ...Overflow Flag QuestionHello all, After a long hiatus (lost all code when my MacBook was stolen) i've gone back to the drawing board and am writing a Z80 emulator in REALb…
... a question about the overflow flag.
I am using ... . This means that my overflow flag is being set when it ...Blocks instructions and the N flagJust a curiosity. I noticed the compare and load block instructions act on the N flag; block compare instructions set it, block load instructions re…
... instructions act on the N flag; block compare instructions set it ... decrease instructions alter the N flag in a similar way. I ...Chequered Flag vs Pole Position[CENTER][IMG]http://www.worldofspectrum.org/showscreen.cgi?screen=screens/in-game/c/ChequeredFlag.gif[/IMG][IMG]http://www.worldofspectrum.org/showsc…
... /> My first impressions of Chequered Flag were very good, funny game ... my vote goes to Chequered Flag.Oops, wrong flag!North Korean women's football team have reacted angrily to the South Korean flag being shown by accident on stadium screens during the warm-up. Not …
... angrily to the South Korean flag being shown by accident on ... -to-play-after-south-korea-flag-at-hampden-park/[/url]Chequered Flag / Brum-BrumDuring a recent inconclusive search for a nebulous car racing game I noticed a couple of dubious categorisations. Namely, the venerable Chequered Fla…
... categorisations. Namely, the venerable Chequered Flag, which seems to be the ...
