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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…
... , I think. Mirroring the second 16K page is easy, as the ... signals, another one to read video and attribute memory (dual ported RAM ... one that fills the video memory with a pattern to show ... -
yeah - unix for zx spectrumI started a new hobby project. An operating system for ZX Spectrum. A unix clone. Talked to my friend about it and he asked me what if after I'm done…
... ate most of perfectly good 16K and was almost not used ... to port Fuse and everyone read it. ;) ;) How much of ROM ... my research) tape files are memory dumps with register state (something ... -
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)…
... wants to read/write some other area than the lower 16K, there ... their contents, all rows of memory must be accessed with a ... -
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…
... helpful, the ULA can only read from RAM so fast and ... related to the short-lived 16K underspectrum is insignificant :p
16K machine, without it there wouldn ... and really should save more memory in the long run than ... -
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…
... helpful, the ULA can only read from RAM so fast[/QUOTE ... in fact you save more memory overall.
[QUOTE=AndyC ... for the Speccy was a 16K machine, without it there wouldn ... the start, memory upgrades began from the start, so 16K was just ... -
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…
... overclocked) and simplified memory contention scheme - afaik all memory was contended, anytime ... . Also 32K (and even 16K) of video memory (even split into several ... you know too if you read my link)
[QUOTE ... -
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…
... the ULA since I proof-read the logic part of the ... .[/QUOTE]
Unlike you i read something else besides ULA info ... screen = more memory used[/QUOTE]
That matters for 16K model only ... , and 16K model was a mistake ... -
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…
... for a screen memory plus an attribute memory that is ... as possible to save memory for 16K
2) to ... size characters
But 16K model was a mistake, ... screen + attr) must be read at almost the same time ... now:
- page mode read possible if you need it ... -
Memory upgrade for ZX Spectrum 16/48This is external memory upgrade for ZX Spectrum models with 16kB ram. Can be connect also to 48kB models, but need remove 8 dram chips (from sockets …
... version that - connected to 16K ZX-bus - will give ... External upgrade to ZX128 compatible memory is enable, but compatibility ... modifications ! Enable ZX128kB compatible memory but videoram switching is impossible ... speed 3.5MHz (as ram 32768-65535 on ZX48).
... -
DivIDE questionsHi All, I'm the proud owner of two DivIDE interfaces, that I have just "inherited" from a friend. One of them is the original one and the other one …
... =kpuchatek;528672]increase ROM to 16K and allow to map it ... and mb02 ram use same memory chip then all roms are ... is same pages used as read only for rom emulation. Divide ... -
Time difference for jumps and calls?Just interested (and possibly trying to distract myself from the more pressing problems in my sprite routine) and willing to risk a potentially daft …
... have not understood what I read about it - I was thinking ... one could page in different memory blocks to the first 256 ... to the 128k spectrums top 16k. -
Question about divide +Hi A friend has sent my a faultly divide + to see if I can repair it. If I use this divide+ with a spectrum 48K (That works perfectly with my stand…
... normal spectrum 48k.
I read the 29F040 flash eprom. The ... /> Jos? Leandro[/QUOTE]
Read this thread:
[url]http ... test also extended memory on DIVIDE PLUS:
ORG 32768
DI ... -
RAND USR that doesn't work in emulators and clonesEons ago, I "discovered" a strange RANDOMIZE USR. This is it: [b]RANDOMIZE USR 46578[/b] Using it on a genuine ZX Spectrum rubber key or Plus model,…
... EPROM that can hold eight 16K images, which I can ... R, and store them into memory. Later, a print routine ... installed in my ZX Spectrum 16K/48K PCB's. Zilog ... but still frequently seen on 16K/48K PCB's.
... Z80 documented" this can be read:
[quote]Matt has ... -
binutils questionSince there's a few people using binutils these days I thought I'd give it a go and see whether it solves my hunt for a replacement assembler/librari…
... which partitions the Spectrum's memory into sections (those familiar with ... gaps, maximising memory use and also honouring the 16K/32K split if ... the source and can maximise memory use - You know the ... . It would be better to read addresses and locations
; ... -
changing extended RAM pages in SpinIs it possible to edit the data in 128k extended RAM pages in Spin? I've tried both the debugger tool and the pokes tool and, although they let me ma…
... ,4,5 ; write data to memory
org ram1:20000 ... 16384-32767 16K address range)
org ram6:32768 ; start assembling ... /> ; RAM page 6 located at 32768
org ram3:49152 ... -
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…
... read from an even port ([i]any[/i] even port, all 32768 ... of them) you read the border in the ... do 32,768 memory writes.
Every time. 32768 of them ... half of them. That's 32768 writes every time.
Dead Spectrum+Hi! Any suggestions where to start finding what's broken: Spectrum+ with issue 6A motherboard and nothing on TV. Top row of the upper memory chips g…
... again on it. If you read +5V now means that there ... components. If you don't read +5V even with the output ... as normal (although with 16K RAM if upper memory was defective). If ... in the contended bank (low 16K RAM) are damaged, and beyond ...Where to start?..Hello, First off, sorry if this is in the wrong and sorry if the questions I'm about to ask have been asked and answered numerous time! Little back…
... that code with "RANDOMIZE USR 32768".
From Basic you ... have an assembly program in memory at the default address (O ... . You are assembling to address 32768. Your assembly source is located ... know where offhand (you must read the manual or enter an ...Dead Spectrum SocietySo I'm getting back into real Sinclair computers rather than emulators. During the summer months I was lucky enough to buy a working ZX81 and was giv…
... You may have a Spectrum (16K/48K/Plus) that displays a ... all screen (including attribute area) memory with value 00100010b (34 decimal ... is not being written (or read) correctly resulting in that ... code is included in a 16K vector initialization sentence). It ...Classics ported or cloned on good ol' SpeccyHi, Spectrumists! I'm a fan of classic arcade games and I would like to know from you what do you think about ports or clones of such games on the S…
... ,#562,#3D00-#3DFF. If CPU read instruction code on this adress ... DIVIDE interface automatically connect external memory in low 16kB. And this ... only supports replacing the first 16K?[/QUOTE]
yes. All ...What paging scheme is the "standard" for 128K models?Sinclair implemented an arrangement so that even numbered pages are non-contended, and odd numbered pages are contended (quoting from memory, haven't…
... common knowledge that the extra memory was inaccessible; it was only ... 's unclear whether the remaining 16K are being used or could ... for POKE's). Take a read at the article I've ...ZX81, AY, samples, SpecAY, AY files, etc.With the appearance of 3 different AY interfaces for the ZX81 in the past 6 months, I wonder... Is it possible to make the ZX81 "speak" or play digi…
... sample to be at address 32768 or higher. I don't ... memory requirement. Assuming most ZX81 users only have a max of 16K ... not familiar with the ZX81 memory map. All I know is ... usual downside is lack of memory, I have managed 12 bit ...Disable interrupts?Well, I've read the bits from the David Webb book about interrupt modes and (vaguely) appreciate the principles behind having a vector table, after r…
... that to one end of memory or the other, as it ... then you want to manage memory in 16K blocks for paging, so ... try and put things at 32768 or 48896 to fit it ...A z88dk + sp1 demo (with source)Since nowadays people are still wondering about how difficult it is to make something in z88dk, I thought I just put a very simple demo to show how e…
... is that it uses more memory (obviously), but I find that ... -app -lsp1 -lmalloc -lim2 -zorg=32768
****************************************/
// C ... uchar backwalls[];
// Memory to define the background.
Maritrini and Cray 5 loading problemsHas anyone else here had issues loading either of these on a 128k? No matter what I try, both these games refuse to load properly. I can get both t…
... no need for a separate memory value.
ld b, a ... ), A
ld hl, 32768
ld de, 49152
ldir ; copiamos 16k desde 32768 hasta 49152 (en la p ... (C), A
ld hl, 32768
ld de, 49152
Manic Miner ZX81Hi Guys, Can anyone explain why [url=http://www.worldofspectrum.org/infoseekid.cgi?id=0017539]Manic Miner ZX81[/url] is not able to reproduce the ex…
... thought a ZX81 (even with 16K RAM) could do this:
16K to the ZX81. The HGR ... complex circuit, capable of reading memory, forming a display, and, no ... their own one. Later I read about the "hi-res" techniques ...Manic Miner ZX81Hi Guys, Can anyone explain why [url=http://www.worldofspectrum.org/infoseekid.cgi?id=0017539]Manic Miner ZX81[/url] is not able to reproduce the ex…
... memory twice for each byte that's being displayed. The first read ... standard RAM pack as the memory is being refreshed at this ... designed so that the additional 16K was added on top of ...3D Deathchase on the Commodore 643D Deathchase has been ported to the C64, at least according to Micro-Mart. According to this week's MM, the port is called Hell Racer, and here's a …
... ways, yet hampered by less memory? Surely if Commodore's ... did the C16 have literally 16k of memory? If so, then surely ... a large percentage of the memory, leaving little space for ... I want to play, read the books I want to ... read, etc. If only I ...ROM switch on NMIHello! Please, help me or point in the right direction. I am building a project for 48k spectrum which must activate its rom (actually static ram) …
... the access it to lower 16K (ROM) AND MREQ is low ... middle or instruction which read something from memory?
Actually, there ...ROM switch on NMIHello! Please, help me or point in the right direction. I am building a project for 48k spectrum which must activate its rom (actually static ram) …
... the access it to lower 16K (ROM) AND MREQ is low ... middle or instruction which read something from memory?
Actually, there ...
