-
Loading data from 128 memoryAfter all these years I have come across the LOAD! in 128 basic for storing/restoring data in the 128 memory. How do I go about implementing this in…
... the extra banks as unformatted memory like all the rest ... the entire 128k memory space as linear memory and are able ... spectrum memory, 64k+ can be all uncontended banks followed by contended ... banks. The set of contended banks is ... -
Another "untested" dead spectrum...Hi, I'm looking for some suggestions on a faulty Spectrum I have picked up. I'll need to wait until tomorrow before posting pics, but the screen is …
... even tried to fill the memory.... or maybe it actually filled ... , or.... most probably, a non contended RAM chip which could be ... -
Plea for new hardwareI'm posting this as a poll as I want to judge if I'm a solo loon going on about this, or if people really are interested in either of the following S…
... upper 8K half of the contended RAM then that's a ... have to sacrifice your upper memory to exploit it.
New IF2 Cartridge: Manic MinerI want to release some IF2 cartridges for ZX-Uno. This is the first one. [url]http://zonadepruebas.com/download/file.php?id=2668[/url] I am not gra…
... s 6.75K of video memory, as you're then ... whole of the RAM is contended, so you may need to ... both in the amount of memory it uses as read-only ... efficient in its use of memory for working areas, as it ... = 34K of RAM, excluding video memory, of which 25K needs to ...Profi interface by Velesoft, i do it ;)Under test. [url]https://www.youtube.com/watch?v=SvNmgfBUR6M&feature=youtu.be[/url]
... to bypass the Spectrum's memory contention (part around 3:45 ... contended only first 8kB of ram pages 5 and 7. Other memory ...Spectrum screen layoutSeeing the thread on displacement I was wondering why the spectrum had the stupid screen split into three sections and the addresses for each section…
... amongst other things) reads from memory whilst minimising contention (i.e ... quarter containing the 16K of contended RAM and an upper ... display generation to the refresh memory. Since the display is ... there are plenty of other memory arrangements that would work ...Test screens for ZX PrismNot sure that this is *really* the right section for this request, but it's relating to new hardware I'm developing so let's start it off here - a mo…
... use the standard spectrum screen memory layout. 8 pixels per ... , a 16K chunk of memory containing two screens can be ... used, again with no additional memory reads required. The restriction ... Prism's video memory is dual port, so no more contended video memory :)Banked memory running slower?I've just compiled a TAP which includes bank6, it loads ok, but the routines that are paged in run slightly slower. The Z80 snapshot has no such pro…
... extra code in a different memory bank?
If so ... which memory bank would be best for ... (1,3,5,7) are contended whereas on the +2A/+3 ...Banked memory running slower?I've just compiled a TAP which includes bank6, it loads ok, but the routines that are paged in run slightly slower. The Z80 snapshot has no such pro…
I assume you could do a contended-ness detector fairly easily too in very little memory.Please explain Spectrum FPGA-clones to meI've been using the great ZXDS-emulator on the DS XL so far, which is great. But I kinda missed toying around with hardware. I've tried bidding on a …
... on-chip memory that I was using for non-contended Video RAM ... a 512K Spectrum with no memory contention (similar to a Pentagon ... output works and lack of memory contention, border and multicolour effects ... t work on ZX Prism. Memory contention will be modelled in ...Banked memory running slower?I've just compiled a TAP which includes bank6, it loads ok, but the routines that are paged in run slightly slower. The Z80 snapshot has no such pro…
... you whether the RAM was contended (slowed down) or not.
memory, updating your own counter, and ...Banked memory running slower?I've just compiled a TAP which includes bank6, it loads ok, but the routines that are paged in run slightly slower. The Z80 snapshot has no such pro…
... particular mode has no screen memory available to the z80, so ... , and yes, it's still contended.Interesting Tweet from Rick Dickinson, the Designer of the Speccy.Tweeted on the 15th Jan: "Is it time to crowd fund a real ZX Spectrum?": [url]https://twitter.com/rickdickinson12/status/555836404522303489[/url] […
... the processor speed, increasing the memory (in line with machines like ... do exactly what FusePSP and ZXDS do. Actually, that's slightly ... wrong. ZXDS is the best non-PC ...Understanding contentionI'm trying to understand contention and its implications when some "weird" bus cycles (such as I/O cycles with I/O addresses in the contended memory …
... between $4000 and $7FFF were contended more than once: both in ... resume for two more cycles (memory cycle) or three more cycles ...Grey +2 and +2A differencesWas the grey +2 incompatability of some of the Spectrum games fixed with the +2A -B?<br><br>
... 7, and the default memory arrangement is banks 5-2 ... , 5 & 7 are contended on the 128K and +2 ... 6 & 7 that are contended. Note that in either situation ... 0 and 2 aren't contended and 5 and 7 ... different things into the other memory banks, and play differently ...Peeking the contents on screen? How?You will have to forgive me for growing up on the C64, but I know I can peek the location of a character (1024 is top left from memory) and the peek …
... the screen display around in memory, there aren't any ... refer to this chunk as 'Contended RAM' because it holds the ... you can POKE and PEEK memory without corrupting anything. At startup ... thirds (each 32x8 characters). In memory, first comes the top pixel ...Renegade by ImagineOn the speccy 128/+2 you got ingame music but not on the +2a/b/3 (paging issue?), although all the 128k's had music on the menu page. Was there ev…
I guess with enough effort you could rearrange the paging to use the correct types of contended/uncontended memory for a +2A, but it'd probably be a real ball ache to find every place where the game pages to tweak it.Spectrum +3 blinking yellow/blueI received a +3, which only gives a yellow/blue blinking border during initialization. Pressing BREAK when powering on does not work, neither does a …
... 6 failure, in either contended or uncontended memory (see the disassembly of ...Spectrum +3 blinking yellow/blueI received a +3, which only gives a yellow/blue blinking border during initialization. Pressing BREAK when powering on does not work, neither does a …
... that it is the non-contended DRAM chip that is faulty ... DRAM chip that provides screen memory.
But best wait ...The I register and IM 1Hi al! I've been doing some coding, replacing the BASIC ROM with my own code and upon examination of a few 16Kb cartridges, all the ones I've look…
... it away from the contended area of memory, 0, for instance. So ...No contended memory?Sorry if this is a stupid question. But I'm trying to learn more about the ZX Spectrum. If I had a stock 48k Speccy and I could wave a magic wa…
... the CPU is halted (and memory contended) is during the actual pixel ...Shadow of the Unicorn loader for +2A / +3hi, i have tried to load SotU with the [url="http://www.worldofspectrum.org/infoseekid.cgi?id=0023000"]RAM loader from Fraser Ross[/url], which is l…
OK, I see the difference between this and a 16K Spectrum - on a 16K Speccy the ROM routines run uncontended. In this case the loading routine AND the memory it is loading to are both contended.Let's copy buffers!Figured I'd do some double buffered graphics, so I can render for several frames before displaying stuff. Yes, I mean on a 48k speccy, so no 128k spe…
... always going to run in contended time - just copy 16 bytes ... process everything else in uncontended memory during rest of the time ...P.O.W.As far as I know, a port of P.O.W. (Prisoners of War) from NHK, doesn't exist. [img]https://cld.pt/dl/download/61d19b5e-453b-489c-b17b-d3ed6fccd594/…
... /> For simplicity - with LDI to contended destination you can copy roughly ... more than half of screen memory (3750 bytes). If you copy ...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…
... be useful, to extend available memory, when not writing to screen ... accesses will be be potentially contended.
It can also ...Where does the BASIC program sit 48K Spectrum memory?Hi there First post so be gentle, I've had a spectrum since the 80's and have recently started programming it for fun again. I wrote the followin…
... only read or write that memory for two out of ... code program running from the contended RAM is much more ... your machine code in higher memory on a 48K machine ... has to write to screen memory, it will be slowed ... is, and how much memory it needs for variables to ...bizarre error on a grey ZX Spectrum+2 - the long search for a small problemHi, I got a ZX Spectrum+2 that worked a bit but crashed while loading or running 128k games. I installed a 128k-test-ROM that told me about RAM fa…
... much so fast to the contended video memory. Most games won't ... deliberately kind of 'riding' the memory contention to get its timing ...What are the differences between the +2 and the +2A ?I only acquired a +2 for the first time in my life a few months ago. It works fine. :) I even managed to tracke down nearly all the wargames by the s…
... scree, so is of course, contended. The other set replaced the ... very similar, and hence the memory contention is the same.
memory layout on the existing (incorrect ... thing about which banks are contended and which are uncontended despite ...What are the differences between the +2 and the +2A ?I only acquired a +2 for the first time in my life a few months ago. It works fine. :) I even managed to tracke down nearly all the wargames by the s…
... to have based the 128k memory layout on the existing (incorrect ... thing about which banks are contended and which are uncontended despite ... why the change in the memory contention layout wasn't spotted ...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…
... 1,3,5,7 are contended, on +2a/+3, banks 4 ... ,5,6,7 are contended. So I suppose +2a/+3 ... ram mode, and have more memory available.
@Woody
