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128K memory bank selection to avoid contention issuesI'm currently developing a game and I'm trying to get my head around the memory contention issues of the various 128K/+2/+2A/+3 spectrum models in or…
... my head around the memory contention issues of the various ... which is in the 16K bank $4000-$7FFF. Hence if ... paged in, so without any bank switching, that is where ... screen. I understand that bank 2 is already resident at ... 2A/+3 load instead into bank 1 or 3?? I ... -
128K Contention - How to get it right?With my recent hardware hackery, I've built a 128K (toastrack) clone. I can't quite get the contention right though. What I'm lack is a clear descri…
... 0x7ffd, 0xbffd and 0x3ffd port contention behaviour.
With ... Can someone describe accurately the contention behaviour for the 128K ports ... 128/+2 have different memory bank models, does not help ... talking about the 128?, bank bit B0 implies odd pages ... -
West Bank XxI released!Hello all of you! It's the first time I write in this forum, so I'll present me: I'm the webmaster of Computer Emuzone, a page dedicated to the span…
... software) of the classic West Bank (Dinamic, published in UK by ... />
Its name is "West Bank XxI". Please check it and ... -
Memory Map/ContentionHi I'm new to speccy coding (well I did some z80 coding a few years back - like 20yrs ago :) ), and I'd like to get back into writing some scrolling…
... a correct map for memory contention?
Address Size Area ... -
I/O contention model questionHi everyone, Sorry for my poor english. Together with a friend we are working on ZX Spectrum 48k implemented in FPGA. We have found bug in the Spect…
... .s faq describing I/O contention.
The 48k ... to lead to the following contention patterns:
High ... /> in 40 - 7F? | Low bit | Contention pattern
------------+---------+-------------------
No | Reset ... -
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... .org/infoseek.cgi?regexp=^West+Bank$&pub=^Dinamic+Software$& ... ;loadpics=on] West Bank[/url]
Good game ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
... playing a bit with memory contention and floating bus stuff in ... sense it starts applying the contention a few cycles earlier, namely ... -
Places to Picnic this bank holidayMy wife has suggested we go on a picnic family picnic this weekend. We live in South Harrow in NW London and want to get out of town for the day. A…
... very bad idea on a Bank Holiday weekend, can anyone suggest ... -
West Bank (missing artist)[URL="http://www.worldofspectrum.org/infoseekid.cgi?id=0005664&loadpics=3"]West Bank[/URL] Snatcho lower left. ( [URL="http://www.worldofspectrum.o…
... =0005664&loadpics=3"]West Bank[/URL]
Snatcho lower ... -
Memory mapping: Pentagon compatibility?I'm writing something that will rely heavily on the Spectrum's ability to switch screen buffers in hardware (port 0x7FFD). The original Spectrum 128K…
... only one 16K bank pageable) and the contention timings on port 0x7FFD ... -
Spring Bank Holiday Sale at Flashbackgames.co.ukJust wanted to let you know that FlashbackGames is having a bit of a sale over the next week. So if it is a rainy bank holiday (most likely) then wh…
... if it is a rainy bank holiday (most likely) then why ... -
West Bank for iOS by original authorAny iPod/iPad owning fans of [URL="http://www.worldofspectrum.org/infoseekid.cgi?id=0005664"]West Bank[/URL] on the Speccy might want to check out th…
... /infoseekid.cgi?id=0005664"]West Bank[/URL] on the Speccy might ... .com/gb/app/zx-west-bank/id451796188?mt=8[/url]
BIT b,(ii+n) contentionThe documentation says that BIT b,(ii+n) has this contention pattern: pc+1:4,pc+2:3,pc+3:3,pc+3:1 x 2,ii+n:3,ii+n:1 See [url]http://scratchpad.wiki…
... b,(ii+n) has this contention pattern:
pc+1 ... Tstate.
So the contention pattern should be:
maximum addressable RAM for a Z80 using bank switching?What is the maximum addressable RAM for a Z80 using bank switching? The Enterprise64 home computer could address up to 4MB, is this the limit for a …
... RAM for a Z80 using bank switching?
The Enterprise64 ... a Z80?
A bank switching scheme allows the memory ...LOAD "" CODE in machine code/store 128 bank dataHow do you LOAD "" CODE from machine code? I have written the following MC routine that fits into a REM statement in a basic program. I want to cal…
... worth of 128 code in bank 6?
[CODE]ld ... screen
;LOAD 128 bank 6 code
;LOAD ...Issue 1 16K RAM bankFolks, I recently had a chance to fix a couple of Issue 1 boards, and learned the hard way that the chips in the 16K RAM bank have a different place…
... chips in the 16K RAM bank have a different placement when ...Is bank 7 usable at all?Can you assemble stuff and page bank 7 in and out? I've encountered nothing but problems so far, where does it page to? 49152?
Can you assemble stuff and page bank 7 in and out?
I've encountered nothing but problems so far, where does it page to?
49152?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 …
I'm trying to understand contention and its implications when some ... both memory and I/O contention. Memory contention causes T1 to be ... ?
Also: memory contention makes T1 to be enlarged ... for instance, to avoid memory contention) that begins at the ...How did bank switching work on the 128K Spectrums?I'm new to Z80 and ZX Spectrum. So I was wondering how the 128+ models managed to work with more than 64K of memory? I'm somewhat familiar with h…
... 'm somewhat familiar with how bank switching works (I believe the ...Question of contentionI'm not desperate to go digging through technical descriptions in depth, but one thing bugs me about the Speccy's video contention model - and that's…
... about the Speccy's video contention model - and that's the ... /> And then there's the contention pattern where the memory is ... 16, so that means the contention pattern covers a run of ...West Bank only running with Kempston Joystick on ZX SpinI can get West Bank [url="http://www.worldofspectrum.org/infoseekid.cgi?id=0005664"]worldofspectrum.org/infoseekid.cgi?id=0005664[/url] only to run w…
I can get West Bank [url="http://www.worldofspectrum.org/ ...Memory Contention: A Hypothetical Fix?I have just had this crazy thought: If one were to wire an additional memory chip, say a 6264 8Kx8 SRAM, in parallel with the main memory so that it …
... reduce the effect of memory contention considerably. Possibly with the addition ...Writing own emulator: Contention questionsHi! (I don't know if this message should be here or in Hardware) I'm trying to write my own emulator just for the sake of it, and I'm having pr…
... having problems understanding the memory contention in 48k, in instructions like ... is being used there for contention.
Thanks ...Blizzard PassThis is one for testing an emulator since it works with not many. Theres a notice on the inlay. Select 128 basic then enter out 32765,23 then J"".
... instruction locks the ram/rom bank configuration and is not implemented ... ram bank 7 which is contended so maybe its a memory contention ...128k Screen Flipping - Sample Code PleaseI know this has been covered before, but I cannot find out code to do the following: On a 128k Spectrum tell the speccy to display from address 4915…
... Bank 0 | Bank 1 | Bank 2 | Bank 3 | Bank 4 | Bank 5 | Bank 6 | Bank ... | | screen |
C000h +--------+--------+--------+--------+--------+--------+--------+--------+
| Bank 2 | Any one of these ... also causes contention, although the ...Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
... pointed out, the IO contention and Memory contention differ. So the ... contended according to the memory contention pattern and the other ... there is a contented memory bank paged in? How could ... slightly different test for memory contention in this case anyway, ...Compatible SpectrumsFollowing some recent coding exploits I've been thinking about compatibility of various models of ZX Spectrum. Yes, it's a common question on the for…
... all... due to the memory contention issues. The +2a/+3 had ... also the issue of different contention timings to the "original" models ... can't change the hardware contention, surely.
... all that goodies as RAM bank switching, AY sound, RS232, ...
