Floating bus is the name given ... computer nothing will drive the bus. So the value on ... apart from +2A, +2B and +3 Amstrad models) there are separator ... resistors between the data bus for [the lower RAM ... ] and the CPU side data bus [CPU, ROM, upper RAM, ...

... uses the floating bus to synchronise the screen, causing +2A / +3 to lock ... up. Pentagon also does not exhibit floating bus behaviour ... -States. It checks for the floating bus and if it does not ...

... and +3 models return bits 0-6 of the floating bus if unused ... all models to use a floating bus for frame sync without hardware ...

... a solution to add the floating bus port to ffh port.
3 do have floating bus port, but doesn't ...

... "it does not have a floating bus" description that has been used ... about the +2A, +2B and +3.

What they should ...

... programmer relying on this for floating bus effects would still have to ... specifically test for +2A/+3 hardware before using this trick ...

... was originally looking at the +3 .dsk version which unfortunately ... mechanism in the form of floating bus reads. This improves the ... minimal (e.g. zero 3 bytes starting from #9B47 in ... on busier levels like Lv.3 *insert appropriately suggestive onomatopoeia as ...

... times walks by +/- 2 or 3 microseconds per frame. Ojito, that ... I solved in PI 2/3 leaving the CPU-0 to ... the moment, nuclei 2 and 3 leave them sleeping the sleep ... of the Z80, contained memory, floating bus, accurately drawn both the edge ...

... on a +2A/+3) get the result of the "floating bus". This will ...

... on a +2A/+3) get the result of the "floating bus". This will ... ]

In Timex machines floating bus is 0, if I remember ...

... on a +2A/+3) get the result of the "floating bus". This will ... ]

In Timex machines floating bus is 0, if I remember ... the issue with the +2A/+3, as IIRC they don't ...

... the issue with the +2A/+3, as IIRC they don't ... ]

Sorry, if +2A/+3 don't have I/O ... by I/O) but exhibit floating bus, then this idea is useless ...

... 128K/+2 from +2a/+2b/+3 is to use the fact ... Spectrums do not have the floating bus ("port #FF"). Therefore, you can ... if this computer has the floating bus (assumes that screen is filled ... can assume that pages 0..3 are always uncontended and pages ...

... more arbitrary values, or has Woody based this on something?
floating-bus-1.png?dl=1[/img ...

... represent bytes read off the floating bus port, #0FFD in this case ... anything similar to floating bus functionality on the +2A/+3 models, I believe ...

Thank you, @richl! You have just successfully beta tested the first Spectrum game to use the floating bus for synchronization on a +2A/+3. I’ll post more when I get home.

... doesn’t emulate the floating bus on a +2A/+3 properly (or at ...

I suppose, it's need to test floating bus with extended memory paging modes of +2A/+3, for full information.

... for floating bus testing in extended paging mode of +2A/+3? Maybe floating bus reading ...

... .[/quote]
Right. Using the floating bus as a way of syncing ... /> So, neither the quirky +2A/+3 bus behavior, nor the “standard” 48K ...

... you're experimenting with the floating bus sync now.[/quote]
I ... , so got interested in the floating bus trick. Then it kind of ... now we’re on page 3. ;)

... influence of memory operations to floating bus probably concerns "slow" memory pages ... ,5,6,7 for +2A/+3 (for 128/+2 they are ...

... influence of memory operations to floating bus probably concerns "slow" memory pages ... ,5,6,7 for +2A/+3 (for 128/+2 they are ... 1,3,5,7).[/quote]

[quote="colonel32;921789"]Is it coming from WZ/MEMPTR, like bits 3 and 5 of F?[/quote]

I don't think so, because WZ/MEMPTR is a peculiarity of z80, but floating bus is a peculiarity of ULA .

... quite exact emulation of the floating bus (but also related to the ... (to actually see it).
3. Put a breakpoint on #9C89 ...

... quite exact emulation of the floating bus (but also related to the ... (to actually see it).
3. Put a breakpoint on #9C89 ...

... optimizations
—Now uses the floating bus for synchronization. [b]The first ... use this method on +2A/+3 machines![/b]

Instructions ...

... -people-with-a-2a-3"]solved the floating bus mystery[/url] on the ... +2A/+3, many previously incompatible games ... also trivial to modify the 3.5 mm jack to accept ...

... tackled down the floating bus nitty-gritty on the +2A/+3, I have ...

... tackled down the floating bus nitty-gritty on the +2A/+3, I have ... of fb on the +2A/+3, and wrote that test primarily ...