> Perhaps using one of the 6502 variants that indicate "next instruction" > on a pin is an option? groepaz, I'm only aware of one such variant, and that is the 65C816. Is that what you had in mind? The '816 does wake up in 6502 "Emulation Mode," so perhaps it's suitable for Frank's needs. And as you probably know, it has two outputs (VPA and VPD) which, when both low, reveal that a dummy cycle is in progress. VPA and VPD get updated early in the cycle, same as the address lines. So, it's an early indication... but not quite a *prediction*. Hope this helps, Jeff aka Dr Jefyll :) On 2023-10-13 08:04, groepaz_at_gmx.net wrote: > Am Freitag, 13. Oktober 2023, 13:55:12 CEST schrieb Frank Wolf: >> Yes... this would work for single byte op codes and some stack related >> operations >> >> but not for some indexed operations where such a memory access (it's >> actually >> >> not only dummy reads but also some dummy writes) happens if there's a >> page >> >> boundary crossing. > > mmmh right, you'll need to keep track of the penalty cycles too.... > that makes > it a bit less straightforward. > > Perhaps using one of the 6502 variants that indicate "next instruction" > on a > pin is an option? > > -- > > http://hitmen.eu http://ar.pokefinder.org > http://vice-emu.sourceforge.net http://magicdisk.untergrund.net > > Some people say that I must be a horrible person, but that's not true. > I have > the heart of a small boy --- in a jar on my desk > <Stephen King>Received on 2023-10-15 22:00:03
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