Author Topic: NMI Questions/Problems  (Read 328 times)

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Offline SOS

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NMI Questions/Problems
« on: 19:15, 03 May 20 »
Hi folks!

I'm playing around with NMI-Interrupts.
For this i patched the Lower-ROM and placed at &66 an
border-flashing-function to see if this is working (the function starts with "DI" and uses only OUT's and no OS-functions).

I'm confused with the results - when i make an Interrupt from external, i have the results:
Successful (border flashing):
- Plain BASIC
- Antiriad
- Zoids
- Endurance

Not successful:
- 1943
- Elevator Action
- Kickstart 2

The "not successful" shows an reaction of the Interrupt but makes different things (like short stopping, screen dizzle, …).
Has someone an Idea?
The NMI goes every time to the Lower-ROM or to the seclected Destination? (LowerROM / RAM)
(can the LowerROM activate from the outside of the CPC?)


Offline andycadley

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Re: NMI Questions/Problems
« Reply #1 on: 19:48, 03 May 20 »
The NMI will hit whatever is currently pages in, so if the Lower ROM is off it will go to whatever is currently in RAM.

Offline SOS

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Re: NMI Questions/Problems
« Reply #2 on: 20:27, 03 May 20 »
thanks, any possibillity to activate the lower-rom from external?
(how handle the Multiface 2 this problem?)

Offline m_dr_m

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Re: NMI Questions/Problems
« Reply #3 on: 03:19, 04 May 20 »
The Multiface II connects its own ROM when emitting the interrupt.
I guess by using both RAMDIS and ROMDIS ([size=78%]http://www.cpcwiki.eu/index.php/Connector:Expansion_port[/size])

Offline GUNHED

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Re: NMI Questions/Problems
« Reply #4 on: 19:51, 04 May 20 »
Actually for NMI practice it's great to use Tot0's PlayCity which provides an very easy to handle NMI.

The Albireo does also provide an NMI, but it's not as easy to handle.
http://futureos.de --> Get the revolutionary FutureOS (Recent update: 2019.08.07)
http://futureos.cpc-live.com/files/LambdaSpeak_RSX_by_TFM.zip --> Get the RSX-ROM for LambdaSpeak :-) (Updated: 2019.08.14)