How hardware accelerators deals with $0/$01

From: Jesus Cea <*jcea_at_jcea.es*> Date: Wed, 18 Oct 2017 05:45:13 +0200 Message-Id: <2DE6D84D-5A31-404A-9A8B-ED0C06BDC342@jcea.es> · jcea_at_jcea.es

I am new in the mailing list. I beg your pardon if my question is off topic.

Thinking about how turbo master or supercpu acceleration Cartridges work I suppose that they disable the internal 6510 via the DMA signal in the Cartridge port. From that point any processing is done in the external CPU, the internal 6510 is idle/disabled.

I wonder how the acceleration card can access the hardware ports mapped in $0/$1 to control memory banking, the tape interface, etc.

The only option I see is that the 6510 is running a tight loop reading commands to read/write those addresses and that the card is releasing the DMA briefly when the fast CPU access those location for the 6510 to continue execution and simulate the access, but this seems complicated and fragile.

What am I missing?

Thanks in advance for your time and attention.

Enviado desde mi iPhone

       Message was sent through the cbm-hackers mailing list