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Mark1960 · 22nd Nov 2022, 8:54 am

I think the zx80 and zx81 had resistors between the ram and the z80 so they could force NOPs into the z80 while the video circuit reads the ram. These would probably prevent any serious bus contention.

22nd Nov 2022, 8:54 am	#21
Mark1960 Octode Join Date: Mar 2020 Location: Kitchener, Ontario, Canada Posts: 1,298	Re: 6502 NOP generator I think the zx80 and zx81 had resistors between the ram and the z80 so they could force NOPs into the z80 while the video circuit reads the ram. These would probably prevent any serious bus contention.