Switch off the memory or Slow down to Zorro2 speeds

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  • Amiga model:
  • 68060 CPU @ 66Mhz
  • RAM Configuration: 2mb Chip, Apollo 4060 has 128mb, ZZ9000 has 256mb
  • Kickstart, AmigaOS Versions: Both 3.2.1
  • ZZ9000 Firmware version: 1.12.1
  • ZZ9000 Driver version: 1.12.1
  • Monitor model: BenQ
  • Other Zorro cards: X-Surf-100

Hey Guys… i did a much larger reply of my issue here - Zz9900 Guru RTG only - #18 by IvanEBC - but for now i have two simple questions,

Can the ZZ9000 be slowed down to Z2 speeds in my Amiga 4000 (Same as the X-Surf-100 has a jumper and that card also has issues running at Z3 speeds)
Is there a way to tell the card to NOT use the 256mb onboard memory, with maybe a program to run that reboots and “activates” the memory… till power down?

Thank you.

You can just use the Zorro 2 firmware. It will both slow down the card a bit and disable the memory. Also, the memory expansion in the Z3 mode is normally only active after the first reboot. Moreover, there is a Z3 “nofast” firmware version that does not have the extra RAM enabled.

After some testing last year? with Thor and MuLibs, there is good evidence to disable any and all caching with the 68040/68060 and Zorro II 16-bit FastRAM. This is with any 040/060 accelerator in any Amiga host. The quad-longword read/write behavior is standard for these CPUs with Copyback or Writethrough enabled, and the access overhead penalty (to load the data - before the CPU can continue to pull/push register data against the RAM) is a sizable negative penalty in most cases. We have also seen times when the bus hung in the machine from the access overload.

There is even some reasonable argument to disabling the 68040/68060 data cache for the slower Zorro III memory, which is, on average, about 2x the speed of Zorro II RAM when benchmarks are run against it (sequential access). As this RAM gets used nearly last (priority-wise, it’s before Z2 16-bit Fast, but after 32-bit Accelerator and Mobo Ramsey RAM). It, too, can become a bottleneck for the quad-longword 040/060 data cache-burst behavior when heavy access is being done.