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Amiga computer related discussion => Amiga community support ideas => Topic started by: aquapuls on April 28, 2013, 04:34:44 PM

Title: Micronik Z2i(6860) rev.5.42 and Impact A2000-HC+8 Series II GURU ROM
Post by: aquapuls on April 28, 2013, 04:34:44 PM

Configuration:
A1200
Blizzard PPC
Micronik Z2i(6860) rev.5.42
Impact A2000-HC+8 Series II GURU ROM 6.13
SCSI HDD on board Impact

Speed ​​SCSI HDD, installed on the Impact only 1,200,000 BYTES / SEC
Why such a low rate?
Any ideas?

Title: Re: Micronik Z2i(6860) rev.5.42 and Impact A2000-HC+8 Series II GURU ROM
Post by: Zetr0 on April 28, 2013, 07:27:03 PM

@aquapuls

Sadly the HC8 range of cards struggle with an 060 at the best of times.

The Micronnic Busboard (Z2i) provides a Z2 backplane for the A1200 - the theoretical throughput of this 16bit bus is aproximately 3.56MB per second, however there will be buffering and bus-controlling over heads going on and this will reduce that speed.

However I suspect that your low speed is due to the HC8 no longer able to DMA for the CPU (since it only has 16bit memory) - instead having to buffer from a 16bit FIFO to 32bit RAM - the latter of which the CPU has to do.  I suspect there is a little play in the numbers for sure (1.2MB per sec is low) but I doubt its possible to get it much past 1.6MB a second with your current set up I am sorry to say.

Title: Re: Micronik Z2i(6860) rev.5.42 and Impact A2000-HC+8 Series II GURU ROM
Post by: aquapuls on April 28, 2013, 09:07:55 PM

@Zetr0

Thanks for the reply.