Speeding up a Microbotics 1230XA accelerator for the Amiga


I had been experiencing an overall poor performance of my Amiga 1200 (classic desktop configuration) for a while. I use AmigaOS 3.9 plus all Boing Bags (official & unofficial) and all sort of patches like FBlit, Ftext, Iconbefast … so I started wondering how could I increase the performance of my system.

Poor performances mainly show up in the way of extremely slow icon redrawing under Workbench so the first thing I did was to slow down color depth to 64 colors. Newicons redrawing speed improved a bit, but I thought that something more could be done so I launched sysinfo benchmarks from within AmigaDOS.

Sysinfo was showing 6500 dhrystones for my Microbotics 1230XA accelerator, which was very far from the nearly 8000 that could be achieved according to some reviews I found on Aminet so … what was going on?

I launched the setXA utility, a program intented to change accelerator card configuration but I realized the settings where not stored correctly in the accelerator’s EEPROM memory if launched from within AmigaOS 3.9.

I decided to try booting the Amiga with AmigaOS 3.1 install floppy and switched to the drivers disk for the Microbotics accelerator card, ran setXA from it and this time … big surprise !! settings were changed and stored correctly. I set RAM amount to 128 Mb (which was already OK) and RAM speed to 60 ns (it was set to a conservative 80 ns previously) and 4 cycles. Speed improvement was about 1000 dhrystones, reaching 7500 total. So the trick for this card is finding a very fast 72 PIN SIMM (EDO or FPM) : the faster the memory the faster will work the accelerator with suitable settings through setXA application.

24-02-12 Update :

But the best part was yet to come : as suggested in this review (see paragraph entitled “Review Addendum”), I decided to underclock the card to 33 Mhz by means of the above mentioned setXA utility. When you do so, RAM cycles are automatically configured to 3 and sysinfo throws an incredible figure of about 8300 dhrystones!

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