Upgrading Cyberstorm MK1 from 68040 to 68060

hese

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AmiBayer
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In this blog we upgrade a Cyberstorm MK1 from 68040 to 68060. This conversion is based on the research done by Musicman and Mozart. Cosmos has also described the conversion in his blog. For the conversion you not only need to add the +3.3V voltage supply for the 68060 CPU but also need to do a minor modifications to the Cyberstorm MK1 boards.

Here is a Cyberstorm MK1 68040@40 card I received for the conversion.


First the +3.3V voltage supply was added to the CPU module. The voltage jumper was changed from +5V to +3.3V. Three smd diodes and +3.3V voltage regulator were soldered in place.


The CPU module needed a minor modification. The PALCE16V8H seen on the pictures generates the clock signals for the Cyberstorm. Pin 15 of the PALCE16V8H was isolated from the PCB by cutting the track and a jumper wire from pin 13 (or the resistor next to it) was connected to the cut track. After replacing the old 80MHz oscillator with 50MHz, the CPU module was ready.


The carrier module also needed a small modification. The 74F257A under the Dallas DS1010S chip was modified by lifting the 1st input pin (pin 2, I0A) off the board and connecting it to the ground (pin 8). According to the research the first output (1Y) of 74F257A controls the IPL2 signal of the CPU. With 68040 IPL signals select the buffer size for the CPU on reset. Instead with 68060 the IPL2 controls the CPU's extra write hold mode. No other changes were needed for the carrier module, except installing the BootStrap ROM.


The BootStrap ROM was installed onto the carrier board and activated by switching the Diagnostic ROM jumper to enabled position. The jumper settings for the motherboard were left to the same settings as what they were for the Cyberstorm MK1 68040.


Works fine with the 68060. A nice hack and for a relatively small amount of effort.
 
Good work sir and nice guide!

Thanks for sharing!
 
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