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| 68040 mhz |
Posted by: zigzagjoe on 2026-02-09 06:21:01
I did know about the 68060, but I'm unsure about the 040. The 060 was introduced with a nominal speed of 50 MHz up to 75 MHz, while the 040 remained stuck at 40 MHz, even in the L88 mask, despite several reductions in silicon or die size over the years. I'm not sure if this was due to its internal complexity, since it was a CICS chip and the 060 was a RISC-CISC chip. Increasing the voltage on the 040 would achieve 50 MHz without damaging it or causing electromigration? I don't know what more you wish me to add as I laid out the salient points in earlier posts. Work-in-progress accelerator, E42K, half speed system bus. 5V. I was feeding in the base clock to the system PLL via an external signal generator but that was just to make my life easier as I tweaked.
It's important to remember that the datasheet and chip markings represent what Motorola was willing to specify the behavior of the chip at. Outside of there timings are not guaranteed, but there is nothing precluding the chip attempting to operate according to whatever clocks it receives. This is the basis of overclocking. 50mhz BCLK (100mhz PCLK) is out of spec on 68040, yes, but in application any of the later mask chips should achieve that without particular care. Several period accelerators shipped as "clock doublers" in that you installed them in a 25mhz bus system to run CPU at 50mhz. No reliability data exists but no reason to believe it would cause long term issues either.
In Macintosh applications the extended system bus usually is the limiting factor for higher clocks combined with the 040's small buffer mode. On (amiga) accelerators the small high-speed bus allows higher CPU clocks. |
Posted by: konrad on 2026-02-12 01:51:21
Search in internet https://github.com/Kochise/m68140 |
Posted by: Bolle on 2026-02-12 05:01:57
What kind of bullshit is that? |
Posted by: finkmac on 2026-02-12 06:00:07
What kind of bullshit is that? llm slop or a child's imagination. call it |
Posted by: Bolle on 2026-02-12 06:04:36
Yeah, I would've deemed it fanfic at best 🙄 |
Posted by: luRaichu on 2026-02-12 07:58:30
rockin' my 68140 with WD-40 power! |
Posted by: Melkhior on 2026-02-12 08:05:24
Spectacularly ignorant BS at that. The MC68120 actually exists, and it's not exactly a high-performance successor to the MC680x0:
The MC68120/MC68121 Intelligent Peripheral Controller (lPC) is a general purpose, mask programmable peripheral controller. The IPC provides the interface between an M68000 or M6800 Family microprocessor and the final peripheral devices through a system bus and control lines. 1984 databook, so at least as old as that. |
Posted by: defor on 2026-02-12 13:45:07
Closing this thread.
Conversation is going in circles, and the overall conversation is rection unrelated to the main focus of this site (vintage MACINTOSH computers and related ephemera)
Continued questioning of clear evidence and speculation in the face of proof isn't beneficial to anyone. |
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