One of the Best CPU ever made: MC680xx

RE: One of the Best CPU ever made: MC680xx

DAB — Mon, 18 Dec 2023 20:25:15 GMT

I agree, the design of the chip was very cool at the time.

RE: One of the Best CPU ever made: MC680xx

dougw — Mon, 18 Dec 2023 20:18:34 GMT

I think most would agree it was the best CPU architecture at the time. I am still a fan and I still have my Amiga. Unfortunately IBM didn't end up using it in the PC, the world would be different if they had.

RE: One of the Best CPU ever made: MC680xx

shabaz — Mon, 18 Dec 2023 17:23:27 GMT

It was an awesome chip : ) We studied it too, as part of a computer architecture curriculum.

After uni, I tried making a handheld 68k computer, using the neat "Dragonball VZ" chip (which was a 68k core). I got to the stage of creating a board test program, with a memory monitor to test the RAM/ROM and started writing a first application (which was merely writing its output to a memory buffer pretending to be a screen). This board was used just to test the power supplies, so it's not populated. The 68k chip was at bottom-right of the board, and the other main chips are Flash and SRAM.

Everything was an uphill struggle to do solo, there were no ESP32 etc for WiFi, so an external WiFi card was supposed to plug onto the PCMCIA connector in the photo below. The LCD screen was surplus from mobile phones and was only going to be 320x240 or something, but driving that was a pain too (there was no controller, so a CPLD was going to be used with a separate SRAM chip, to offload video refresh from the 68k).

I really liked the Freescale/Motorola chips because they had excellent bootloaders, so you could get the initial code for the 68K running over UART, and then push into Flash from there. No fancy JTAG/programmers needed!

RE: One of the Best CPU ever made: MC680xx

Jan Cumps — Mon, 18 Dec 2023 14:45:37 GMT

In my IT studies, learning assembler for the 68 was on the curriculum. And an exam exercise.

RE: One of the Best CPU ever made: MC680xx

scottiebabe — Mon, 18 Dec 2023 14:31:42 GMT

The Coldfire! [emoticon:34a31d54900f4d07b1322e895f940968] [emoticon:d3f592d49e434d7fb67e973881d4c367]

No need to load/store on registers, you get indirect addressing.