Zwölf now at 160% overclocked, running cool and stable.
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Zwölf is currently being expanded to version 0.2. Version 0.1 was a simple thing that did not have many obstacles that would not allow a higher clock frequency. Now I'm running the little old processor at 8 MHz (Vcc = Vdd = 5V). That's 160% of the specified maximum clock frequency and 450% of my old Elf. It's still running cool and stable. Not even passive cooling is needed. I guess, the next try will be with 9 MHz. Version 0.3 is going to be all aboutmy DIY MMU and slightly expanding the RAM. That's why my first mass storage device is included in this version. I'm going to use a Compact Flash memory card as SSD. Let's hope that it can keep up with a 40 years older processor on steroids. In the long run sooner or later some I/O device must come along that can't keep up with the bus timing at that speed, so I probably will have to throw in wait states into the I/O bus cycles anyway. And if not, I can still squeeze a few more kilobytes per second over the bus by using DMA. Coolest thing of all: The processor does not stop processing instructions for DMA. The program keeps running while we load more data over the bus than it could shovel in a program loop.
I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.
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Zwölf is currently being expanded to version 0.2. Version 0.1 was a simple thing that did not have many obstacles that would not allow a higher clock frequency. Now I'm running the little old processor at 8 MHz (Vcc = Vdd = 5V). That's 160% of the specified maximum clock frequency and 450% of my old Elf. It's still running cool and stable. Not even passive cooling is needed. I guess, the next try will be with 9 MHz. Version 0.3 is going to be all aboutmy DIY MMU and slightly expanding the RAM. That's why my first mass storage device is included in this version. I'm going to use a Compact Flash memory card as SSD. Let's hope that it can keep up with a 40 years older processor on steroids. In the long run sooner or later some I/O device must come along that can't keep up with the bus timing at that speed, so I probably will have to throw in wait states into the I/O bus cycles anyway. And if not, I can still squeeze a few more kilobytes per second over the bus by using DMA. Coolest thing of all: The processor does not stop processing instructions for DMA. The program keeps running while we load more data over the bus than it could shovel in a program loop.
I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.
Do you have any documentation that can help one to re-create your work, and create a clone of the Zwölf to play with?
“Real stupidity beats artificial intelligence every time.” ― Terry Pratchett, Hogfather
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Do you have any documentation that can help one to re-create your work, and create a clone of the Zwölf to play with?
“Real stupidity beats artificial intelligence every time.” ― Terry Pratchett, Hogfather
You can have the schematics and my assembly code for version 0.1. You can easily replicate it on a breadboard and I can point you in the right directions to find useful tools like an assembler and an emulator. Zwölf 0.1 is very bare bones, so that the emulator can still be reconfigured to the few changes to the old Elf. That is really helpful to get you started. Unfortunately the emulator will become useless once I get more of the Zwölfy features working, but I'm already in contact with the author who wants to make the emulator more versatile anyway. Still, the processor is very different from the other 8 bit processors of the time and the emulator will probably be a great help to get you more familiar with it. Later, we will be on our own. Zwöf is a departure from the old Elf concept and therefore most old software and tools will not be very helpful anymore. We are mostly on our own, but that's part of the fun.
I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.
