7001446212
Recipes contain bits and pieces of hardware-related knowledge, but these bits feel sparse. I've been wanting to consolidate hardware- related documentation for a while, but always fell at odds with the recipes organisation. We don't have recipes anymore, just a /doc/hw section that contains hardware-related documentation which often translate to precise instructions to run Collapse OS on a specific machine. With this new organisation, I hope to end up with a better, more solid documentation.
66 lines
2.2 KiB
Plaintext
66 lines
2.2 KiB
Plaintext
# RC2014
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The RC2014[1] is a nice and minimal z80 system that has the
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advantage of being available in an assembly kit. Assembling it
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yourself involves quite a bit of soldering due to the bus
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system. However, one very nice upside of that bus system is that
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each component is isolated and simple.
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The machine used in this recipe is the "Classic" RC2014 with an
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8k ROM module , 32k of RAM, a 7.3728Mhz clock and a serial I/O.
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The ROM module being supplied in the assembly kit is an EPROM,
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not EEPROM, so you can't install Collapse OS on it. You'll have
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to supply your own.
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There are many options around to boot arbitrary sources. What
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was used in this recipe was a AT28C64B EEPROM module. I chose it
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because it's compatible with the 8k ROM module which is very
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convenient. If you do the same, however, don't forget to set the
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A14 jumper to high because what is the A14 pin on the AT27 ROM
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module is the WE pin on the AT28! Setting the jumper high will
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keep is disabled.
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The goal is to have the shell running and accessible through the
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Serial I/O.
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You'll need specialized tools to write data to the AT28 EEPROM.
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There seems to be many devices around made to write in flash and
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EEPROM modules. If you don't have any but have a Arduino Uno,
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take a look at doc/hw/arduinouno.
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# Gathering parts
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* A "classic" RC2014 with Serial I/O
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* An AT28C64B and a way to write to it.
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* A FTDI-to-TTL cable to connect to the Serial I/O module
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# Build the binary
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Building the binary is as simple as running "make" in
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/arch/z80/rc2014. This will yield "os.bin" which can then be
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written to EEPROM.
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This build is controlled by the xcomp.fs unit, which loads
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blk/618. That's what you need to modify if you want to customize
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your build.
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# Emulate
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The Collapse OS project includes a RC2014 emulator suitable for
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this image. You can invoke it with "make emul".
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# Running
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Put the AT28 in the ROM module, don't forget to set the A14
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jumper high, then power the thing up. Connect a FTDI-to-TTL
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cable to the Serial I/O module and identify the tty bound to it
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(in my case, "/dev/ttyUSB0"). Then:
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screen /dev/ttyUSB0 115200
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Press the reset button on the RC2014 and the "ok" prompt should
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appear.
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[1]: https://rc2014.co.uk
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