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Re: CPU's and boards for hobbyists?

Cross-posted to 3 groups.

Followups directed to: comp.sys.misc, comp.arch.embedded

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>>>>> Wilf  <wilfredk@live.com> writes:

	[Cross-posting to news:comp.sys.misc, and dropping
	news:comp.os.cpm (in favor of the former) from Followup-To:.]

 > There is this one recently produced in Australia.  The target market
 > is I think people who had one in the 80's.
 > http://www.microbeetechnology.com.au/

	The point is that as a "remake", such a computer is not to be
	expected to be cheap.  And, indeed, it isn't.

	For a "non-kit", one-board (cheap) computer, I'd probably check
	Raspberry Pi or the Gooseberry board.  Both are ought to be
	rather fully-featured, with over than 29000 software packages
	readily available [1].

[1] http://www.debian.org/

 > The Maximite was another on based on a PIC device.  Quite different
 > but did have BASIC.  http://geoffg.net/maximite.html

	I've mentioned DuinoMite (a derivative system from a different
	vendor) already in this thread.

	Unfortunately, the designer behind Maximite, and also the author
	of the MMBasic firmware bundled, has regretted his earlier
	choice to release MMBasic as free software, as the design has
	readily spawned a number of derivatives (including DuinoMite),
	whose respective authors not necessarily credited him, or at
	times provided inferior versions of the software, allegedly
	harming his reputation.

	... A feature of the design is the use of the SPI interface to
	drive a VGA interface, which seems like a clever one (even if it
	wasn't the first time SPI was used for such a trick.)  However,
	it made me wonder on what CPU frequency is used?  (I see the
	crystal, but I presume the chip has an internal frequency
	multiplier.)

	Also, I see that while the ATmega8-family MCU's are able to
	drive SPI at half the core frequency, it's possible to get the
	system's clock output at the CLKO pin.  I wonder if it may make
	sense to drive a parallel-to-serial chip (such as, e. g.,
	74HC165) to achieve the 20 MHz pixel clock for such an
	improvised VGA output?  (I. e., instead of using the
	SPI-internal shift register.)

-- 
FSF associate member #7257

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Re: CPU's and boards for hobbyists? Ivan Shmakov <oneingray@gmail.com> - 2012-11-22 23:59 +0700

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