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hhtg1968
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Joined: 25/05/2023
Location: Germany
Posts: 136

Posted: 05:47am 20 May 2024

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GeoffG and MatherP are trendsetters for the world...

https://olimex.wordpress.com/2024/05/15/meet-rvpc-the-world-lowest-cost-open-source-hardware-all-in-one-educational-risc-v-computer-with-vga-and-ps2-keyboard-which-will-be-available-for-diy-soldering-workshop-on-open-fest-in-sofia-this-year/

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 7912

Posted: 06:56am 20 May 2024

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They even based their PCB hardware on my Pico Stick design. ;)

I bet the board won't be 1 euro by the time it gets to the UK...

Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs

matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10287

Posted: 07:03am 20 May 2024

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16K flash and 2k RAM. Very clever to get it working in such a small package but completely useless?

hhtg1968
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Joined: 25/05/2023
Location: Germany
Posts: 136

Posted: 07:44am 20 May 2024

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to matherp:

you are right. for such a small system it would be better to use a vt100 connection instead of using vga.

Martin H.

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Joined: 04/06/2022
Location: Germany
Posts: 1229

Posted: 10:18am 20 May 2024

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16K flash and 2k RAM?
so maybe ther could run something like ZX80 (8K ROM and 1 K Ram, just to have a comparison) on it
But the would have to be recompiled from Z80 to Risc-V
It would probably not be possible to translate the original ZX81 ROM (16k) to 16K Risc-V code

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robert.rozee
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Joined: 31/12/2012
Location: New Zealand
Posts: 2441

Posted: 10:40am 20 May 2024

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the designers must be getting a pretty good deal on their 3x sockets (VGA, PS/2, power) to be able to squeeze within a us$1.09 (1 euro) price limit.

what would a RP2040 chip + 2mb SPI flash + 3v3 regulator cost if purchasing in bulk? us$2? this is essentially all you need to run mmbasic with VGA output and a USB keyboard, and while you'd struggle to get parts kit + PCB below 3-4 dollars, you would get a whole load more bang-for-your-buck in return.

cheers,
rob :-)

robert.rozee
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Joined: 31/12/2012
Location: New Zealand
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Posted: 10:51am 20 May 2024

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Martin H. said 16K flash and 2k RAM?
so maybe the[y] could run something like ZX80 (8K ROM and 1K RAM, just to have a comparison) on it[,] but the would have to be recompiled from Z80 to Risc-V. It would probably not be possible to translate the original ZX81 ROM (16k) to 16K Risc-V code

4k ROM for ZX80, 8k for ZX81; the spectrum had 16k of ROM.

a translation of the ZX80 ROM has (with a 40% size increase) been shoehorned into 8k of flash and run on an atmega8, see:
https://www.breatharian.eu/hw/atx80/index_en.html

cheers,
rob :-)

Martin H.

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Joined: 04/06/2022
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Posts: 1229

Posted: 11:15am 20 May 2024

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robert.rozee said
4k ROM for ZX80, 8k for ZX81; the spectrum had 16k of ROM.

a translation of the ZX80 ROM has (with a 40% size increase) been shoehorned into 8k of flash and run on an atmega8, see:
https://www.breatharian.eu/hw/atx80/index_en.html

cheers,
rob :-)

Thank you Rob, for the correction.
I couldn't do it anyway, since I wrote some Z80 assembler a long time ago, but have no idea about RISK V. And even if one do, what are you supposed to do with a 2KB ZX81? Except to show as technical demo, that it works.

Cheers
Martin

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