At that moment in time, the "Hobby" computer was cut of the edge technology:
- compatible with both of the major Z80 operating systems of the time: CP/M and ZX Spectrum
- single (256 x 192) and double (512 x 192) screen resolution
- hardware switchable Z80 clock 3.5 MHz (standard) or 7 MHz (double)
- software memory pagination: Z80 can address maximum 64 KB of memory, but this system had a total of 114 KB (64 + 16 KB of RAM and 32 + 2 KB of EPROM)
- first overclock that i knew so far (at that moment the maximum clock frequency for a Z80 microprocessor was 6 MHz, mine was working at 7 MHz)
- first "overburn" on floppy disks that i knew so far (similar with CD overburn but on floppy disks): the standard file system had normally 80 tracks on a floppy, mine had up to 85 tracks.
A BIG "THANK YOU" TO ALL THE PEOPLE WHO HELPED ME TO DESIGN AND IMPLEMENT THE XOR HOBBY COMPUTER PROTOTYPE
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Full of dust
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The power source
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Under the hood
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"Motherboard" detail
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Soldered wire wrapping
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Programming in BASIC
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Still functional after so many years
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CP/M floppy disks still readable
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Normal ZX Spectrum resolution, 256x192
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Double resolution, 512x192, useful for CP/M OS
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On the right, a development board (like an ancient Arduino shield :)
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Filmed in HDTV with Nikon D90 and 18-105mm f/3.5-5.6G ED AF-S VR DX Nikkor Zoom Lens on 18'th of February 2009
3D Printing AVR Arduino Art Audio Automation BeagleBone Bluetooth Cameras Clock Drones Environment Hardware IoT LED Medical Music Radio Raspberry Pi Remote Control Robotics Rockets Satellites Science Security Software Virtual Reality Wearables
Dear George,
This is a great job!
I live in Budapest. In 80's there was also communism in Hungary. There was legal market for ICs in Hungary (for ones which were not on Cocom List). The Z80 family was available at horror price (much more than my pocket money :-) ). I can remember how was I crying when I killed the Z80 in my first computer: Sinclair ZX81. I think you invested all of your pocket money and time into this project when you were 18...
Congrats again!