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Tube❄️Time

the next step is to add some program memory. it is all 16 bit, so i am using two 8 bit flash memory chips.

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Tube❄️Time

i guess i should write a program. there is an assembler that supports this architecture (john.ccac.rwth-aachen.de:8000/) but i'll get that working later. for now i will just write it in machine code.

 00 JMP@ 1 - 10011000 00000001 = 9801
 01 data .9 - 00000000 00001001 = 0009
 02 0000
 03 0000
 04 0000
 05 0000
 06 0000
 07 0000
 08 0000
 09 SFLG 11   - 0011 1011 10000000 = 3B80
 0A CFLG 11   - 0011 1011 00000000 = 3B00
 0B JMP 09    - 00011000 00001001 = 1809
Tube❄️Time

and we have a blinking LED! this is being driven from one of the 4 flag outputs on the CPU.

Tube❄️Time

the bus timing looks like this. the top trace is the clock, then there is NADS, IDS (input data strobe), and finally the F11 output (which is driving the LED). i cheated and slowed the clock down for the video so you could see it blink.

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