ROM card read logic board - March 2, 2018 | Details

Update May 5, 2018 - IO's failed audition as K.I.T.T from Knight Rider :-) But not bad for just four leds.

Just having some fun with the instruction cards

The ROM instruction board all finished and tested. Now need to wire up more cards.

Update May 1, 2018 - All of the logic is wired and the board tests OK after finding one shorted wire.

Update April 30, 2018 - Here is the progress today. The first image shows the power wiring.

This next image shows how the first two 4 input nand gates are wired to the address buss.

This shows the unit being tested. the simulated address switches are set for address 0001 and a rom instruction card with the value of 0111 is inserted into the second slot. The output leds indicate 0111. So far, so good :-)

Update April 29, 2018 - I have set up the logic gates and ready to do some serious wiring. The four gates on the lower left is the address input from the PC. The 16 Nands at the top decodes the address and selects the required instruction to be read. The four gates on the right side is the instruction output to be sent to the CU.

Update April 17, 2018 - After the usual delays I am getting back to wiring up the logic gates and get back on track with the Brain Warp instructions.

Starting to layout the construction and wiring for the logic board that will read the program ROM cards. Just like all other wiring on IO, this will be a large board...

The ROM back plane will mount above the logic circuits...

Discussions

Dylan Brophy wrote 05/03/2018 at 01:40

This is beautiful :D

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Dr. Cockroach wrote 05/03/2018 at 09:31

Thanks :-D The Control Unit is next and that's my big mental block...

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Joseph Primmer wrote 05/03/2018 at 00:23

Very cool! Coming up with small 16 instruction programs sounds like a fun challenge!

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Dr. Cockroach wrote 05/03/2018 at 00:27

Thanks, Makes the 1k challenge look easy ;-) 16 nibbles is not a lot to work with but still useful as a test bed.

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Morning.Star wrote 05/02/2018 at 23:02

Its been a privilege to watch it come together patiently day by day. Still never ceases to amaze me :-)

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Dr. Cockroach wrote 05/03/2018 at 00:28

Its been a privilege to be here and get to know you all :-)

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Martian wrote 05/01/2018 at 20:47

Nice looking work there, as always, I'm impressed.

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Dr. Cockroach wrote 05/01/2018 at 21:23

Thanks Martian, cardboard is never safe around me ;-) I'll post the final assy photo this evening :-)

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Dr. Cockroach wrote 03/02/2018 at 18:32

Keeping in mind that the Brainwarp instructions are based on Brainf*uck and as such there are only eight instructions. So as a test bed that gives me up to a 16 instruction long program to learn with and that is plenty for BW/BF :-)

At least for now ;-)
and only looking at numeric output ;-)

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David H Haffner Sr wrote 03/02/2018 at 15:41

How many bytes does each ROM slot hold?

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Dr. Cockroach wrote 03/02/2018 at 16:53

Each slot is one nibble ( 4 bits ) for one instruction so the whole board is 16 nibbles or 16 instructions :-) Way under the 1kb challenge Lol As IO is just a learning / testing platform, I am doing things on a very small scale as far as memory is concerned :-) IO2 might be a 8 bit system ans will be able to do more...

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David H Haffner Sr wrote 03/02/2018 at 18:01

That's still two characters, think long and hard about what prophetic message you'd want to display :)

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ROM card read logic board - March 2, 2018

Edge Card Connector Construction

A possible output device for IO

Discussions

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