- 05/06/2018 at 22:42 • 12 comments
04/11/2018 at 19:30 •
Finally have been able to get IO to print out its first word. The home made opto-couplers had a little light leakage issue near the leds but sealed that end off with black silicone and now all of the circuit is working as desired :-)
04/09/2018 at 23:25 •
I have decided that even though the relay will work as isolation for the printer signals, I see that it would take a lot of time to perfect and build the number that I need. Sooooo, I am rolling my own opto-couplers. @Morning.Star provided the seed to go this way and it is so simple. The CdS cells are from old style night lights found in area thrift stores and the Leds I already have so take a look at the construction images and smile a little. BTW I have seen this method else where on the internet and it works quite well. With no light the cell has a resistance of 15k ohms and full led light it goes down to 400 ohms. IO and the printer work well with it.
The SCR? and 1meg resistor might find a use later on.
Good swing in resistance.
Here is a very short video of two couplers connected between IO and the printer. No timing or signal level issues :-)
03/21/2018 at 10:58 •
Here is the second version of the Uglytech relay. I will try this for signal isolation to the typewriter/printer. Still needs work but getting better at this...
This video shows that the relay does work with both IO and the printer Note the screw and nut added to adjust gap.
03/02/2018 at 17:11 •
Found this Smith Corona Typewriter for $8 and it works fine. No, the Hello World is not from IO... I might be able to patch IO into the keyboard electronics so please pray for me on this one :-)
The keys press a small rubber? coated finger across the meshed contacts so I think that the contact is acting like a capacitor. Going to begin mapping out the matrix...
So far so good. The contacts are simple make and break. Makes the use with IO a little easier :-
So here it is March 4, 2018 and I have cobbled up a plug in adapter to where the keyboard ribbon cable connects to the main board. Take a look at the progression and either shake your head or chuckle a little but the connection is rock solid.
At least this way I can restore the typewriter back to the way it used to be later :-)
Here is how the connector has mapped out.
03/02/2018 at 13:03 •
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...
02/20/2018 at 23:17 •
I have streamlined the construction of my 5 contact edge connector to where I can produce the number that I need for Brainwarp. What follows is a pictorial step by step for making a cardboard edge connector. One thing to note is that the contact center to center is 3/4 inch. Materials are cardboard, brass paper fasteners and hot melt glue.
As of February 22, 2018 I now have 10 connectors just about finished.
This is the Mock-up of the Brainwarp ROM motherboard. Still needs six more connectors.
02/15/2018 at 23:19 •
Edge connectors made with cardboard ? Yup
This is a side project for IOs Brainwarp. The magnetic cards are not making very good consistent contact over time so I am looking into rolling my own edge connectors using my usual cardboard and fasteners.
What can I say,. It's pure Uglytech :-D But it works..... Muahahahaha
February 16, 2018
Well, it works with the addressed test board so I think that this is a go :-)
02/10/2018 at 23:21 •
Testing the logic for a diode ROM to be used on the Brainwarp entry panel. So far so good as it is working as expected. This test panel uses 2 bit addressing to select between 4 memory addresses with 4 bits each.
01/31/2018 at 02:04 •
I have added a very basic speed control to the master clock circuit.