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New Photos
07/01/2020 at 05:49 • 0 commentsYesterday's soldering attempt ended in failure, but today's efforts are turning out to be quite promising!
Here you can see a bit slice for one register almost completed. It just needs one more connection between the Set and Reset NANDs:
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Abandoning Project In Favour of LISP Machine Design
06/29/2020 at 13:18 • 0 commentsi am most likely going to begin casually constructing a discrete transistor computer of some form this week. i have been planning this since 2013.
i first started getting interested in computers again, at that time, after i got i got very sick in 2013. it seemed like a pretty cool interest area to re-explore while i was having a convalescence.
i originally designed this computer, the RAVEN, following the MENTAL- series of computers, which i thought would be simple in execution. i think it still would be, but, after studying hardware LISP machines, i am going to abandon the original plan i had for the RAVEN, and instead build the MT15 computer that is outlined by 'Deiter' here: http://www.6502.org/users/dieter/mt15a/mt15a_1.htm, because it effectively /IS/ the architecture of a LISP machine.for instance, look at the data path of the mid-to-late 1970s CADR from MIT:
...and compare it to Detier's MT15:
i am planning to take lots of photos and make lots of videos documenting, all of which will go on the fediverse, my blog, and onto my new peertube.
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New Photos
03/26/2020 at 20:44 • 0 commentsI am going to write a more substantive log soon, but here, see my testing of Deiter's MT15 logic gates:
Video of operation: https://impenetrable.fortress.promo/media/8f4289ee07d7cef0ca89c0265f8393fe93f9aa338107f0fb6fd163afc6279ce0.mp4?name=Husky_1585187742736_MOJXH7018J.mp4 -
New Photo: Breadboard Construction
02/09/2019 at 10:15 • 0 commentsI have switched to literal old school breadboard construction because it is very cheap.
The nails and wood are all reused.
I have also ditched SMD transistors and resistors because dead bug construction with them is too difficult.
I attempted using screws, but they were too big.
Almost all the components have been added, except for the 1N4004 power diodes.
This construction took an afternoon with a hammer and punch. First you tap the nails with a punch, and then hammer the nails.
I estimate this project could be assembled by children, with supervision. The children could used pre drilled wood, and be given small screws with washers.
I will solder the components to the nails once they have all been added.
I will post videos of the operation of the flip flop once I have completed the power supply.
I wonder if it's possible to find second hand 1N4148s in large quantities in Australia...
Loads of this project has used waste materials. Also it encourages technological independence. I will potentially rename this computer the 'Walden', after Henry Thoreau, whose philosophy this computer embodies.
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Five Edge Triggered Inputs Photo
09/15/2018 at 13:40 • 0 comments -
Beginning Soldering - 15 Sept '18
09/15/2018 at 04:15 • 0 commentsThe following are my first efforts at making the direct set and clear circuit for the flip flop:
This is a plane-level view of the triggering sub-circuits:
I can prepare a how to guide about how to solder these circuits. It is a little fiddly but not difficult without a magnifying glass, although I would recommend one.
Good eyesight is needed.
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Sticking It Out, Sometimes
09/10/2018 at 11:43 • 0 commentsI have received a bit of doubt over the past few months about my choice of DTL logic style.
Many people seem to predict that I will not be happy with the performance of my circuits.
But I have not seen any explanations yet - I am open to discussion, as always - would anyone like to expain?
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Supplies #2
09/08/2018 at 22:24 • 0 commentsThe parts have arrived! Below is a selection of the parts that are going into the flip flop modules!
4K7 resistors:
15K resistors:
1N4007 diodes:
4000 x 1n4148 diodes:
200 x transistors:
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Supplies #1
09/07/2018 at 09:08 • 0 commentsJust purchased the right exotic transformer (not really), some solder, and a small voltage regulator!
When we come to the core memory there will be some real power needed, but I think this 100VA dual, tapped secondary transformer will be enough for the whole CPU, excluding the core memory.
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Help Needed: Need To Identify Transformer
08/23/2018 at 06:33 • 2 commentsWould anyone be able to help me identify the specifications of this transformer?
From what I can work out, there is ONE primary winding, and perhaps TWO secondary windings?
What I need is some power supply that is capable of producing -15V-0V-+10V.
Can anyone help?