#garfield Logs

Apr 01 2021

12:05 AM aandrew: rue_mohr: I don't think VGA -> HDMI will work as three ADCs except as the most basic of capture interfaces
12:13 AM aandrew: you're probably easier to just use two comparators for each of RGB, but you'll need counters driven off the pixel clock to know when to capture everything
12:17 AM rue_mohr: oh fpga->lvds has been done a lot
12:18 AM rue_mohr: https://hackaday.com/2012/10/03/lvds-on-an-fpga-could-make-it-possible-to-reuse-laptops-lcds-and-the-like/
12:57 AM rue_bed: I wonder what a laptop usually looks like between the gpu and the lvds
12:58 AM rue_bed: if its parallel->lvds or ... or many other things
08:35 AM aandrew: Rue_bed: distraction time: https://laughtonelectronics.com/Arcana/One-bit%20computer/One-bit%20computer.html
08:59 AM aandrew: Weird, that guy lives not far from me
11:29 AM polprog: rue_bed: make prototypes quicker * :P
11:29 AM polprog: i cant wait to test my wire wrapper
12:27 PM polprog: back on the topic of making a 7404 amplifier
12:27 PM polprog: the F serie is nonlinear
12:27 PM polprog: very
12:27 PM polprog: i havent tried LS, LS has the linear region slightly lower
12:27 PM polprog: 74LS04: 1.3V - 3.8V @ Vcc=5V
12:27 PM polprog: 74F04: 1.5V - 4.0V @ Vcc=5V
12:28 PM polprog: 74AC04 no linear region
06:23 PM polprog: https://polprog.net/rozne1/ircjunk/logicamp/logicamp.html
06:48 PM rue_mohr: hi
06:48 PM polprog: hey
06:48 PM polprog: back from work?
06:49 PM rue_mohr: one bit computer!
06:49 PM rue_mohr: polprog, if you want linear, use a CD4011
06:49 PM rue_mohr: yea
06:49 PM polprog: i was thinking about starting to build a wire wrapped 87C51
06:49 PM polprog: hmm, i was to test the 4k series
06:50 PM polprog: well. with the spectrum analyzer i can work out the gain bandwidth product
06:50 PM rue_mohr: is that one that you can program via a serial port?
06:50 PM polprog: idk
06:50 PM rue_mohr: like, normal serial
06:50 PM polprog: its an mcs51 with a uv window
06:50 PM polprog: but i dont remeber if it had the serial loader
06:50 PM polprog: i have some atmel ones with flash memory
06:50 PM rue_mohr: oh that uv
06:50 PM rue_mohr: ok
06:51 PM polprog: i also have a handful of PLCC OTP ones but i could force them to run from external eeprom by grounding a pin
06:51 PM rue_mohr: aandrew, this is cool
06:52 PM polprog: i should experiment with feedback on that inverter amplifier
06:52 PM rue_mohr: polprog, yea, I kept quite a few with that pin
06:52 PM polprog: :)
06:52 PM polprog: ive got 20-ish of the PLCC ones
06:52 PM polprog: and got the sockets the other day too
06:52 PM polprog: another project that was put away for months now :/
06:54 PM rue_mohr: keep project boxes
06:55 PM polprog: yeah i collect trays
06:55 PM polprog: it works
06:55 PM polprog: i also remembered i have the linear CCDs untouched
06:56 PM polprog: and three RP2040s
06:58 PM Tom_L: hi
06:58 PM polprog: hey
07:05 PM polprog: i should eat something and go to sleep
07:05 PM polprog: and finish cleaning the lab up tomorrow
07:05 PM polprog: nighters
07:07 PM rue_mohr: I'm going ot ponder this 1 bit computer
07:08 PM rue_mohr: I wish he'd done an "instruction set"
07:09 PM rue_mohr: I guess its like my old program did up
07:10 PM rue_mohr: aandrew, can you run a dos program?
07:11 PM rue_mohr: his instruction would be something like if (input(a)) { output(b); goto(c)} else { output(d); goto(e)}
07:24 PM rue_mohr: its kinda neat how that can be the root of a modern language
07:49 PM aandrew: rue_mohr: I have a windows VM but that's about as close as I can get to it
07:57 PM rue_mohr: it doesnt need hardware a dos window might do it
07:58 PM rue_mohr: its an 8 bit version of his 1 bit computer
07:58 PM rue_mohr: but its the programming interface
09:04 PM Tom_L: things are pickin up around here
09:06 PM Tom_L: what can you do with a 1 bit computer?
09:06 PM aandrew: not much. just a bit of computing, really
09:07 PM Tom_L: pun intended?
09:07 PM aandrew: naturally
09:07 PM aandrew: but that design wasn't a one bit computer at all
09:07 PM aandrew: it was a rather elaborate state machine
11:26 PM rue_mohr: in that article is a 'smarter' io controller
11:26 PM rue_mohr: plc like thing
11:26 PM rue_mohr: yea, thats what got me, its a LOT like my state macines
11:26 PM rue_mohr: but its just a bit more flexible
11:27 PM rue_mohr: my state machine is 1 n-bit input and 1 8-bit output
11:27 PM rue_mohr: his is 6 1-bit inputs and 5 1-bit outputs
11:28 PM rue_mohr: with 2 memory bits