Oh, what I mean is that the ATtiny85 has to run at 32 MHz to bit-bang a similar horizontal video resolution (lets ignore the color for a moment), and it doesn't have nearly enough RAM and ROM to run the same type of programs.@@kallewirsch2263
I feel it is sort of justified because inside those keyboards there is another microcontroller that complicates matters with their crazy multibyte and 11-bits-per-byte bidirectional PS/2 protocol. At least the older generation XT-keyboards could be handled with just the existing on-board shift register, but good luck finding those... PS/2 keyboards are still easy to get. And... it's tiny, off the main board and out of sight :-)
@@beopstek With RAM and ROM, I agree. Of course, that's why this implementation of the AVR architecture is a "Tiny". But for the video output. Sorry, to disappoint you, But it has been done. 160*120 pixel is way within reach of the speed of an AVR While I could not find that exact project right now, here is another one www.serasidis.gr/circuits/AVR_VGA/avr_vga.htm Mega16 (same AVR architecture, with more memory), 16Mhz, 640*480 pixel, monochrome.
@@kallewirsch2263 Ah that's cool. How are the pixels formed? I studied the Quark-85 project and it needs 5 cycles to push a single pixel out of the ATtiny.
Thanks David! When we started this project from scratch in the beginning of last year, it was supposed to become a 4-bitter in TTL logic that could just play Tic Tac Toe on a LED matrix. We didn't expect that it would kind of approach home computer level. At this point it has pretty much achieved most of our own "dream computer” goals. And... it *finally* plays Tic Tac Toe as originally intended! This particular version of the game was indeed written in the 1970s, by Tom Pittman. The other new built-in games were written by Gigatron users BTW. The Foenix C256 is very cool and Stéphanie progresses rapidly. The updated C64-mini gets good reviews now as well, looking forward to that episode. It has been a fruitful year for 8-bit retro computing.
@@legend_darkstar David uploaded the video early and set it to private. That's why there's a comment from so early because he viewed it from a personal link
@@38911bytefreeThe gigatron runs at 6.25 MHz, while the ATtiny85-20PU on the keyboard adapter runs at 8 MHz, and also does several times as much work per clock using its much more powerful AVR instruction set. If you want to count overclocking, the Gigatron FAQ says you can probably get up to 10MHz if you swap out all the gates for faster 74F series parts and get faster RAM, while for an ATtiny85-20PU has 20MHz listed right on the datasheet, and can easily be pushed to 30MHz without too much trouble.
One of the advantages of smaller is faster. We learned that in the late 1950s with vacuum tube machines, and re-learned is practically every generation of machines after that. This TTL machine runs at 6+MHz, the first TTL-like (actually CTL) mainframe I worked on ran at 2 MHz. And you could do all of the data processing for a chain of a dozen banks on that one machine at the time.
not really as it is an attiny85 microcontroller 8k of flash, 512 bytes of ram, 512 bytes of eeprom and as fast as it can go is 20 mhz, i2c, and spi as interfaces
The load / save via the serial / keyboard interface is almost exactly how the classic Ohio Scientific Superboard single board computer handled the cassette interface, so watching the data slowly 'typing' in on the screen made me very nostalgic. :)
Also pretty much exactly how you'd load/save using paper tape via a reader/punch on the side of a teletype pressed into service as a terminal for a minicomputer or one of the very early micros. To the computer, the loading looked just like someone typing the program in (either to the BASIC prompt, or a machine code monitor) as fast as the teletype serial line would allow (ie, 110 baud, or about 10 characters per second), and saving looked just like LISTing but with a pause between issuing the command and the list actually happening (so you could cue up the paper tape punch and then hit Enter to start the dump), again at line speed. And to the teletype, it made no difference whether it was a computer at the other end, another teletype receiving and printing the data (or someone typing back very fast), or another attached tape reader and punch. The tapes literally just storing the notional keypresses or printed characters of the program, and indeed the stored code being equal to the pulses sent down the serial cable (5-hole tape for 5-pulse encoding, with shifted characters needing two spaces on the tape and two serial "bytes", which is why the 110 baud signal rate doesn't quite translate into a definite character rate; with a couple of stop bits and a start bit added on, and only a 62-character set - uppercase, numbers, a few symbols and two shifts - you got a mix of 8 and 16 bit pulse trains for each actual character), so they were essentially a record of what you wrote - including backspaces over errors, if you made any whilst live-punching - just without the pauses between keystrokes...
The smallest microcontroller in mass production is probably the ATMEL ATTiny4: about the size of a grain of rice in an SOT23-6 package. I used a handful of them for a battery-powered project several years back because of their super low power consumption.
I love really low-powered computers, but the original Gigatron was just too limited even for my tastes. This update is a huge improvement, and suddenly this seems like a fun and worthwhile project. Thanks for reviewing the new version!
It's an interesting project, but for me, not being able to easily save BASIC programs with a file name would be a deal breaker. I love programming, especially programming vintage computers, and that's mainly what I would want this for. If they come up with a better, less awkward way to save files, like maybe to a flash drive or sd card, then I'll seriously consider buying one of these computers.
just here to say that you really got me into retro brite and I recently retro brited my 2008 white apple pro keyboard, and it went phenomenal, sadly there is no footage but I hope you can believe me when I say thanks, and I love your videos, keep up the good work.
Okay, I have to admit. The idea of storing your software inside of the keyboard adapter's microcontroller, is just so nerdy. Then, moving screen RAM location so that the machine spews its RAM onto the screen - that is also SO COOL!
Excellent update. Nice choice of keyboard. I have black Cherry with USB interface, which I use with an old Intel Mac mini. It came with it. ML switches.
Glad to see they are keeping up with what people want and revising the ROM on it and offering the little peripherals. Would be cool to hang on the wall and just have it run a program where it just does random things and flashes the lights. Geek art!
0:55 A MICROCONTROLLER?!/!?!/1??!/!?!???????????????????????????!!!!!!!!!!!!! _(insert a wacky joke about how this defeats the purpose of Gigatron that inevitably someone will not understand and would point out that this is not the computer itself but rather an accessory for it or something else)_
A keyb need an interface that is not trivial to implement. A C64 was a matrix keyb (much simpler than a PS2 readout) and still used part of a CIA for the scan.
I know - I wanted to mention the difficulty of implementing this feature without a microcontroller in the parentheses too, but it was too long already.
FloppyDriveMaestro A raw EEPROM or flash chip would be simpler. Or wiring an SDcard socket to an I/O port and bit-banging it like already done by Arduino libraries.
"Dream Computer". I am fully onboard with your idea. I will support it in any way you make available. I work in the Sheet Metal industry and can make any light gauge mounts, brackets, etc that could be needed. I haven't really played with programing much sense my dad brought home a TRS-80 back in the early 80s. I've tinkered with Python and c++ but I've been wanting to play on actual hardware like a c64. Found your channel years ago and it has added fuel to those desires. I've checked ebay off and on for the past few years but the prices, and the way a lot of descriptions seem to leave a grey area,.. I've been reluctant to buy that way. (And now I own one!) So I do hope there will be some real movement on your dream computer and I would like to be a contributor at day 1. I did try to join your website to reach out but the Login/Join link only lets me attempt a login. Love the channel!
Thanks for the update on the Gigatron, after seeing your last video (just recently) I ordered one, hopefully it will arrive this week. look forward to the c64 mini update video.
I was going back through the videos and found these on the Gigatron. They don't make them any more but I bought a PCB today. Time to start buying ICs I guess.
Love the Gigatron! That's just such an amazing thing to have to play with! When you make the C64 Mini checkup, I hope you find the time to shed some light on the future of it's BASIC mode, for a minute. Currently there still is no way to just select from a few floppy images without the emulation being completely restarted, which makes it impossible to treat BASIC like you would the real hardware. Which is something I'd pretty much like to do: start everything straight from BASIC, like the SidTracker, and have my own instrument floppy images to pick from.
I like your channel, Dave. You got an early retirement and get to have some fun with old computers from an era most people wouldn't pay one iota of attention to.
Tadgh B - if you've got a spare few hundred dollars going begging for what is essentially a novelty project, then yeah why not. Actually, when you've done that, why not buy them a new car each - in kit form obviously(!) Hours of fun....
That little ps/2 connector with the microcontroller on has made this little TTL computer a whole lot bigger. I'm tempted to build this for my collection. Thanks for the update Dave 😁😁😁 Kim 😁😁😁
What would be really cool with your dream computer you mentioned is some sort of serial port and monitor rom that you can debug and monitor programs running on the cpu on a modern pc. Not sure how possible that is with a 6502. At least you could debug,debug and load/dump memory. Thats just my opinion anyway
Love it. The color line tests kinda remind me of some older programs for the Apple ][ GS, or maybe the After Dark screensavers for early Mac computers (like the Color Classic or Quadra).
1:05 That's actually a microcontroller from the 90's or early 2000's at most. There's way way smaller ones. Have a look over at EEV blog's channel about the Padouk microcontrollers.
I think the audio sounds fuzzy because it essentially has the same problem as the video. I assume, after smoothing, it would sound a bit like crossover distortion.
If you could get the Arduino code for the keyboard interpreter then you could modify it to load a big basic program from sdcard, you would be able to automate any keyboard inputs you need just by modifying they code to do the work for you. Just a thought. It would be a lot easier to write your Sprite program on another computer using tiny basic, and then sending it to the custom built computer with the Arduino interface.
You mean the C++ code (because Arduino code is C++) or maybe C/assembly code for this task. It is a good idea to add a sdcard to the keyboard interpreter.
@@ConfuSomu Arduino uses a few versions of Atmel microcontrollers like the AtMega, they like all micro controllers and processors use machine code, but yes we program them in c/asm. I say Arduino code because that's what most hobbyist know it as.
Yeah, the microcontroller could probably be coerced, with a little bit of smart programming, into acting as a tape interface using an S-Video to 2xRCA cable (one mono out, one mono in) plugged into the PS/2 port. In fact you could keep the keyboard connected at the same time, as the PS/2 standard allows for connecting a keyboard and mouse through the one 6-pin socket using a Y-cable* , though as that usually requires one pin each for Vcc, Ground, Clock and Data, you might need to go down to just a single bidirectional RCA using the fallow mouse-specific pins, unless you share the ground and have e.g. outbound on Clock and inbound on Data. * (each uses only 4 of the 6 pins, and only retains the full connector instead of having lopsided 4-of-6 plugs because it's just simpler and cheaper to use a single type and internally wire up the necessary pins; that's also why you can't chop and change which port you plug in to on a 2-port machine, but can plug in either a keyboard or mouse without an adaptor on a laptop) The audio save/load hardware on old computers wasn't any more complicated than a well-controlled 3- or 4-wire serial port, after all. The sampling comes down to "is the incoming voltage higher than a certain voltage or not?", and output just toggles voltage on/off.
some pretty cool upgrades to that PC! I wonder if the BASIC has a 'clear screen' command, I'd use that for like the tic-tac-toe to refresh the screen instead of printing a bunch of lines it would definitely make it more elegant.
Awesome I was really hoping you would cover the N. American version of the C64 Mini as I'm looking to get one for my collection when I have the extra money to do as such.
Das blinken lights reminds me of a parallel port interface I built (LPT is bit addressable). Made a simple program in basic to make it into a binary counter with LEDs.
WOW this is funny, because this is usually what BASIC looked like to me with either a giant magnifier or ZoomText as a teen/college. Couldn't see worth a damn, but I always taught my friends BASIC when they came over. I was always known at work for being the guy who could turn any computer into a piano, and start playing funny tunes while training a class on the mysteries of NT4 and Infrared technology. MMm. Love those colors. Maybe there's just enough room for a blackjack game or a slot machine in keyboard storage.
Ah...those lovely lovely type in programs from the 80s. I (truly and honestly) miss those! Sure, half the time they didn't work and you'd have to comb through your several hundred lines of code to find where you goofed (or THEY did!) and fix it, but in the end there was a lot of satisfaction in getting it to work. And, as a side benefit, it really taught a lot about HOW to program for that particular machine (C64 in my case). One type in program that really blew my mind was a BASIC compiler: It was written in BASIC, but once you got it running you could have it compile its own code so that the NEXT time you ran it it would be MUCH faster. Very cool! And it was included free with the magazine! (Commodore Gazette, if I remember correctly)
Hi David, I poked around in homemade 8bit computers a bit. Many are $$$$ for some reason. But what about something like DansElectronics single AVR basic computer? The chips a couple bucks, is programmed with free arduino tools, and the rest is some basic parts. Maybe redesign the pcb to be able to plug in a few extras? I can help out in hw or sw if you like.
It's an achievement that it does so much with so few chips. Its software kernel reminds me of the Atari 2600 except it's using blank lines rather than overscan and VBLANK (presumably VGA also has a VBLANK). They just should have tried to give it more I/O capability than the one joystick port. That's the only real oversight I see in making it a fully functional foundation for a computer.
Can’t wait for the C64 mini video update. I’ve been thinking of buying one but it’s too close to Xmas and I have 3 boys to buy for first 😁 If I like the mini I’m gonna start collecting some real C 64 and or 128 stuff
Your definitely my favorite nerd on TH-cam. So insightful plus you always create one of a kind and unique content. I wish you continued success..! #KeepItRetro
Thanks, I enjoyed that. This reminds me of the Micromite Companion I built a few years ago. It is based on a rather unique micro controller that has native parallel processing. Like the gigatron, the video has to be generated entirely in software including the sync signals. Usually one or two cores are dedicated to generating video output and because of this unique design loads of different modes can be supported. It is a fascinating project.
if you think 8 pins is small check out daves recent "3 cent microcontroler" Its a 4 pin SMD microcontroler you can get in one off quantities for 3 cents.
The tetris music sounds very much like the "1-bit speaker coil" techniques used in many older ZX Spectrum 48k games. It could be a square wave, but many beeper music engines use programming magic and very thin pulsewidths to fake polyphony on what is truly 1-bit "Speaker is 100% On or it is 100% Off" limitations. Tim Follin's music for Agent X is a fantastic example of squeezing out 4 channel pseudo-polyphony from a 1-bit source.
I’d like to see them implement a real 8-bit micro (Z80/6502/6809/etc...) in TTL with 7-segment LED displays for it’s registers, and a run/slow/stop switch (which, in the “stop/step”) mode, enabled the LED displays, and lets you single-step through the machine-language code it’s running; a Propellor chip (like in the PE6502) would drive the video generation. It would incorporate a PS2 keyboard and mouse port.
What is the PS/2 keyboard you are using in your videos? It looks like a comfortable layout for the size. I'd have guessed it's a G84-4100, but looking closely this actually has a dedicated tilde key. BTW, I really like the idea of using a NES-on-a-chip as the basis of an inexpensive computer. With the bus exposed you could have all kinds of memory configurations on there. Personally I don't think composite-only is that much of a con. Inexpensive, small composite displays are still available if you don't have an old TV or monitor around.
Hi David, love this hobbyist machine, and am seriously considering one due to this update. One of the things the display made me think of is the old-style computer character generator programs used by early college and high school TV stations. Your all-colors demo was something that could have been used as intro or outro titles on video productions. In fact, there was one (not ProVideo Gold) for the Commodore 64 that I was trying to remember the name of. Do you know anything about this or can you or anyone reading recall the name?
I went and looked at Stephany's conference for the Foenix C256 at CEX, and wow that project looks really interesting! And also she looks like a kickass lady :) pretty proud to see a french canadian like her spearhead a notable project like this, since I'm french canadian myself (and she's from Québec City to boot, right near me)
I wonder if it changes depending on "speed mode"? It might be that it's only ever driving the output "high" during the blank lines, or even that it's only driving it high OR low and leaving it floating at 0v in between, which would make the waveform very "thin" (low duty cycle, like the saw-ish pulsewave of a Gameboy) and put some high frequency interference on the signal. Though, VGA runs at higher than audible frequency, so what you'd most likely pick up is the 1-of-4 cycling (plus Hblanks and particularly Vblanks if the sound cycle also ran in those areas, not that the Hblank would be long enough in of itself to create an audible sound... but it may contribute a white-noise effect on top of everything else).
1:00 You will be even more amazed about Atmel's ATtiny 5 (I think) microcontroller in a SOT23-6 package. Only 6 pins, and even tinier than that ATtiny 8.
If you wanna see small microcontrollers, search for "attiny sot-23-6". That thing is microscopic and only needs 0,2mA at 1.8V while still having 3 freely programmable pins.
The most expensive part of a modern microcontroller is the package. Using less pins makes them a lot cheaper and they still have all features. You just have to choose which pin is connected to which feature. The ATiny85 (DIP8) is even powerful enough to handle USB by software alone. It's built in PLL clock source is accurate enough so no external clock is used. So you get 3 free I/O pins plus USB interface. Using an I2C expander chip you can upgrade your Competition Pro to USB if you like.
Ah, colours. XD As usual, I can't help but think of the Atari 800XL I use most of the time if I mess around with an old computer. That's a 128/256 colour system which is nuts for anything from that era. (especially given the original models are from 1979) But what's weirdest is all the graphics modes and how you can abuse some of them. Everything from the 1.5 colour high resolution mode (referred to as 1.5 because it's two shades of the same colour), which gets you a resolution of up to 384x224 if you hack the display list, through the standard 'low resolution' 4 or 5 colour modes (the reasons it gets to 5 is pretty weird), which give an upper limit of about 192x224 resolution, but you can freely choose 4 (or 5 as the case may be) colours from 128. (technically 9 colours, since the sprite colours are independent of the background ones.) - all of these allow at least 3 variations in resolution (384/192, 320/160,256/128) But then the true weirdness begins once you get into the GTIA modes; There's 3 of them (which technically can be combined with other graphics modes, but most combinations don't make much sense.) - in each case it drops the maximum resolution down to 96/80/64 pixels per line (it remains 192 lines vertically though - or 224 with display list hacks.) So, the first is 16 shade monochrome. (you can choose any of the 16 colours, and get 16 shades of it -- the final stage of the colour circuitry isn't RGB, it's luma/chroma - so it makes sense - essentially this mode is choosing a single chroma value for the whole screen, and then a per pixel luma value - this is the only mode in which you legitimately have 256 shades to choose from. - the final video output stage is 8 bits, but it seems almost all the internal colour registers are 7 bit. Hence the confusion over whether the system has 256 or 128 colour output.) The second mode is effectively the opposite of the first. It's pretty awkward to use in practice really. But it gives you all 16 possible colours, but with the same intensity. (eg. Fixed luma for the whole screen, but with per pixel chroma values. - only 128 colours possible though, because the luma value can only specify the upper 3 bits.) The third mode is 9 colour palette mode. This uses all 9 of the hardware palette registers, and thus gives you a true 9 colour display (since that's the total number of colour registers the system has) - any 9 of the 128 colours is valid. Again this mode produces an additional limitation - it entirely disables the sprite hardware. (the Atari's sprite hardware is pretty weak though, so sometimes it's a worthwhile tradeoff. Of course it also shares the low resolution of other GTIA modes.) Where it gets really crazy though is when you start using scanline interrupts to change modes on each scanline. The most fundamental of these is to alternate between the 16 shade monochrome (set to black and white), and 16 luminance mode. While it glitches a little, the end result is a true 256 colour mode, but with a screen resolution of no more than 96 by 96 at most. (and more likely 64x96) But, with a bit of extra thought, you can extend this to a 4096 colour mode, by sticking to the 16 shade monochrome mode, but alternating between 3 chrominance values. (take a guess as to which - yep. Red, Green and Blue) - the end result isn't ideal because none of the 16 possible chrominance ranges consists of pure primary colours, but it still works to some extent. Of course, you've sacrificed even more vertical resolution to do this - the best possible resolution in this mode effectively becomes 96x64 pixels in 4096 colours. And of course, you're using an interrupt and CPU time on every single scanline, plus to draw images in this mode means manipulating 4 bits per pixel for up to 96x192 pixels (18432 pixels - roughly 9 kilobytes of memory. Or sbout 6k if you drop to 64x64 resolution.). That's a LOT of memory to be messing with using an 8 bit CPU running at 1.79 mhz... Still, the fact that an 8 bit design from 1979 technically has a means of outputting 4096 colour RGB graphics at all (no matter how glitchy that might be) really gives you something to think about huh. XD I guess the fact some people call it the baby amiga makes a lot of sense, looking at that. (not forgetting it was designed by the same people as the amiga of course...)
I'm psyched to hear you're moving forward with The Dream Computer project. Its something I've been interested in myself for a long time. The C256 Foenix sounds like a great way to go, even if it ends up costing more for the finished computer. Have you ever designed/implemented your own custom kernel, BASIC interpreter, and assembler before? Seems like an enormous task.
Make a tape drive with an arduino and use it to store your programs. Just output the data to the serial port and use the arduino to modulate it like a modem. Or you can use the arduino to interface with an SD card using the serial interface of the card which is slow but you have megabytes or gygabytes of storage.
And now you're stuck with the ironic fact that the microcontroller in your keyboard adapter has more processing power than the entire Gigatron.
The ATtiny85 is a lot slower even at 8 MHz.
Oh, what I mean is that the ATtiny85 has to run at 32 MHz to bit-bang a similar horizontal video resolution (lets ignore the color for a moment), and it doesn't have nearly enough RAM and ROM to run the same type of programs.@@kallewirsch2263
I feel it is sort of justified because inside those keyboards there is another microcontroller that complicates matters with their crazy multibyte and 11-bits-per-byte bidirectional PS/2 protocol. At least the older generation XT-keyboards could be handled with just the existing on-board shift register, but good luck finding those... PS/2 keyboards are still easy to get. And... it's tiny, off the main board and out of sight :-)
@@beopstek
With RAM and ROM, I agree. Of course, that's why this implementation of the AVR architecture is a "Tiny".
But for the video output. Sorry, to disappoint you, But it has been done. 160*120 pixel is way within reach of the speed of an AVR
While I could not find that exact project right now, here is another one
www.serasidis.gr/circuits/AVR_VGA/avr_vga.htm
Mega16 (same AVR architecture, with more memory), 16Mhz, 640*480 pixel, monochrome.
@@kallewirsch2263 Ah that's cool. How are the pixels formed? I studied the Quark-85 project and it needs 5 cycles to push a single pixel out of the ATtiny.
Thanks David! When we started this project from scratch in the beginning of last year, it was supposed to become a 4-bitter in TTL logic that could just play Tic Tac Toe on a LED matrix. We didn't expect that it would kind of approach home computer level. At this point it has pretty much achieved most of our own "dream computer” goals. And... it *finally* plays Tic Tac Toe as originally intended! This particular version of the game was indeed written in the 1970s, by Tom Pittman. The other new built-in games were written by Gigatron users BTW.
The Foenix C256 is very cool and Stéphanie progresses rapidly. The updated C64-mini gets good reviews now as well, looking forward to that episode. It has been a fruitful year for 8-bit retro computing.
how were you able to write a comment so early?
@@legend_darkstar David uploaded the video early and set it to private. That's why there's a comment from so early because he viewed it from a personal link
Ich glaub es het mit Patreon zstue, @@rwsh1976
@@rwsh1976 No Problem ;) Same with french for me xd. Je ne parle pas baguette
Good stuff! Whenever (if ever?) will we see a dedicated cassette save interface or a dedicted SD card save interface for the Gigatron?
3:20 I love how you instinctively tried to type a quotation mark using the Commodore keyboard layout's shift+2.
It's also in the UK keyboard layout
And the Swedish
The keyboard controller has more calculation speed than the rest of the computer. ;-)
LOL, it is not that fast !!!!. Gates can be one order of magnitude above
@@38911bytefreeThe gigatron runs at 6.25 MHz, while the ATtiny85-20PU on the keyboard adapter runs at 8 MHz, and also does several times as much work per clock using its much more powerful AVR instruction set. If you want to count overclocking, the Gigatron FAQ says you can probably get up to 10MHz if you swap out all the gates for faster 74F series parts and get faster RAM, while for an ATtiny85-20PU has 20MHz listed right on the datasheet, and can easily be pushed to 30MHz without too much trouble.
One of the advantages of smaller is faster. We learned that in the late 1950s with vacuum tube machines, and re-learned is practically every generation of machines after that. This TTL machine runs at 6+MHz, the first TTL-like (actually CTL) mainframe I worked on ran at 2 MHz. And you could do all of the data processing for a chain of a dozen banks on that one machine at the time.
not really as it is an attiny85 microcontroller 8k of flash, 512 bytes of ram, 512 bytes of eeprom and as fast as it can go is 20 mhz, i2c, and spi as interfaces
and only 6 input/outputs
The load / save via the serial / keyboard interface is almost exactly how the classic Ohio Scientific Superboard single board computer handled the cassette interface, so watching the data slowly 'typing' in on the screen made me very nostalgic. :)
Also pretty much exactly how you'd load/save using paper tape via a reader/punch on the side of a teletype pressed into service as a terminal for a minicomputer or one of the very early micros. To the computer, the loading looked just like someone typing the program in (either to the BASIC prompt, or a machine code monitor) as fast as the teletype serial line would allow (ie, 110 baud, or about 10 characters per second), and saving looked just like LISTing but with a pause between issuing the command and the list actually happening (so you could cue up the paper tape punch and then hit Enter to start the dump), again at line speed. And to the teletype, it made no difference whether it was a computer at the other end, another teletype receiving and printing the data (or someone typing back very fast), or another attached tape reader and punch. The tapes literally just storing the notional keypresses or printed characters of the program, and indeed the stored code being equal to the pulses sent down the serial cable (5-hole tape for 5-pulse encoding, with shifted characters needing two spaces on the tape and two serial "bytes", which is why the 110 baud signal rate doesn't quite translate into a definite character rate; with a couple of stop bits and a start bit added on, and only a 62-character set - uppercase, numbers, a few symbols and two shifts - you got a mix of 8 and 16 bit pulse trains for each actual character), so they were essentially a record of what you wrote - including backspaces over errors, if you made any whilst live-punching - just without the pauses between keystrokes...
The smallest microcontroller in mass production is probably the ATMEL ATTiny4: about the size of a grain of rice in an SOT23-6 package. I used a handful of them for a battery-powered project several years back because of their super low power consumption.
1:00 "I didn't know you could get a microcontroller with so few pins."
Where have you been the past 20 years?
I love really low-powered computers, but the original Gigatron was just too limited even for my tastes. This update is a huge improvement, and suddenly this seems like a fun and worthwhile project. Thanks for reviewing the new version!
It's an interesting project, but for me, not being able to easily save BASIC programs with a file name would be a deal breaker. I love programming, especially programming vintage computers, and that's mainly what I would want this for. If they come up with a better, less awkward way to save files, like maybe to a flash drive or sd card, then I'll seriously consider buying one of these computers.
"Pluggy McPlugface"
There is no better name for a computer peripheral. XD
Just like there's no better name for a boat than "Boaty McBoatface".
Even better. XD
If you let the internet name something it's going to always be ____y Mc____face
@@MikeDest Internety McInternetface!
lol
just here to say that you really got me into retro brite and I recently retro brited my 2008 white apple pro keyboard, and it went phenomenal, sadly there is no footage but I hope you can believe me when I say thanks, and I love your videos, keep up the good work.
Okay, I have to admit. The idea of storing your software inside of the keyboard adapter's microcontroller, is just so nerdy. Then, moving screen RAM location so that the machine spews its RAM onto the screen - that is also SO COOL!
Excellent update.
Nice choice of keyboard. I have black Cherry with USB interface, which I use with an old Intel Mac mini. It came with it. ML switches.
Glad to see they are keeping up with what people want and revising the ROM on it and offering the little peripherals. Would be cool to hang on the wall and just have it run a program where it just does random things and flashes the lights. Geek art!
if all you want is some blinky lights, you could do that with just the at tiny on the keyboard adaptor.
0:55 A MICROCONTROLLER?!/!?!/1??!/!?!???????????????????????????!!!!!!!!!!!!!
_(insert a wacky joke about how this defeats the purpose of Gigatron that inevitably someone will not understand and would point out that this is not the computer itself but rather an accessory for it or something else)_
A keyb need an interface that is not trivial to implement. A C64 was a matrix keyb (much simpler than a PS2 readout) and still used part of a CIA for the scan.
I know - I wanted to mention the difficulty of implementing this feature without a microcontroller in the parentheses too, but it was too long already.
He said *P R O C C E S O R !*
A MICROPROCESSOR IS LACKING!
@@equinoxonroblox
yes that's the joke and that's what I've outlined in my _(blah blah)_ addendum
@@Architector_4 or in other words: *r/wooosh*
Such a great update, kudos to the guys developing this computer
Nice follow-up, I already liked the idea behind this product a lot when I watched you introducing it!
That with moving the screen memory is pretty neat where you can see what's in the RAM live on the screen. Pretty cool
There is microcontrollers with 6 pins in SOT23-6 package. Just 3*4mm. And there is even smaller versions in BGA.
Very cool upgrades! I think I might have to buckle down and get me one of these now!
That is awesome. I just wish there was a way to store programs on literally any sort of external media. A tape interface would do.
Punch tape interface for style! :D
FloppyDriveMaestro A raw EEPROM or flash chip would be simpler. Or wiring an SDcard socket to an I/O port and bit-banging it like already done by Arduino libraries.
@@johnfrancisdoe1563 Anything would do. I would be happy with what ever is easiest for the devs to implement.
"Dream Computer". I am fully onboard with your idea. I will support it in any way you make available. I work in the Sheet Metal industry and can make any light gauge mounts, brackets, etc that could be needed.
I haven't really played with programing much sense my dad brought home a TRS-80 back in the early 80s. I've tinkered with Python and c++ but I've been wanting to play on actual hardware like a c64. Found your channel years ago and it has added fuel to those desires. I've checked ebay off and on for the past few years but the prices, and the way a lot of descriptions seem to leave a grey area,.. I've been reluctant to buy that way. (And now I own one!)
So I do hope there will be some real movement on your dream computer and I would like to be a contributor at day 1.
I did try to join your website to reach out but the Login/Join link only lets me attempt a login.
Love the channel!
Thanks for the update on the Gigatron, after seeing your last video (just recently) I ordered one, hopefully it will arrive this week. look forward to the c64 mini update video.
Keep up the work man. I'm absolutely in love with your videos
So this is how the old days of enthusiast kit microcomputers looked like back in the 1970s.
Good to know someone is still keeping that spirit alive.
I was going back through the videos and found these on the Gigatron. They don't make them any more but I bought a PCB today. Time to start buying ICs I guess.
Protip: You could use a hardware keylogger to save your programs, some are able to "type back" the data they capture.
Love the Gigatron! That's just such an amazing thing to have to play with! When you make the C64 Mini checkup, I hope you find the time to shed some light on the future of it's BASIC mode, for a minute. Currently there still is no way to just select from a few floppy images without the emulation being completely restarted, which makes it impossible to treat BASIC like you would the real hardware. Which is something I'd pretty much like to do: start everything straight from BASIC, like the SidTracker, and have my own instrument floppy images to pick from.
What an excellent learning project. They built a PDP-11 (kind of).
Until I've had my coffee, I'm like the Gigatron running in slow mode.
Your display is clearer and more vivid?
I like your channel, Dave. You got an early retirement and get to have some fun with old computers from an era most people wouldn't pay one iota of attention to.
You got to love that they labeled the blinkenlights with "blinkenlights" on the circuit board.
there is a computer that was called KAT, made from a company called gigatronics. It was an appleII/IBM compatible hybrid, and good luck finding one.
I so want a few of these for my boys and well one for me. What a great project to teach them with. Love it
Tadgh B - if you've got a spare few hundred dollars going begging for what is essentially a novelty project, then yeah why not. Actually, when you've done that, why not buy them a new car each - in kit form obviously(!) Hours of fun....
The microcontroller is an attiny85 and works with the arduino IDE. Not as powerful of course but for its size it's pretty awesome.
Another great episode. I see you're fast approaching 1M viewers, well deserved.
That little ps/2 connector with the microcontroller on has made this little TTL computer a whole lot bigger. I'm tempted to build this for my collection. Thanks for the update Dave 😁😁😁 Kim 😁😁😁
Boom - Tetris for David!
Ooh, neat. I love that Tetris clone, especially the halfsawed wave music.
Always interesting to see your updates and relive the computing that once was. If you were born in the 70s/80s you really are lucky.
What would be really cool with your dream computer you mentioned is some sort of serial port and monitor rom that you can debug and monitor programs running on the cpu on a modern pc. Not sure how possible that is with a 6502. At least you could debug,debug and load/dump memory.
Thats just my opinion anyway
The Gigatron was the computer without a microcontroller. The keyboard interface has a microcontroller. Now the Gigatron has a microcontroller.
This is a real step forward and rather a neat little computer. Really like your mini keyboard - which one is it David?
Thought it was a happy hacking keyboard but now I want to know for sure
It's a Cherry. Search for Cherry mini keyboard. I've got the black USB version
@@flambo1500 Cherry
Love it.
The color line tests kinda remind me of some older programs for the Apple ][ GS, or maybe the After Dark screensavers for early Mac computers (like the Color Classic or Quadra).
1:05 That's actually a microcontroller from the 90's or early 2000's at most. There's way way smaller ones. Have a look over at EEV blog's channel about the Padouk microcontrollers.
I think the audio sounds fuzzy because it essentially has the same problem as the video. I assume, after smoothing, it would sound a bit like crossover distortion.
I appreciate that thing for it's high novelty factor. thanks for the content.
I think it's a cool computer, I don't see anything really at this level out there. Would be amazing for a computer class.
If you could get the Arduino code for the keyboard interpreter then you could modify it to load a big basic program from sdcard, you would be able to automate any keyboard inputs you need just by modifying they code to do the work for you. Just a thought. It would be a lot easier to write your Sprite program on another computer using tiny basic, and then sending it to the custom built computer with the Arduino interface.
You mean the C++ code (because Arduino code is C++) or maybe C/assembly code for this task.
It is a good idea to add a sdcard to the keyboard interpreter.
@@ConfuSomu Arduino uses a few versions of Atmel microcontrollers like the AtMega, they like all micro controllers and processors use machine code, but yes we program them in c/asm. I say Arduino code because that's what most hobbyist know it as.
Yeah, the microcontroller could probably be coerced, with a little bit of smart programming, into acting as a tape interface using an S-Video to 2xRCA cable (one mono out, one mono in) plugged into the PS/2 port. In fact you could keep the keyboard connected at the same time, as the PS/2 standard allows for connecting a keyboard and mouse through the one 6-pin socket using a Y-cable* , though as that usually requires one pin each for Vcc, Ground, Clock and Data, you might need to go down to just a single bidirectional RCA using the fallow mouse-specific pins, unless you share the ground and have e.g. outbound on Clock and inbound on Data.
* (each uses only 4 of the 6 pins, and only retains the full connector instead of having lopsided 4-of-6 plugs because it's just simpler and cheaper to use a single type and internally wire up the necessary pins; that's also why you can't chop and change which port you plug in to on a 2-port machine, but can plug in either a keyboard or mouse without an adaptor on a laptop)
The audio save/load hardware on old computers wasn't any more complicated than a well-controlled 3- or 4-wire serial port, after all. The sampling comes down to "is the incoming voltage higher than a certain voltage or not?", and output just toggles voltage on/off.
There is a Spanish heavy metal/parody band called Gigatron.
some pretty cool upgrades to that PC! I wonder if the BASIC has a 'clear screen' command, I'd use that for like the tic-tac-toe to refresh the screen instead of printing a bunch of lines it would definitely make it more elegant.
You know, gigatron's sound chip sounds like... Harmonics or something that uses those long paper sheets to play notes.
Awesome I was really hoping you would cover the N. American version of the C64 Mini as I'm looking to get one for my collection when I have the extra money to do as such.
Holy nuts...I just looked up quad hands on Amazon and found that there's a variety of them priced between $40 and $75!
We follow you from Italy and we love you so much! Keep it up!
Das blinken lights reminds me of a parallel port interface I built (LPT is bit addressable). Made a simple program in basic to make it into a binary counter with LEDs.
WOW this is funny, because this is usually what BASIC looked like to me with either a giant magnifier or ZoomText as a teen/college. Couldn't see worth a damn, but I always taught my friends BASIC when they came over. I was always known at work for being the guy who could turn any computer into a piano, and start playing funny tunes while training a class on the mysteries of NT4 and Infrared technology. MMm. Love those colors. Maybe there's just enough room for a blackjack game or a slot machine in keyboard storage.
Really interesting! But you didn't show the WozMon! I assume it is some kind of machine code monitor???
When ever you get around to building your 8 Bit SBC, make sure to run planet X2 on the system, it just seems right that it should do that.
Ah...those lovely lovely type in programs from the 80s. I (truly and honestly) miss those! Sure, half the time they didn't work and you'd have to comb through your several hundred lines of code to find where you goofed (or THEY did!) and fix it, but in the end there was a lot of satisfaction in getting it to work. And, as a side benefit, it really taught a lot about HOW to program for that particular machine (C64 in my case).
One type in program that really blew my mind was a BASIC compiler: It was written in BASIC, but once you got it running you could have it compile its own code so that the NEXT time you ran it it would be MUCH faster. Very cool! And it was included free with the magazine! (Commodore Gazette, if I remember correctly)
Hi David, I poked around in homemade 8bit computers a bit. Many are $$$$ for some reason. But what about something like DansElectronics single AVR basic computer? The chips a couple bucks, is programmed with free arduino tools, and the rest is some basic parts. Maybe redesign the pcb to be able to plug in a few extras? I can help out in hw or sw if you like.
Since you can change the screen ram location, to get smooth scrolling (like how those demo pictures slide in) you can write a barrel scroller routine.
It's an achievement that it does so much with so few chips. Its software kernel reminds me of the Atari 2600 except it's using blank lines rather than overscan and VBLANK (presumably VGA also has a VBLANK). They just should have tried to give it more I/O capability than the one joystick port. That's the only real oversight I see in making it a fully functional foundation for a computer.
Can’t wait for the C64 mini video update. I’ve been thinking of buying one but it’s too close to Xmas and I have 3 boys to buy for first 😁 If I like the mini I’m gonna start collecting some real C 64 and or 128 stuff
You forgot to show the wozmon program
Man... Your channel is secretly my favorite.
Your definitely my favorite nerd on TH-cam. So insightful plus you always create one of a kind and unique content. I wish you continued success..! #KeepItRetro
It sux-ed typing 1000s of lines out of that book in the early 80s, which I still have on my shelf.
Thanks, I enjoyed that. This reminds me of the Micromite Companion I built a few years ago. It is based on a rather unique micro controller that has native parallel processing. Like the gigatron, the video has to be generated entirely in software including the sync signals. Usually one or two cores are dedicated to generating video output and because of this unique design loads of different modes can be supported. It is a fascinating project.
congrats on 800k david!
This is another 8 Bit Guy video.
On the Gigatron!
Very nice! It has a certain, pleasing retro feel to it that I like. Somewhere between a C64 and an Amiga (colours). ;)
Great for soldering skilled peoples and talented programmers.
if you think 8 pins is small check out daves recent "3 cent microcontroler" Its a 4 pin SMD microcontroler you can get in one off quantities for 3 cents.
The tetris music sounds very much like the "1-bit speaker coil" techniques used in many older ZX Spectrum 48k games. It could be a square wave, but many beeper music engines use programming magic and very thin pulsewidths to fake polyphony on what is truly 1-bit "Speaker is 100% On or it is 100% Off" limitations.
Tim Follin's music for Agent X is a fantastic example of squeezing out 4 channel pseudo-polyphony from a 1-bit source.
I’d like to see them implement a real 8-bit micro (Z80/6502/6809/etc...) in TTL with 7-segment LED displays for it’s registers, and a run/slow/stop switch (which, in the “stop/step”) mode, enabled the LED displays, and lets you single-step through the machine-language code it’s running; a Propellor chip (like in the PE6502) would drive the video generation. It would incorporate a PS2 keyboard and mouse port.
The Gigatron can run 6502 programs
What is the PS/2 keyboard you are using in your videos? It looks like a comfortable layout for the size. I'd have guessed it's a G84-4100, but looking closely this actually has a dedicated tilde key.
BTW, I really like the idea of using a NES-on-a-chip as the basis of an inexpensive computer. With the bus exposed you could have all kinds of memory configurations on there. Personally I don't think composite-only is that much of a con. Inexpensive, small composite displays are still available if you don't have an old TV or monitor around.
You can get a very fast ARM microcontroller in 8-pin DIP; it's called the LPC810.
WOW, checked the datasheet. Worth having the part handy. Tha nks.
Nice Famicom controller there! Didn't know it came with that.
I always wonder how fast a C64 or ZX SPectrum could draw lines and circles with a proper bresenham implementation. One of these days I have to do it.
imagine this in the 80’s it would be amazing
This actually makes me much more interested in getting one of these.
"Planet X: Giga" when? :p
Planet X Zero, most likely. ;-)
OMSI-Fan Mark
Or maybe Planet X One, not to be confused with Planet X1 :)
what are we, xbox? :P
Hi David, love this hobbyist machine, and am seriously considering one due to this update. One of the things the display made me think of is the old-style computer character generator programs used by early college and high school TV stations. Your all-colors demo was something that could have been used as intro or outro titles on video productions. In fact, there was one (not ProVideo Gold) for the Commodore 64 that I was trying to remember the name of. Do you know anything about this or can you or anyone reading recall the name?
I went and looked at Stephany's conference for the Foenix C256 at CEX, and wow that project looks really interesting! And also she looks like a kickass lady :) pretty proud to see a french canadian like her spearhead a notable project like this, since I'm french canadian myself (and she's from Québec City to boot, right near me)
We need Gigatron+ with 128Kb, hardware sprites support and a dedicated audio circuit... and with a FDD support too!
Can you please upload a sound sample of the Gigatron "square wave"?
He just did, just run the video through audacity or something.
I want it to be clear
Sounds like it has little breaks with no sound, like it’s silent between scan lines. I like that dirty sound.
@@MikeDest Me too. That's why I want a sample xd
I wonder if it changes depending on "speed mode"? It might be that it's only ever driving the output "high" during the blank lines, or even that it's only driving it high OR low and leaving it floating at 0v in between, which would make the waveform very "thin" (low duty cycle, like the saw-ish pulsewave of a Gameboy) and put some high frequency interference on the signal. Though, VGA runs at higher than audible frequency, so what you'd most likely pick up is the 1-of-4 cycling (plus Hblanks and particularly Vblanks if the sound cycle also ran in those areas, not that the Hblank would be long enough in of itself to create an audible sound... but it may contribute a white-noise effect on top of everything else).
1:00 You will be even more amazed about Atmel's ATtiny 5 (I think) microcontroller in a SOT23-6 package. Only 6 pins, and even tinier than that ATtiny 8.
I'm sitting here, eating food and what do you know? David uploads!!!
If you wanna see small microcontrollers, search for "attiny sot-23-6". That thing is microscopic and only needs 0,2mA at 1.8V while still having 3 freely programmable pins.
what I'd be interested in seeing is a 68k based computer kit
Old school tv program - and that's meant positive. I always feel I get something more than just entertainment out the programs.
Good work! What a cute little machine. :-)
The most expensive part of a modern microcontroller is the package. Using less pins makes them a lot cheaper and they still have all features. You just have to choose which pin is connected to which feature.
The ATiny85 (DIP8) is even powerful enough to handle USB by software alone. It's built in PLL clock source is accurate enough so no external clock is used. So you get 3 free I/O pins plus USB interface. Using an I2C expander chip you can upgrade your Competition Pro to USB if you like.
That is a neat system. I may need to pick one up now :)
uncle doug
Ah, colours. XD As usual, I can't help but think of the Atari 800XL I use most of the time if I mess around with an old computer.
That's a 128/256 colour system which is nuts for anything from that era. (especially given the original models are from 1979)
But what's weirdest is all the graphics modes and how you can abuse some of them.
Everything from the 1.5 colour high resolution mode (referred to as 1.5 because it's two shades of the same colour), which gets you a resolution of up to 384x224 if you hack the display list, through the standard 'low resolution' 4 or 5 colour modes (the reasons it gets to 5 is pretty weird), which give an upper limit of about 192x224 resolution, but you can freely choose 4 (or 5 as the case may be) colours from 128. (technically 9 colours, since the sprite colours are independent of the background ones.) - all of these allow at least 3 variations in resolution (384/192, 320/160,256/128)
But then the true weirdness begins once you get into the GTIA modes;
There's 3 of them (which technically can be combined with other graphics modes, but most combinations don't make much sense.) - in each case it drops the maximum resolution down to 96/80/64 pixels per line (it remains 192 lines vertically though - or 224 with display list hacks.)
So, the first is 16 shade monochrome. (you can choose any of the 16 colours, and get 16 shades of it -- the final stage of the colour circuitry isn't RGB, it's luma/chroma - so it makes sense - essentially this mode is choosing a single chroma value for the whole screen, and then a per pixel luma value - this is the only mode in which you legitimately have 256 shades to choose from. - the final video output stage is 8 bits, but it seems almost all the internal colour registers are 7 bit. Hence the confusion over whether the system has 256 or 128 colour output.)
The second mode is effectively the opposite of the first. It's pretty awkward to use in practice really. But it gives you all 16 possible colours, but with the same intensity. (eg. Fixed luma for the whole screen, but with per pixel chroma values. - only 128 colours possible though, because the luma value can only specify the upper 3 bits.)
The third mode is 9 colour palette mode. This uses all 9 of the hardware palette registers, and thus gives you a true 9 colour display (since that's the total number of colour registers the system has) - any 9 of the 128 colours is valid. Again this mode produces an additional limitation - it entirely disables the sprite hardware. (the Atari's sprite hardware is pretty weak though, so sometimes it's a worthwhile tradeoff. Of course it also shares the low resolution of other GTIA modes.)
Where it gets really crazy though is when you start using scanline interrupts to change modes on each scanline.
The most fundamental of these is to alternate between the 16 shade monochrome (set to black and white), and 16 luminance mode. While it glitches a little, the end result is a true 256 colour mode, but with a screen resolution of no more than 96 by 96 at most. (and more likely 64x96)
But, with a bit of extra thought, you can extend this to a 4096 colour mode, by sticking to the 16 shade monochrome mode, but alternating between 3 chrominance values. (take a guess as to which - yep. Red, Green and Blue) - the end result isn't ideal because none of the 16 possible chrominance ranges consists of pure primary colours, but it still works to some extent.
Of course, you've sacrificed even more vertical resolution to do this - the best possible resolution in this mode effectively becomes 96x64 pixels in 4096 colours.
And of course, you're using an interrupt and CPU time on every single scanline, plus to draw images in this mode means manipulating 4 bits per pixel for up to 96x192 pixels (18432 pixels - roughly 9 kilobytes of memory. Or sbout 6k if you drop to 64x64 resolution.). That's a LOT of memory to be messing with using an 8 bit CPU running at 1.79 mhz...
Still, the fact that an 8 bit design from 1979 technically has a means of outputting 4096 colour RGB graphics at all (no matter how glitchy that might be) really gives you something to think about huh. XD
I guess the fact some people call it the baby amiga makes a lot of sense, looking at that. (not forgetting it was designed by the same people as the amiga of course...)
your videos keep me going. thanks david.
I'm psyched to hear you're moving forward with The Dream Computer project. Its something I've been interested in myself for a long time. The C256 Foenix sounds like a great way to go, even if it ends up costing more for the finished computer. Have you ever designed/implemented your own custom kernel, BASIC interpreter, and assembler before? Seems like an enormous task.
Never ever change the intro tune!!
Make a tape drive with an arduino and use it to store your programs. Just output the data to the serial port and use the arduino to modulate it like a modem.
Or you can use the arduino to interface with an SD card using the serial interface of the card which is slow but you have megabytes or gygabytes of storage.
You can cheat at Tetris by increasing the scanlines and slowing down visual input.