Відео

I was looking for a channel like this forever.. I had this idea long time ago but my electronics skills were very limited to complete a project like this one. your channel is gold...Thank you!!

This thing would have destroyed in the PDP-8 days

there is no source code on the github

The TRS-80 used the Kansas CIty standard (or something similar) which was basically FSK. Two tones were recorded IIRC (1200 Hz and 2400 Hz) to represent the ones and zeros. The TRS-80 had minimal electronics for processing the signal into data. Didn't work very well either. I eventually used a reel-to-reel recorder and got somewhat better results. But it was a cheap solution since everybody had a cassette recorder they could use. Bill Gates played a small role in the development.

I had a TRS-80 that used a cassette recorder to store programs. You could buy games (like chess) on cassettes. They used a method called the "Kansas City standard." Unfortunately, the Trash 80 did do much (any) signal processing so storing programs was always problematic. Better than front panel switches and more available than paper tape, but very kludgly.

Much more elegant than the version I mangled together. Thanks...

wouaaaa!!!!! amazing concept, sorry my english im french, you are the great teacher, merci beaucoup

In the emulator, the condition used to select between RAM and Flash is ((MAR & 0x8000) || (Bank & 0x80)). But this checks only the highest bit of MAR and behaves as if an active flash bank is mirrored throughout the low 32K of the address space. The manual states that "address space 0x1000..0xffff always represents RAM," so should the condition rather be ((MAR & 0xf000) || (Bank & 0x80))? As far I as can tell, this has no effect on emulating the OS because the OS only leaves flash mapped into the address space during boot-up, when copying some flash to RAM at 0xf000 (an address with highest bit set), and then it's unmapped until restart.

So went and built one. BTW, your advise about where you source chips is good. I sourced all from China. Most were good, I tested them before use. The one that does not test on a programmer though is the counter, 74hc161. 5 out of 10 were bad! After changing those, is promising. VGA won’t sync right now, Vsync and Hsync are good, video signal is all over though.

Great, thank you for sharing 👏💪👌

BRILLIANT TUTORIAL!

If I write incorrectly, can I erase the chip by using this PROM.exe and then reprogram it

Looked at BOM list and realized, I already have more than 1/2 the parts kicking around. Ok, gotta make one. :) I notice there is no reset circuit after power on. An RC circuit behind a Schmitt Trigger would suffice. Maybe there is unused one? Looking …. A reset would be nice for any analog monitor connection.

2:10 (Excuse the sligtly drunk comment.) HEY, the . . . point-metal-bits-tool is for people who have sausage fingers, and you don't have sausage fingers. You have small fingers. Put it in by hand, you pansy! P***Y! RAAAAGH! BEER! AND SO ON! Edit: I love that you call him "Nisse."

Amazing.

Fantastic! I think you can do it with only one chip to achieve RCA output, there are those libraries called TVout and PS2Keyboard you can load in one single chip so you can type and recieve with only one chip onstead of three! Please do a video about it :)

At this low amount of storage, wouldn't using a NOR flash instead of a NAND flash allow you to write and erase individual bytes instead of blocks cost effectively? (I haven't looked up the costs for this size of NAND and NOR flash memory.)

Love it. One thing I'd like to ask about though. Couldn't a section of the flash memory be reserved as a replacement for RAM now? I have no idea how much speed it would lose, but it would make for an even more minimal hardware setup, though it would require a bit more programming. Please be gentle with me, I speak from a place of ignorance.

And the Ftdi people always go on about ‘original’ suppliers end such. Go China! CH chips rock!

Back in day lex and yak were the tools to use to create a language.

Logo looks like good learning language.

Is there an LLVM target for your computer yet? :)

Thank you, I tried to use TommyProm32 drawing, but yours is way more clear and therefore easy to copy. Any chance your pcb is at pcbway in the share factory?

I love this, especially the paper tape input.

How to upload code from flash mamory to arduino or esp32? I mean how to use flash memory as bootloader.

Flutter and WOAH. LMFAO! love it.

Thanks

the source code for the assembler is missing on your github link. please reupload

in the video at 1.04 the key code comes first followed by F0 but the BREAK code from the Scan code is for the letter A, F0 1C is seen like this in the libraries. You show that the last data coming with the oscilloscope is F0. Scan tables show MAKE =1C, break =F0 1C. Which one is correct. Thanks

I like the off-the-beaten-track approach! It also seems to work very well for you, which helps :P Very cool video, I wish I had the skills to develop such a computer. Best I can do is an even more minimal CPU(-instruction set), because my brain is not big enough for more ;P

Still too complex to most

That's very neat indeed. I love the use of a /single/ dictionary for all kinds of identifiers. That's quite cool !

I just discovered your channel, and I am subscribed. Wow, you work miracles and are extremely knowledgable.

Is there a discord channel we can discuss subjects like this?

There is a company called potato semiconductor that sells ttl 7400 series chips that go up to 1 gigahertz. Another guy built a computer called Magic 1, He goes online by the name Bill Buzzbee.

I wonder what happens if i run Minimal 64 on scratch

Squeezing water from stone is a thing. Most of the hydtogen/water on Earth and Mars is locked into various minerals.

Awesome. Just what i needed. I'm using an Arduino to control 2 stepper motors to set a back gage on a 90 to press brake, and needed a simple way to feed the back gage setting for each bend of the steel into the Arduino so it can spin the servos to the right spot. I was going to use a nice touchpad, but found it has no keypad function and the interface to the Arduino is quite complex and the library is huge. This is very simple and compact.

Bit random but is the value of R27 meant to be zero?

Really clever way to solve this, I did several videos on pal/vga out from various small devices, even attiny13a

Wow!

Very interesting. All this must have been one hell of a lot of work, never mind the OS you wrote to run on it! Endless questions... one or two that spring to mind for now: -It would seem your architecture is somewhat 6502-like, but microcode rather than implemented in 'gates'. A compare / contrast might be nice. -Von Neuman vs Harvard architecture in TTL-based computers... I would be interested in your thought process. (Gigatron for comparison?) More... -I see you have the video RAM in the middle of memory, reasoning? I must take a careful look at your VGA implementation... colour..? (as a first thought I wonder if three banked pages for RGB bit planes, multiplexed??) -Audio..? I know, it's meant to be minimal system... but I wonder if an 'I/O waggle' like the PET or a COVOX-like solution might be interesting? -Flash banking for storage... I wonder if there's room to extend that to RAM for > 64k down the line? -Hmmm... microcode stored in flash so the CPU can rewrite it's own 'brain' on the fly... getting silly? I'm going to have to have a good look at this - many thanks!

What did you major in university

You are amazing if you can do this with a nano then you can do much with an esp32 wemos d1.Where can I learn about these things for a complete noob ! Self study though. Thanks

Where can I learn about low level stuff like logic gates , data bus and how computers work at hardware level

Just looking at your design, I think you can add some color at a cost of a couple more ICs. If you used two '166. Route the 8 bit data high nibble into one shift register and the low 4 bits into the other. Tie the serial output of one shift register to the Red, other to Green, for instance. You would have to slow the shift to half current speed to stretch the pixels would by twice as wide. Both '166 would have their [E, F, G, H] registers filled with a single byte/Write. You would encode color in the nibble i.e. byte 1001-1110 would clock out of the first'166 as 1011 would be Red, blank, blank, Red while the lower nibble would come out as Grn, Grn, Grn, blank, Grn. They would combine on the screen as Red+Grn, blank + Grn, Blank + Grn, Red +Blank, if I have it right. Of course if you had 4 '166, you could divide the byte up into 4 slices, but I'm not sure you need intensity. You can only get ~14 bits I/O right? It would be nice to change it on the fly with changing the shift out clock to 1/2 or full speed so you could just ignore the extra hardware when you wanted to just do high rez black and white. I think there is a universal shift register, something like a 74LS194, with all shifts output, but it's only 4 bits.

Wonderful! this is great. I really want to build this and also write an emulator for it so I can test my understanding of the system before the board gets here. Vielen dank!

Wow, this is mot impressive, informative and very interesting.

AMAZING!!!!

I had a thought, after watching this, your 'oddball' and 8-bit battle videos... not sure if this fits in your oddball aesthetic, but you're using eproms already... The ALU could be replaced with a single 16Mbit (1Mx16) eprom (like ST M27C160-50f1 which seems to be still available on ebay for £2... hopefully not fake) the 16 bits from A and B as address ofc, and since it has 20 lines then lookup tables for 15 2-input operations (carry-in as distinct operation), plus up to 256 single-input operations could be encoded with a control line to usurp the address inputs from the B register and connect to outputs from the control ROM instead. This would allow a whole range of 1-cycle math and logic ops to be encoded, plus drastically reducing the cycles for others... I suggest (2-input µops): add, add+1 (carry set equiv.), sub, sub-1 (carry set equiv.), multiply (low byte result), multiply (high-byte result), and, or, xor, shl-double(x1,2,4 bits), shr-double (1,2,4 bits). And then (1-input µops): shl(1,2,3,4,5,6,7 bits), shr(1,2,3,4,5,6,7 bits), sar(1,2,3,4,5,6,7 bits), rol(1,2,3,4,5,6,7 bits), rol-carry(1,2,3,4,5,6,7,8 bits) not, neg, inc, dec... maybe some flag-based variants like inc-carry, inc-z, inc-n, not-n, not-c, not-z, neg-n etc, although these could also be encoded as conditional execution ops (see below). would probably want a wider control eprom, so maybe using 2 16-bit wide eproms like the one above would work? then the total chip count might actually end up less. also, I'm imagining some flag-controlled optional execution variants of some instructions could be good for when only one or two instructions would need to be bypassed by a branch. That wouldn't need any logic change at all, just microcode. but all in all, I'm very impressed by how much you're doing with so little - mostly in microcode, like using the adder for shifts and rotates (encoding logical and arithmetic right-shifts as well might make sense).