AndresNavarro

Great times. I remember playing something like this on a telnet server on '96, I think they are still some servers running today: https://www.freechess.org/Help/HelpFiles/addresses.html

> But the author does themselves no favour by including this incorrect tidbit in the article:

As I undertood it, that tidbit comes from Sandisk and probably targets Windows user. I also believe Windows does (or did) use base 2 for file and disk sizes

> ...but I think the way the original VT52 handled scrolling was that it incremented a register which it used for the index of the starting line

That's exactly right, pretty cheap but has some limitations like you point out here:

> (Incidentally, if you remember BSD talk/otalk/ntalk/ytalk, you might remember that it divides the screen into two windows and avoids ever scrolling them by wrapping the conversation around from the top to the bottom of the window in a sort of similar way; I suspect that this is because some terminals, like the ADM3A, didn't support scrolling part of the screen, and redrawing half the screen at 2400 baud would have been slow.)

I remember using them around '96, although we had the luxury of 10mbit ethernet (over coax cables) and some vt100 compatible terminal emulators running on amber screen XT machines (on DOS). As you mention neither the adm3a nor the vt52 had partial scrolling. The vt100 did have that and a lot of extra bells and whistles

> But you're running on an FPGA where a lot of circuits can be clocked at 50 MHz, right? 20 ns.

I run them around 50MHz just for the usb serial port, but all the terminal logic works at half that, right around 25Mhz which happens to be the pixel clock at these resolutions, so you cant go any slower than that

> but that still leaves 1000 LUTs for the terminal logic, roughly equivalent to 1000 7400-series TTL chips

I don't think that's a fair equivalence, most 7400 series ttl chips would be several 4 inputs lut, even simple gates like 4x2 bits ORS and way more for things like shift registers and counters of which the terminals have plenty. I also had to deal with ps/2 decoding. On an ADM you can also save a lot of decoding logic taking into account the bit paired keyboard

A couple of years ago I did a vt52 emulator with an fpga, no processor at all (not even a soft-processor). Just regular ram and sequential logic. You can use a simple processor for some commands, but scrolling is best handled in hardware i think:

https://github.com/AndresNavarro82/vt52-fpga

But once you get pretty good at it you can choose to start with a suboptimal word, like a handicap.

It doesn't matter what option he was looking for (maybe nearby share, messaging, etc as shown in a latter image). The point being made is that it wasn't in the first screen and the fact that there were more options (and how to reach them) was not hinted by the interface in any way. Adding to that the expected way of interacting didn't work and only by chance he managed to figure it out.

From the article:

> There's no scrollbar, no handle, no "more" icon, nothing.

...

> I tried swiping it up - that's what I've learned most panels do in Android. But it did nothing. So I gave up.

...

> my thumb slipped transversely (...) The fucking thing was a horizontal slider!

People stay in cities because there are more opportunities there and they have a support network.

I have a property in a very small town around (1000 inhabitants, about 130 kms from the city) and I think it's great: kids can play in the street, I can hear and see horses when I go for a run on dirt roads, nice people, slower living with a close contact with nature. But then again I can work from anywhere and name my price, I have an appartmt in the city and a car and can switch between them as I please.

If you are poor and want to move there it would probably be hell: no much opportunities for a formal job and no one to rely on if you are an outsider... Poor people are not stupid

While I agree with you (having just played a couple of nes games on an original console a couple of hour ago) aren't you missing the point of the quote? This is better than the original in a very specific way: it allows multiplayer on a single monitor. Noone is saying it's better in absolute terms...

> Spreadsheets and FPGAs are two places where there's no focus on a "program counter".

I'll give you spreadsheets, but while it's not the "focus" you will very often see softcores and lots of state machines being used in FPGAs. Some things are just easier to reason about and write that way.

I think you are missing the point. Doing that for one machine for yourself: easy, cheap, maybe even fun. Doing that for 5-10 unknown machines for other people to use in a class... Each may be different, you have to setup each one, they may fail or misbehave at any moment, even during class... Not my idea of easy, cheap or fun. Talking from experience in exactly that kind of situations, working with donated hardware in a school setting.

It's not that easy if everybody is doing it in a different way...

I prefer both control keys next to the space bar, then alt/meta, then super. I have a short spacebar and can do both control and alt with my thumbs. Others prefer an extra control where caps lock is. Others have special keyboards with thumb clusters. Some may use sticky modifiers. And there's even some people that actually like the "normal" layout(!).

I was just thinking about this today. I am currently forcing myself to work on TCL for a small project (I've only used it casually before). Coming from lisp I can appreciate some aspects of it, but it can be frustrating at times.

Why not the other way around? What's the point of using a dual core 32bit with hundreds of K of ram for, let's say, a simple automated irrigation controller? There are applications for both.

> I wholeheartedly agree with all of the above—assuming that you are your own client.

Yes, I was talking from that perspective. Just to remember people that not everything has to be the best possible ever.

> The difference between a car made in 2015 and a car made in 1980 can easily be as dramatic as walking out with superficial injuries—or certain death.

I was replying tongue-in-cheek. This is certainly true, and I appreciate your concern

Sorry I guess I just read too quickly and missed the part about using memories as BIG lookup tables. I am with you on this one.

> Don't crash

That's good advice in any vehicle :)

I think you are missing my point. I only say just because something is available doesn't meant you should use it. Life is not always about minimizing risk, or effort or maximizing productive output.

You can (should) do offsite backups, and even if you don't life doesn't end if you lose some of your work. Not everyone needs to rebuild their setup in milliseconds. If my house burned down my custom configuration would be the last of my worries don't know about you.

But, well. To each their own.

Sometimes people make simple things very complex. As long as he regularly backup his work he could be using an old machine with no issues. Why does he need to backup a vm image, why encrypt it? I imagine you think he should be uploading the encrypted vm image to the cloud... Writers been doing without for centuries. But then again, what do I know... I drive a car made in 1980, a motorcycle from 1962 and use a terminal (vt52 compatible) I made out of an MDA monitor and AT keyboard...

Most fpgas are exactly mini async srams used as LUTs. The old MachXO series I'm working on actually allows using the luts as 16x2 bits RAMS (synchronous, single port or pseudo dual port). It also integrates a d flipflop/latch, a couple of muxes and some carry logic in each cell to give a little more power/flexibility, but the main architecture is sram luts, flipflops and giant muxes at each input to do the routing

Actually more than one, and new projects are started everyday to RE more architectures as we gathertools and knowledge from previous efforts. While the newer higher end fpgas are still out of reach a Lattice ECP5 can do pciE, gigabit ethernet, hdmi, ddr3, usb3, and of course has more than enough for a RISC-V (as a matter of fact you can fo one in a much cheaper/smaller ice40: https://github.com/cliffordwolf/picorv32

Ah, totally forgot about these. My father saw them extensively in x-ray generators (which may reach over 100KV for some applications...)

As a matter of fact you can do it with just one... That would be a half wave rectifier (not that good, you miss half the cycle). You can also do full wave with just two, but you need a center tap on your transformer. I remember finding both of these in early guitar tube amplifiers schematics (those early ones used vacuum tubes for everything: rectification, pre-amp & power).

What I took from the article is that it's useful when combined with type inference. So in Zig you could do:

  var x : u8 = 5;
  var y = @as(u32, x);

OR

  var x : u8 = 5;
  var y : u32 = x;

The cast is needed in the first case to force the inference y: u32, otherwise it would be y: u8

Yes, but it could also be a single program with commands. I think Jeff Raskin talked about something like this with Archy. You could also think about the emacs paradigm extended to non-textual objects (to me emacs is like a lisp machine tuned to work with text)

or the lisp machines

Adding the numbers is not the problem, the problem is what the numbers represent, where do they come from (if they come from only one place...) where and for what are they needed.

Quickly you have to consider different kinds of numeral systems, bases, decimal separators (which may be locale dependant), precision, units, the difference in adding time (or dates), or money in different currencies (with and without different kind of taxes), etc, etc, etc.

Sure most of the times you can abstract yourself from all this, use sensible defaults, whatever, but that complexity is still there and sooner or later it will get you, even if you try to hide it under the rug...

Great I will check it out! I got interested in the ATARI ST when I read about the VT52 extensions in the Wikipedia and I wanted to try 4 bits color for foreground/background and palettes.

I have this hardcoded to 9600bps but it should be able to do up to 115200 with no problem.

I really want to explore the space of modest processor with custom chips like Commodore & Atari did on their 8bit and 16 bits systems. I find it way more interesting/fun than the ultimately successful superscalar/big cache/big gpu that we ended up with, and fpgas make it very easy to test things out.

1. It uses two clocks, both derived from the PLL from an onboard 16Mhz MEMs oscillator: 48Mhz for usb (the usb<->serial bridge is implemented in the fpga fabric) and 24Mhz for the vga pixel clock (25.175 would be the 640x400@70Hz standard, but I compromised by dividing the usb clock by two). Using a usb<->3.3v serial cable or an fpga board w/external usb<->serial bridge you could run everything @25.175Mhz (and save half the logic in the FPGA and a kB or embedded RAM).

2. I will have to measure this and get back to you, but can't be too much, and negligible compared to the monitor in any case.

I can tell you that it's powered by a USB port and has onboard 3.3V & 1.2V regulators (300 mA & 150 mA max respectively). It doesn't currently implement a standby mode, but for reference the FPGA supports a standby mode which comsumes about 21uA according to the datasheet.

Yeah, the vt52 had a very primitive special purpose processor. The ADM-3A (which is even simpler) was in fact implemented with off-the-shelf ttl chips and sram (but only had escapes for cursor position, and clear whole screen).

Given the HDL languages and cheap FPGAs we have today it is possible to do more with just FSMs and the icluded RAM/ROM, compared to using individual ttl/cmos parts and designing a PCB. I mean you could do a VT100 compatible if you really wanted, but doing it with an 8 bit micro is way easier to write & debug (and extend!).

Author here. Guess someone crossposted from reddit or the tinyfpga forums. This is just a side project I did while practicing Verilog but it works fine as a serial terminal for my linux box, to do shell & emacs stuff. Glad to answer questions if anybody has them

That's what I came here to say. I can't believe the use of the compose key isn't more common. I just remap caps lock (which I don't like) to compose and kill two birds with one stone...