[HN Gopher] Adam74: A terminal for a small 8-bit computer
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       Adam74: A terminal for a small 8-bit computer
        
       Author : chmaynard
       Score  : 120 points
       Date   : 2022-08-21 22:28 UTC (1 days ago)
        
 (HTM) web link (www.engineersneedart.com)
 (TXT) w3m dump (www.engineersneedart.com)
        
       | mogery wrote:
       | Really, using a Teensy 4.0 to make scrolling faster? That seems
       | really overkill to me. You could make a small computer out of a
       | Teensy 4, quite excessive to use it as a display-out.
        
         | [deleted]
        
         | hypertele-Xii wrote:
         | Computers are getting cheaper faster than we can figure out
         | what to do with them.
         | 
         | Overkill is fine.
        
         | [deleted]
        
         | HeyLaughingBoy wrote:
         | [shrug]
         | 
         | I will happily use an entire arduino clone to produce a
         | periodic pulse when it could be done with an NE555 timer. One
         | will take me approximately 2 minutes, the other more than 2
         | hours.
         | 
         | When your build quantity == one, the concept of overkill
         | becomes less meaningful.
        
         | JKCalhoun wrote:
         | That's true. If I had been able to get the hardware scrolling
         | to work on the ILI9341 no doubt it could have easily run on a
         | lower-end Teensy. Maybe someone more clever than me can get it
         | to work. It sucks to resort to brute force.
        
           | hedgehog wrote:
           | I'm a little surprised there's not a better LCD controller
           | for this kind of application, even a little iCE40 should be
           | enough to implement a character display and smooth scrolling
           | on both axes.
        
         | kragen wrote:
         | Vast overkill in this respect is historically accurate; the
         | VT100 was built around an 8085, for example.
        
           | bitwize wrote:
           | The 8008 was invented for a terminal application -- the
           | Datapoint 2200. So not only were VDTs effectively
           | microcomputers since the 70s, but Intel's main processor line
           | up until the present day owes its existence to VDT
           | applications.
        
             | kragen wrote:
             | Yeah, but the Datapoint 2200 was kind of a high-end niche
             | thing, I think. I've never seen one in real life. (And I
             | don't think anyone ever actually built a terminal around an
             | 8008.) The VT100, by contrast, was ubiquitous. It also came
             | out in the 01970s: 01970 for the 2200, 01978 for the VT100.
             | Early-01970s terminals like the ADM3A or the Tek 4014 more
             | typically were not microcomputers at all, just discrete
             | logic.
             | 
             | The VT52, with a much richer escape sequence language than
             | the ADM3A, was kind of on the borderline:
             | https://vt100.net/docs/vt52-mm/chapter4.html
             | http://xahlee.info/kbd/iold51593/EK-
             | VT52-MM-002_maint_Jul78_... It had a "microprogram" in ROM
             | with conditional jumps, but lacked capabilities like
             | arithmetic, bitwise operations, and subroutines that could
             | be called from more than one place; many of the
             | instructions are things like "start printer" and "jump if
             | UART has received a character".
        
               | AndresNavarro wrote:
               | 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
        
       | TedDoesntTalk wrote:
       | I had a Lear ADM-3A dumb terminal and some TeleVideo clones (912
       | and 912c) that I acquired right before the pandemic. The cases
       | are beautiful 70s works of art. Intended to connect to Raspberry
       | pi's but never got around to it.
        
         | kragen wrote:
         | It's easy to do, and you'll be pleased to know that
         | termcap/terminfo supports them, so you can use almost all your
         | usual terminal programs with them. If you run into the
         | occasional exception, you can run it in screen(1), which
         | emulates a VT100-family terminal using terminfo.
        
           | jandrese wrote:
           | For once carrying around that huge database of decades
           | obsolete terminal quirks pays off.
        
         | Gordonjcp wrote:
         | I rescued a couple of ADM-3A terminals from RGIT many many
         | years ago (like 30 or so) and found they contained the optional
         | lowercase ROMs *and* a board with a 6809, a 6845 and a bunch of
         | RAM as well as a few other things to allow it to emulate a Tek
         | 4016 "storage 'scope" terminal.
        
       | jdblair wrote:
       | Bravo to nicely designed gadget.
        
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       (page generated 2022-08-22 23:02 UTC)