anyone here into retro computing

[AmpleApricots]

EF9345P

I found out what this chip was usually used in, in Minitel Terminals! Well, that explains a lot. In these it was used in combination with a 8052. (microcontroller, a whopping 256 bytes of RAM, they were not fun) I wonder if it would make sense to combine the chip with an arduino and actually build a VT-100 terminal, I feel that could be quite handy. Even though weird, instead of using the signal with something like RGB2HDMI in the end, you might as well use the Pi zero directly to pretend to be an ANSI terminal (not some Linux software, bare metal)

It all kinda reminded me of Teletext, and I have some teletext IC circuity around here somewhere. Teletext is still used in germany. I'm not sure if the US has something similar. Here is a website where you can see the currently sent Teletext of some german private TV stations. (spoiler: It's all phone sex ads for boomers, you might find character art of naked women)

 

[Jump]

VT-100 terminal,

I think VT-100 means 80x25 which I don't think is going to look good with that chip.

In the USA teletext was called Videotex and it was just a flash in the pan in the very early 1980s. CompuServe supported it and a few of the 8bits had support for it but things moved fast to the BBS's and PC with ANSI.


I have a RC2014 with the pico VGA terminal card. I used it for for a bit until I found a real WYSE dumb terminal at a hamfest and now just use the SIO/2 serial tty card which is what CPM is most happy with.

I always found those early video chips like your EF934P interesting. I saw this blog post about bringing up a MC6847 and ordered a few from China. I have Grant's simple 6809 computer design built on a breadboard and I am going to see what I can make happen by sticking the 6847 on it's bus.

 

[AmpleApricots]

look good with that chip

6x10 pixels per character according to the datasheet. Bit thin, but might be fine, we will see. There is a bit of similarity to some of the earlier high resolution mode EGA fonts. I was actually considering using a Hercules or EGA chipset but didn't feel good about slaughtering an ISA card. I'm going to whip something up quick to see what it looks like, I've read the handbook a bit more and it's a bit weird to program. I have various video chips from that era, mostly recovered from junk. Quite a few teletext chipsets, They would also be fine to use if you're happy with 40 width, I couldn't even find the datasheets of many of them though and you usually need at least two custom ICs in these circuits so the likeliness of me ever using them for anything is pretty low. I also have other video chips, a few TMS ones and the V99x8, uDP7720 and a few others. The EF934P isn't really even close to being the best of the bunch but this isn't really about using the best, isn't it? And I agree, video stuff of that era is fascinating. Compared to modern tech it's primitive but also feels sophisticated and complex at the same time and everyone thought of their own ways to do things, within the (considerate) limits of the technology.

RC2014

I have a self-built Z180 based system directly running my own version of Forth bare metal. The chip is speedy and has two inbuilt serial ports, an MMU, some timers, dma and other luxury while still being "vintage". (the Z180 actually has an interesting history, it was originally designed by Hitachi, not Zilog) My long-running project is to write a bare metal, Forth based OS, the Z80 architecture isn't quite ideal for Forth but it is an easy to get (both buy and understand) family. In future incarnations of this computer I'll implement the RC2014 bus, if I don't just buy one off the shelf one that is. (or go 16 bit) I have 512kb of RAM and a 512kb flash ROM (the Z180 can address up to 1 MB and use up to 64kb at once) the flash ROM is theoretically rewriteable from inside Forth and I could get away with a lot less ROM but this was easy to wire up and I had the parts. The Z180 running at 18 MHz comes with it's own set of problems as you have to insert wait states for IO as most of the hardware like the EF934P usually can't handle the speeds. An 8 bitter will always be an 8 bitter and never be incredibly useful (honestly, computers being useful as a general puprose thing starts in the 16-bit range IMO, I could well imagine using the Amiga for day to day stuff even today, a speccy or C64 though? Eh) but it is in this comfortable range where it is very easy to understand the entire system and just rewrite your primitive OS in an afternoon. There are also all these discrete and odd special ICs with special functions you can screw around with without it feeling out of place in context of the rest of the system, which is always fun. The Z180 also has amenities to build a multiprocessor system with which interested me with Forth, but I'm not sure that's ever actually going to happen.

pico VGA terminal card

I just use xterm with one of these FTDI dongles. It has very comprehensive VT terminal support, and also ReGIS and Sixels. Since my thinkpad convertible has a nice, small 3:2 screen I can set a pixel font exactly to fill the entire screen at 80x25 without looking too big, put a nice mech keyboard in front and have an impromptu terminal. This is still not an ideal solution and I would like to have a proper dumb terminal eventually, I just can't deal with these old CRTs anymore and would like something slightly different (eInk perhaps?) in an attractive package.

ordered a few from China

Let me know how it goes. The chinese once sold me a MOS 6802 IC with a lasered datecode of 2014. It actually still worked, they just somehow felt the need to reprint it in a very ugly and fake looking way, which is a godamn shame. That 6802 was also a sygnetics part, as a stamp on the bottom told me. I still got a working 6802 in the end and I have no idea what this even was about. It's like they have a compulsive need to fake things.

 

[Jump]

Let me know how it goes. The chinese once sold me a MOS 6802 IC with a lasered datecode of 2014. It actually still worked, they just somehow felt the need to reprint it in a very ugly and fake looking way, which is a godamn shame. That 6802 was also a sygnetics part, as a stamp on the bottom told me. I still got a working 6802 in the end and I have no idea what this even was about. It's like they have a compulsive need to fake things.

I am 100% expecting these chips to be blacktopped. They all seem to do it when your in the 5pcs for $10 range.
They strip boards with blowtorches and knock the chips out. Sort them by chip type, sand the tops off them, blacktop them, then laser etch a common number on them. It's super annoying because you lose information that may matter like speed ratings. Or with stuff like the 6809 the suffix really matters . I got a 5pc lot. 3 where 6809 and 2 where the 6809E which is the external clock version. All laser etched with the same common part number and date code. The vendor made good on it after I contacted him so he ended up making nothing on the deal.
Its all bullshit. They know they arn't fooling anyone with the chips being NOS. And the buyers know they are rolling the dice getting 5 reclaimed chips for 10 bux. So why even waste the time faking the markings?

 

[AmpleApricots]

waste the time faking the markings

Think it started when they started figuring out that some ICs that 'seem the same' (from an outside perspective) are more sought after than others and then it just organically evolved from there to become a part of the process. I don't get it either. To be fair, they are basically recycling e-waste over there, so the hardware they pulled this out of was probably just a heap of garbage and cockroach housing in some storage unit at some point, and the ICs probably looked the part - corroded pins, scruffed and scratched casings, the works. Maybe a way to make them more presentable and sell them in a "standardized quality"? I honestly have no idea. It doesn't feel like it should be worth the effort. I mostly don't need such old custom ICs so I don't really order anything like this from china, but I wanted a bunch of SRAM then and this discouraged me to get it because god knows what actual ratings (and sizes) I'd actually get. It's not worth my time figuring that out, so I paid for locally sourced which was kind of a rip off tbh.

 

[Apis Mellifica]

I used to collect old computers. I have two Macintosh Plus computers and a Commodore 64. The Commodore still works, I bought a 64NIC+ card for it to connect to the internet, and it worked pretty good. Only one of my Macintosh Plus computers worked until recently when the working example's screen failed. I don't really have the drive to repair it, so now they both sit as decoration. Eventually I want to gut one of them and install a Raspberry Pi running BasilliskOS to simulate the software without abusing real hardware.

 

[AmpleApricots]

EF9345P

This is such a bewilderingly strange chip. It's multiplexing data and address bus lines, that's not really strange and I can see why, seeing it was supposed to be easily used with weak MCUs that also wouldn't have a lot of pins to spare but it made hooking it up a bit more difficult because all the logic for that task I have lying around is already bespoke for other projects and I didn't want to buy anything. I actually ended up programming a GAL and I got it easily hooked up to some SRAM, but oh god the programming and the borderline incomprehensible datasheet. (I found some errors I wouldn't have figured that quickly without googling) I don't really even understand how you are supposed to do 40 column mode correctly yet. The memory layout is super odd. I hooked it up directly to the OSSC for now (resistors) but yeah, works. Looks fine actually. With enough memory (on the side of the controller, and we are talking pittances of memory here) the character set is extendable with a ton of custom characters. This is a good chip if you want to build a terminal with minimal parts and effort on the side of the system talking to the chip and I guess that is what it was for, after all. If you don't want to delve into the arcane of classic MCUs you could hook this up to a small arduino which you could hook a ps/2 keyboard and serial port to. If you have a SCART CRT-TV the RGB output of the chip would make it very easy to build a weird, modernish CRT TV terminal. I mean this would probably be easier with two arduinos but whatever.

I saw some of these from local (EU), non-chinese sellers for very cheap and ended up picking some spares and the whole Thomson product line of 80s graphics ICs up. I usually try not to hoard in modern times but I made the repeated experience in the last few years that stuff sometimes is available until it just isn't and I wanna play around with them a bit more down the road. The later versions are proper graphics ICs and one of them actually seems quite cool (on paper). We will see.

 

[Enig]

It is now May and there is still no word on a v2analog card for the IIGS. Why does getting good video out of a IIGS have to be so fucking cursed, I just want a crisp display not having to use a blurry supergun upscaler or a component video TV.

 

[George Lucas]

I’m actually a big proponent of emulation and not hoarding old hardware, for moralfag purposes. Hoarding hardware creates clutter and requires a lot of time and energy to keep things in good working order and organized. However, I recognize that certain things need to be preserved, like peripherals. So I hold onto controllers and cables. Otherwise I have very little of my old hardware sitting around.

Emulation allows poor people and the unfortunate access to these old programs. By ensuring accurate emulation, we can preserve not only the software but also the hardware’s behavior for future generations to use and observe. I strongly despise the commercialization of ‘retro’ that’s become so commonplace in the scene the last several years.

 

[Jump]

It's multiplexing data and address bus lines,

Jesus thats complicated

The MC6847 is so much simpler. In its most basic mode it just counts out on the address pins to scan up memory and displays what it gets back in on it's data pins. Im thinking I can just feed it's data pins with arduino.

 

[AmpleApricots]

Jesus thats complicated

The GAL was overkill and you can also do this with some 74xx logic but it was the simpler solution and also the solution that made me have to do less wiring on the breadboard. The Z(1)80 is different from e.g. the 6809 or the 68k and more like the 8086 in regards that I/O and memory space are a distinct thing. That at least in theory allows you to address a ton of I/O devices without reducing the effective amount of memory the chip can address or having to resort to tricks like banking and you get a bunch of extra signals to boot so the decoding is also less complicated. In practice that address space is only 8 bit wide though so you often end up using several addresses for the same device and it can also make addressing of devices with a 16 bit wide anything a little bit more complicated and slower. So in regards to hooking it up to the Z180, the scheme this chip uses kinda suit me well.

The MC6847 is simpler to use because it's also a simpler device that does less and needs more external circuity and work by the processor of the system. For example, the EF9345P uses it's memory all by itself and just recieves commands by the bus master. It's purpose wasn't really to be super multi purpose but to be a low cost, highly integrated chip that does terminals with an MCU (no proper CPU, we don't wanna pay for more RAM than we absolutely have to and we also don't want to pay for an UART) that could just about handle a modem, keyboard I/O and firing off some instructions to the EF9345P and didn't have time (or program memory) for much else.

That said, yeah it is kinda overtly complicated. This actually made me explore some and there are quite a few different graphics chips in that era I never heard of, some with quite impressive stats like 1024x512 resolution or Amiga-like color palettes. (The more high end ones are better suited for 32/16 bit CPUs like the 68k) That they re not widely talked about probably has reasons, they were either expensive and rare, impractical to use in a general purpose way or they otherwise sucked for the end user. There's reasons everyone knows the C64 and less have heard of the Matra Alice 32 or Philips VG5000. (both actual computers employing the EF9345P as graphics processor)

 

[TheBigZee]

I've done a lot of cool stuff with the z80, z180, and nec v20. Unfortunately I can't share exactly what w/o doxxing myself.

I've got an unreleased design that can run quickbasic w/a self made pico MDA so long as you avoid certain functions. I've got an unmade design for an 80c286 based "super" turbo xt (the FFFF segment maps to FF). It uses a modified version of sergei's xt bios.

I've stopped working on them. I spent about two months working through philosophy to figure out what makes the "soul" of a retro system. My end conclusion: Emulation is as "real" as a retro system without a vintage CRT and peripherals.

I'm working on emulation related projects now, but again - can't share them.

 

[XYZpdq Jr.]

I’m actually a big proponent of emulation and not hoarding old hardware, for moralfag purposes. Hoarding hardware creates clutter and requires a lot of time and energy to keep things in good working order and organized. However, I recognize that certain things need to be preserved, like peripherals. So I hold onto controllers and cables. Otherwise I have very little of my old hardware sitting around.

Emulation allows poor people and the unfortunate access to these old programs. By ensuring accurate emulation, we can preserve not only the software but also the hardware’s behavior for future generations to use and observe. I strongly despise the commercialization of ‘retro’ that’s become so commonplace in the scene the last several years.

yeah having the ancient hardware (and the appropriate half-dozen CRT monitors) is really cool
until you have to move

 

[CantankerousStegosaurus]

As a retro collector myself, there is nothing I would like more than to throw each and every one of them in the trash. It's fucked, mate.

 

[Annoying Orange]

I don't use or collect old computers, I haven't even used Windows 98 since 2007 but I do like reading PC magazines from the 1970s and 1980s. PC Mag and BYTE Magazine are worth archiving if you're interested.

 

[DavidS877]

I don't use or collect old computers, I haven't even used Windows 98 since 2007 but I do like reading PC magazines from the 1970s and 1980s. PC Mag and BYTE Magazine are worth archiving if you're interested.

TOSEC-PIX should also have most of the common ones.

https://archive.org/search?query=TOSEC+PIX&sort=-publicdate

 

[AmpleApricots]

Through libDVI the Pi Pico 1 (RP2040) is capable of putting out a digital DVI signal by basically brute-forcing it. That signal is slightly out of spec but from all I read, it usually works well. The other day I found VersaTerm which is a serial terminal that can output to DVI/HDMI and accepts a usb keyboard as input, all through the Pi Pico. There's a similar project, pigfx, which uses a regular Pi Zero or Rasperry Pi bare metal and is obviously more powerful, but somehow doesn't feel as polished.

Now VersaTerm has a custom PCB with lots of additional parts and you know how it is with these, having the PCB made is five bucks and then you drop fifty on getting all the components together. Also I'm not exactly wild about that board layout and it's size. Somebody made a fork where you can use versaterm with the RP2040-PiZero, which is a RP2040 with the footprint and connectors of the Pi zero. (This is the official waveshare one, but you can find clones of it all over aliexpress for about ten bucks) So for basically ten bucks, you can turn any old LCD into a vt100 color serial terminal (and add a proper RS232 via hat) and if you like fancy mechanical keyboards which usually are exclusively USB, they'll work with it. The interesting thing with VersaTerm is that it also works via USB ACM, So you can hook up the USB C power port of the RP2040-PiZero to your modern *nix systems USB port and use it as serial terminal for that computer, too.

Of course neither of these two solutions offer the same versatility as e.g. a bog standard Linux system with terminal emulator and something like minicom, but it's quite cool if you don't have an actual Terminal from back in the day laying around but still want to use some serial-based system (mostly CP/M systems and some interesting one-chip solutions) without having a whole-ass PC in between.

The neo6502 by omilex works in a similar way, although the RP2040 there does a little more, up to and including being the RAM for the 65C02. (That's why "neo", the CPU is basically "living in the Matrix" with everything simulated via the Pico, so to speak) Design-wise, I find the neo to be the more sound than the argon who does a similar thing with an Esp32, although less elegant. Of course with both you could argue that it's pointless to anchor such slow and ancient processors to something like the Pico who'd do just fine doing everything by itself.

 

[Squishie PP]

I have a similar hobby, but with stuff that is around 15+ years old instead. Still somewhat nostalgic, yet I can still use them for practical purposes.

 

[AmpleApricots]

I got emacs 19.25 (full emacs, not micro emacs the amiga comes with) running on my 28 Mhz SEC 68k A600. It's not nearly as "batteries included" as current emacs 29 is but it pretty much works the same and doesn't run that badly. (If you don't mind occasional few-second pauses for garbage collection or command completion) It even has arexx integration. This would be a good reason to have a processor that's somewhat faster and maybe has a cache, vs. this particular pick of mine. On an old school 030/50 Mhz accelerator or a newer-school 020/030 33 Mhz one with fast, modern RAM it'd probably actually be a pretty good experience, if you pick your elisp extensions carefully.

 

[Belisarius Cawl]

I got emacs 19.25 (full emacs, not micro emacs the amiga comes with) running on my 28 Mhz SEC 68k A600. It's not nearly as "batteries included" as current emacs 29 is but it pretty much works the same and doesn't run that badly. (If you don't mind occasional few-second pauses for garbage collection or command completion) It even has arexx integration. This would be a good reason to have a processor that's somewhat faster and maybe has a cache, vs. this particular pick of mine. On an old school 030/50 Mhz accelerator or a newer-school 020/030 33 Mhz one with fast, modern RAM it'd probably actually be a pretty good experience, if you pick your elisp extensions carefully.

What does your dotfile setup or whatever (Vimfag here plus I haven't used Amiga in a while) look like in that instance?

On a related note, here's a screenshot of me using Workbench 3.1 in 2017 with a high-fidelity PNG background. Hopefully my notes are adequate to get that kind of performance again one day.