RC2014 80 column card

[Alan Cox]

I've posted the initial pieces for this to hackaday.

It uses an EF9345 as a retro-appropriate video chip (apparently the
one used in the French Minitel) to provide RGBI output with separate
or combined sync pulses. That will drive an upscaler or SCART input
with a few resistors and can also trivially be used to produce mono
composite (not a good idea for 80 columns) or Svideo.

Software at the moment consists of typing hex incantations into the
ROMWBW monitor command, but that will be the next job.

The video output is really sharp as you'd expect from a digital out.

https://hackaday.io/project/189225-rc-2014-80-column-video

[Mark T]

Did you find a good source for the EF9345? Utsource are only showing used parts.

Does it work with a VGA monitor?

The z80 interface from the application note is interesting. I wonder if there is some reason to use a gate to combine /RD and /WR instead of using /M1. Maybe some concern of short glitches at the beginning of a write cycle if there is a slight delay from /IORQ to /WR. Could also be just that the /M1 might not be available and they already have the gate to hold AS high during reset to make sure the EF9345 is in intel mode after reset.

[Alan Cox]

On Wed, 18 Jan 2023 at 19:21, Mark T <mark...@gmail.com> wrote:
>
>
> Did you find a good source for the EF9345? Utsource are only showing used parts.

Not seen any new ones, but used by the bucket load (scavenged off all
those minitel terminals I guess)

> Does it work with a VGA monitor?

With an upscaler.. It generates PAL or NTSC timings so unless your
monitor can do them it'll fail. If you rmonitor can then you'd just
need to drop the voltage levels. Mine is currently running into a
scart or into an upscaler.

Alan

[Mark T]

I’ve been looking for a simple 80 column text display. So I ordered a few on Aliexpress, they say new and original but I guess I’ll find out when/if they eventually arrive, Chinese new year is not the best time to place an order. Hopefully I can just quickly connect a clock and check for activity on the video memory before building a full module.

[Phil G]

I've used variants of Geoff Graham's PIC terminal in several projects, its cheap and works perfectly.

I dont generally use the full thing, just a subset based on the lower (much simpler) diagram:

https://geoffg.net/terminal.html

[Alan Cox]

On Wed, 25 Jan 2023 at 20:08, Mark T <mark...@gmail.com> wrote:
>
> I’ve been looking for a simple 80 column text display. So I ordered a few on Aliexpress, they say new and original but I guess I’ll find out when/if they eventually arrive, Chinese new year is not the best time to place an order. Hopefully I can just quickly connect a clock and check for activity on the video memory before building a full module.

Whilst the character access side is demented the video side is nice.
If you power it up and add a clock you get PAL with split clocks
before you touch the device. It can only produce PAL or NTSC with
composite or separate clocks so that is one of the usual "why is my
video card not working" nightmares it avoids.

[Alan Cox]

On Wed, 25 Jan 2023 at 20:08, Mark T <mark...@gmail.com> wrote:
>

> I’ve been looking for a simple 80 column text display. So I ordered a few on Aliexpress, they say new and original but I guess I’ll find out when/if they eventually arrive, Chinese new year is not the best time to place an order. Hopefully I can just quickly connect a clock and check for activity on the video memory before building a full module.

If you want me to post you one of the spare PCBs (if I can find them I
think I know where they are 8)) then drop me a note off list

[Mark T]

Hi Alan, thanks for the offer but I’m in Canada so probably not worth the extra postage. I’ll probably use a skinny dip ram anyway as I have quite a few on hand.

Mark

[Mark T]

Received the EF9345 from Aliexpress, quite good condition but doubt they are new as advertised. No indication of socket marks on the pins, but look like they may have been soldered and then cleaned. All have different date codes and differences in markings which is probably a good sign as remarked parts are likely to be identical on top with different mould marks on the bottom. Date codes in the range 8802 to 8950 which seems about right.

Powered one up with sync input grounded, 0 v and 5v, approx 2.2v on all pins with 12MHz clock on pin 12. I see activity on vram OE and ASM, and also what looks like blanking on R, G and B, but no activity on address or data interface to vram, but that might need some software initialisation. 

I think its probably worth the effort to connect memory and an interface.

[Mark T]

Found this schematic for the VG5000, french site but can select english translation.

https://forum.system-cfg.com/viewtopic.php?f=7&t=9245&start=30

Interesting that they don’t use a nand gate for AS.

I might copy the use of open collector buffers for the RGB output.

[MartinR]

This looks like an interesting circuit. Does anyone know if a PCB was ever made available? Either as a physical board or as Gerbers. My Googling has come up with nothing.

[7alken]

hi Alan, I just reviewed after years you hackaday and found EF9345 is using that 5x7 characters by default and in 40chars mode also UDS - as you wrote it is crazy inside, but do you have still some PCBs for the RC2014 card? I found that appnote, wanna try it also, in fact would be cool for me to have "some" unified interface to text mode, accelerated where possible or rendered to framebuffer elsewhere at least... its all still about those 5x7 char like on QL (love) .. ))
thanks
Petr

[Alan Cox]

On Sat, 20 Sept 2025 at 19:22, 7alken <antos...@gmail.com> wrote:

hi Alan, I just reviewed after years you hackaday and found EF9345 is using that 5x7 characters by default and in 40chars mode also UDS - as you wrote it is crazy inside, but do you have still some PCBs for the RC2014 card? I found that appnote, wanna try it also, in fact would be cool for me to have "some" unified interface to text mode, accelerated where possible or rendered to framebuffer elsewhere at least... its all still about those 5x7 char like on QL (love) .. ))

Will see if I can find the spares. It's a very very strange chip. Even the UDS is strange as you can have characters mixed in that are chunky but four colour. Even crazier though is the way they encode the four colour choices from all 8 into a single byte such that you can pick any four.

That one ought to be set as a question for job interviews ;)

Alan

[7alken]

Thanks Alan, ya, I just found some minitel(2) videos on youtube, its in fact 8x10 raster and there are horizontal spaces quite big for 5x7 sadly, but I found you have this also in EmulatorKit with tms9918 too, nice; that QL renders probably in raster 6x9 or 6x10 ... I know this is not nice for chips )) .. so it is hard thing )) ... if you find the PCB or can share the design, will be glad to try to build it :-) btw, I now seeked also for PLCC44 version, something is probably somewhere, but for TS9347 its like only DIP40 version existed? can't imagine also the PLCC versins are not so much on ebay, they were not used much? or soldered? not in sockets? 
Petr

[MartinR]

I have a couple of EF9345P 40pin DIP chips and would be interested if PCBs or design files for RC2014 were made available.

Many thanks -

MartinR

[7alken]

ya, pls Alan, I just rechecked if I am not blind, but there is really only components list and schematic, gerbers files are missing;
https://hackaday.io/project/189225/components
P.

[Alan Cox]

On Sun, 21 Sept 2025 at 11:44, 7alken <antos...@gmail.com> wrote:

ya, pls Alan, I just rechecked if I am not blind, but there is really only components list and schematic, gerbers files are missing;
https://hackaday.io/project/189225/components

Uploaded the kicad files from my archive. I don't have a saved copy of the gerbers but this is them regenerated

 

[MartinR]

That's really great! Much appreciated - very many thanks.

[7alken]

thanks a lot Alan :-)

[7alken]

btw, MartinR, are you from EU or nearby to share some PCB order? or if this will be more complicated?? (if Alan has no spares or is complicated searching, I can imagine that)
Petr

[MartinR]

Hi Petr - I checked with JLCPCB and they were charging $3.50 for manufacture, including shipping. I don't understand how they can do it for that price, so I have ordered. And it also saves Alan hunting. I could share, depending on postage costs. I live in UK. Where do you live? Please email me directly if you're interested.

[Alan Cox]

On Mon, 22 Sept 2025 at 07:40, MartinR <marti...@gmail.com> wrote:

Hi Petr - I checked with JLCPCB and they were charging $3.50 for manufacture, including shipping. I don't understand how they can do it for that price

There's a youtube tour of their plant. They can do it because they have enormous volume and massive automation. The number of human interactions with stuff you see in their tour is tiny.