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Epson PX-8 Oval Display Adaptor

Nice to see some people are still interested in this project. It more or less stalled. All components and the board arrived, and are stored in a box labeled "Oval UD-80" waiting for assembly and testing. Then other projects took over.
Maybe the coming winter season for this hemisphere might see some progress for projects in this stage. Starting something is easy, finishing is much harder. It does happen, occasionally.

Greetings,

Fred Jan
 
Nice to see some people are still interested in this project. It more or less stalled. All components and the board arrived, and are stored in a box labeled "Oval UD-80" waiting for assembly and testing. Then other projects took over.
Maybe the coming winter season for this hemisphere might see some progress for projects in this stage. Starting something is easy, finishing is much harder. It does happen, occasionally.

Greetings,

Fred Jan
I know the feeling. I have so many projects (Amiga 2000 faulty RAM board, PX-8 batteries and RAM board, Cifer faulty hard disk, Torch Triple X power supply etc etc) and so little time...

It's awesome you have a board ready for assembly. When you get back to it, let me know if you need any more photos of the original. 👍
 
Nice to see some people are still interested in this project. It more or less stalled. All components and the board arrived, and are stored in a box labeled "Oval UD-80" waiting for assembly and testing. Then other projects took over.
Maybe the coming winter season for this hemisphere might see some progress for projects in this stage. Starting something is easy, finishing is much harder. It does happen, occasionally.

Greetings,

Fred Jan
Yeah I know that all too well. I also have a pile of things to do/finish at some point.

When you do get back to working on it keep us posted. I'd definitely like to eventually be able to use the PX-8 with an external monitor.
 
The board wasn't quite stable, it just stopped working without me helping. The EPROM probably didn't like its /PGM pin being tied low. With a new EPROM I managed to come closer to a working external screen for the PX-8 (and later the PX-4). The info in what happened in more detail is at https://electrickery.nl/comp/px8/UD-80_blog/. Eventually a new PCB is now on the horizon, now it actually seems to work. MC6803/HD6303 and EF9345 chips are still available online...

The realization this is not a EPSP device like the external floppy drives, but more of a half-terminal (only the display side, not the keyboard) was new to me.

Greetings,

Fred Jan
 
Here a virtual christmas present of how the replica pcb could look. I'll wait with routing until the DIN chassis connectors arrive for the proper dimensions before making the PCB design.
This is the time for remarks or suggestions; I'm thinking to replace the 8-pin DIN with a 9-pin Dsub and maybe a USB type power connector instead of the barrel-jack. Power consumption is well below 500mA, so a standard phone charger could be used.
Greetings & happy chrismas,
Fred Jan
 

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Here a virtual christmas present of how the replica pcb could look. I'll wait with routing until the DIN chassis connectors arrive for the proper dimensions before making the PCB design.
This is the time for remarks or suggestions; I'm thinking to replace the 8-pin DIN with a 9-pin Dsub and maybe a USB type power connector instead of the barrel-jack. Power consumption is well below 500mA, so a standard phone charger could be used.
Greetings & happy chrismas,
Fred Jan
Happy Christmas! 🌲☃️
 
Here a virtual christmas present of how the replica pcb could look. I'll wait with routing until the DIN chassis connectors arrive for the proper dimensions before making the PCB design.
This is the time for remarks or suggestions; I'm thinking to replace the 8-pin DIN with a 9-pin Dsub and maybe a USB type power connector instead of the barrel-jack. Power consumption is well below 500mA, so a standard phone charger could be used.
Greetings & happy chrismas,
Fred Jan
Looks nice.

Yeah it might be nice to use a standard 9 pin d-sub for the serial connection. Whats the unpopulated footprint right below SW3 on the right side of the board?
 
Whats the unpopulated footprint right below SW3 on the right side of the board?
That is the gray-level composite output using a RCA-plug. The EF9345 has RGB outputs (via the 6-pin DIN connector) but I am not sure color is usable from the PX-8 or PX-4. Maybe via escape codes?
Lacking the manual, the only way to find out is disassembling the firmware.

Another interesting aspect of the UD-80 to be investigated is the difference with the usage of STAT CON:=TTY: (https://electrickery.nl/comp/px8/funWithSTAT.txt).
 
Components are in, the boards are routed and ordered. Expect them in some weeks.

@Crashedfiesta: can you make a photo showing the front of the original UD-80? It would look nice on a hackaday project page I am preparing.

Exciting stuff! I shall try and get out there tonight. 😁
 
Sent some pics over email but added them here too. Not sure if the forums will 'downgrade' the resolution.

Let me know if you need any more! :)
 

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Speaking of display, did anyone ever manage to open the display of a PX8 ?
I tried but it looks like it's gonna break. I'd like to check what's inside (capacitors, etc) and also deoxit the contrast thing
 
Speaking of display, did anyone ever manage to open the display of a PX8 ?
I tried but it looks like it's gonna break. I'd like to check what's inside (capacitors, etc) and also deoxit the contrast thing
Yes, I did. It requires removal of the front "PX-8" label which is glued to the display part and very hard to remove without bending.
 
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