Yeah, finally, a VT55 in my collection

[Schroeder]

It was listed for Euro 99,- at ebay Germany. Missing some keys. Fixed it temporarily with VT100 keys in the top row and moving some to the main keyboard.

I know, many of you have one possible in their collection, it is maybe not that rare, but anyway, this is my first VT5x series Terminal. Super happy!

Now it needs some cleaning and maybe some fixes. The rubber in the printer bay does not look good either.

 

[MattisLind]

I have a VT55 that I need to spend some time on. Do you have the schematic for the ”graphics” board?

 

[Schroeder]

I have a VT55 that I need to spend some time on. Do you have the schematic for the ”graphics” board?

No, I don't ...

 

[leegleason]

I hope you're not disappointed with its capabilities. It can draw what DEC callls "waveform graphics". Basically, for each X position it can draw two pixels above it, along with some added capabilty to "fill" beneath a wave, draw axes and add text. Basically intended to allow you to draw graphs, using the absolute minimum amount of memory.

 

[Schroeder]

Not going to be disappointed, never ever. This is a Product build a long time ago and I have to judge it that way. For me this VT is more valueable than any Apple I. It paid a part of computer history, maybe not perfect but still giving some good lessons.

 

[Schroeder]

Did they put a Unibus video card into the Terminal. It looks ... interesting.

 

[MattisLind]

Most likely not unibus. Just hex size,and for some reason they kept the contact fingers. The fingers aren’t even gold-plated. Maybe for testing purposes?

 

[wupf]

I also watched the VT55 eBay auction. But I didn't bid because I already have a working VT78.
The VT78 (also the VT52) has the same funny 80x24 terminal electronics with the huge circuit boards and many wire jumpers, only without the additional graphics expansion.
But with a PDP-8 (IM6100), 16K CMOS RAM and two RX01 floppy drives. The 16Kx12 RAM card on the back of the CPU board in the VT78 is designed as a 4-slot DEC board with tin-plated contacts. Probably just for the module test? I haven't checked whether the OMNIBUS is similar.
Can you take some photos of the printer unit? It is not built into my VT78.

 

[spiceminer]

Congratulations @Schroeder, very nice.
The "DECScope" graphics is interesting, in case you try this feature out please share a screenshot