Space Travel (was Re: Data General Nova Star Trek)

Charles Anthony at
Fri Apr 8 07:33:43 CDT 2016

On Thu, Apr 7, 2016 at 9:35 PM, Pontus Pihlgren <pontus at> wrote:

> On Thu, Apr 07, 2016 at 04:08:42PM -0700, Charles Anthony wrote:
> >
> > I have some code that does an X-11 emulation of the Atari Tempest vector
> > graphics display; I'm thinking of wedging it into the simh PDP8 code to
> > emulate the 338 and PDP-1 displays.
> >
> That woyld be fun :) I could perhaps be used for future PDP-12
> and LINC emulators as well.
> I have read just a little about the 338. I believe it is more or
> less a dedicated PDP-8. Can you say how it compares with other
> vector displas, such as VC8E?

That is my understanding as well.

I haven't actually ever seen any of these beasts; I'm just doing on
documentation that I can find, so I am very likely wrong on some points.

There is a 338 programming manual at
a the display list opcodes.

The VC8E programming is discussed at

The VC8E has about 8 IO commands, and uses 12 bit coordinates.The commands
boil down to set X, set Y and set intensity to 0 or 1.

The 338 uses 13bit coordinates; the display has 10 bit resolution. The 338
has scaling, 8 intensity levels, delta move, character ROM, and a 36 page
programming manual.

There is a description of the VR14/VC8E at; it describes the VC8e as 50K dots
per second ont the VR14 monitor, and the 338 as 300K DPS, and mentions that
the 338 had a character ROM. built his own VC8/I for his PDP-8
and runs the PDP-8 version of space war on it. He lists the IOT
instructions for the VC8/I; they are similar to the 338.

-- Charles

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