Imlac assembler almost ready...

From: Ben Franchuk <bfranchuk_at_jetnet.ab.ca>
Date: Sat Sep 14 15:54:01 2002

Bob Shannon wrote:

> To suggest that nothing better was available to the engineering team at
> Imlac is laughable at best.

Ok I did not look at the schematic.


> What makes you say something like this Ben? For what the Imlac did,
> when it did it, VECTOR was
> FAR SUPERIOR to raster displays.

I agree the VECTOR display is the way to go.

> Please note, the Imlac had a 1024 by 1024 addressable display, prior to
> 1970. This greatly exceeds what
> was possible with raster graphics at the time, and the Imlac was
> designed for calligraphic applications where
> its short vectors made for a mugh higher quality display than a
> pixellated raster display of the same resolution
> would have. There is also the fact that manipulating raster display is
> far more computationally intensive than
> manipulating a vector display list. The Imlac CPU would not be well
> suited for raster graphics at all, but its more
> than sufficient for its intended use.

I was thinking with the lack of modern CRT tubes
implimenting the VECTOR display will be rather difficult.

> The problems with the Imlac are issues of engineering quality, like the
> total lack of decoupling capacitors, poor
> grounding, and poor logic design. This is also reflected in the
> manufacturing of early units in the failue to wash the
> etchant off the boards (many Imlac boards now have fuzzy green etches,
> or no remaining etches at all) and poor metal preperation prior to
> painting, and the fact that the design was very quickly repackaged as
> the PDS-1D's.
Good point.


> The CRT used in the Imlac was common enough in its day, and that same
> tube was also used in much higher quality products as well.
<snip>
> On the other hand, a Wells Gardner vector monitor is more than able to
> display the vector video from an Imlac exactly the way a real Imlac
> does. So will most small oscilloscopes, or even a modified TV monitor.
> Small vector display monitors are fairly common on eBay at very
> affordable prices. So whats the problem with a vector display?

Where? That is something I never knew.

> To be true to the original, I'm sticking with a true vector display.
> After all, I'm quite addicted to vector (and point plot) displays, and
> this was my main attraction to the Imlac. If this were replaced by a
> raster display, you might as well run a software emulator and not bother
> re-implementing the Imlac in hardware at all.
>
> The vector display of the Imlac is a thing of beauty and is a huge part
> of what makes an Imlac so unique. To call this "...the real problem..."
> is heracy!
>
I am saying creating a good design will be rather difficult.I would like to see
this implimented as a new design, You are right vector is the way to go.
Received on Sat Sep 14 2002 - 15:54:01 BST