
High-Res Graphics on a Text-Only TRS-80 Model 4 from 1983 - blakespot
http://www.bytecellar.com/2018/10/17/enjoying-high-res-graphics-on-a-text-only-trs-80-model-4-from-1983/
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boomlinde
A bit disappointed that this was just a matter of installing a graphics board
in a machine designed to host one when it sounds like it would be a nifty hack
from the title.

Still an interesting read to someone like me who knows very little about the
Radio Shack computers.

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torgoguys
I had a lot of fun with a TRS80 Model 4D when I was a kid. The article
actually has the "text mode graphics" resolution wrong. There were characters
divided 2x3 blocks so you could divide the 80x24 character screen into 160x72
”pixels” natively, without the extra hardware used in the article.

Since characters were simultaneously available at the full hi res of the
screen, this allowed me to make a pretty nice looking rouguelike style game.
Text heavy, but using the block pixels for walls and some limited graphics
effects.

~~~
kbutler
The Model III display was only 64 characters per line (64x16), so the 2x3
blocks gave you 128 horizontal "pixels". Model 4 could operate in either Model
III (backward compatible) or Model 4 mode.

Moving to 80x24 on PC from a Model III was _huge_.

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pohl
This post made my childhood come rushing back. I was fortunate to grow up with
a new-at-the-time Model I, which my father and I upgraded piecemeal from a
Level I Basic ROM to the Level II ROM, then adding the expansion bay, filling
it with 48K (16K at a time), then the chip that allowed displaying lowercase
letters, and eventually 4 external double-density floppy drives.

The Model 4 was the machine that I would daydream about while flipping through
Radio Shack catalogs and "80 Microcomputing" magazine. I was determined that,
when I grew up, I'd have a Model 4 with both banks of RAM (128K total) and 4
internal half-height floppy drives in the bays (I don't think that was
possible, in retrospect), and the hi-res card.

I still love the look of this machine.

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potta_coffee
This was my first computer. Dad threw it away when I was at college, I was
disappointed. Wish I still had it.

~~~
behringer
Come to Tandy Assembly next month in OH and relive your glory days.

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potta_coffee
That would be awesome! I'm way far away from OH though.

~~~
behringer
There's also CoCo Fest in Chicago, it's more color computer related but there
are model 1-4s there sometimes.

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XalvinX
In about 1980 or so i got a TI 99/4A (I was about 12) and figured out how to
do high-res graphics within the limitations of what was essentially a text-
only machine. By redefining the 8x8 character blocks you could manipulate
individual pixels. The main limitation was that when you redefined one
character, every one of that number on the screen would change, and I think
there were 256 available...still though, i managed to create programs that
could graph a line and draw circles, and something that was similar to Missile
Command. it was also interesting in that if, for example, you filled the whole
screen with a single character and then redefined it in a loop or something,
the whole screen would instantly update creating mesmerizing effects. You had
to be creative in those days.

~~~
mmjaa
My favourite 8-bit machine, the Oric-1/Atmos range of systems, had a secret
video mode embedded in its bowels that we didn't know much about until this
century. It turns out there is a way to do color rendering on the Oric that
precludes the attribute clash that inflicted so many systems of the era .. and
we didn't find out about it until one of our most elite hackers dug deep.

Since then, there's been a re-birth of new titles written for the Oric to
exploit this graphics mode .. and it has resulted in titles that, had they
occurred in the 80's, would have propelled the Oric far further into the scene
- perhaps. (Perhaps, it was already too late for the Oric by the time it
arrived...)

I find it fascinating that these machines still hold so many treasures yet to
discover. And, it sure is fun to be writing software for an 8-bit machine,
with only perhaps a few hundred users out there who would give a damn ..

~~~
andrewstuart
any references to this display mode? I can't find anything on it on the net.

~~~
mmjaa
Here's an intro to Oric display in general:

[http://www.defence-
force.org/computing/oric/coding/part_7/in...](http://www.defence-
force.org/computing/oric/coding/part_7/index.htm)

Here's more details on the attributes mode that, when properly grok'ed, gives
us color options never before seen on the Oric:

[http://thespider.oric.org/oric_hires_colour.html](http://thespider.oric.org/oric_hires_colour.html)

Twilighte (RIP) exploited this extensively for his games - check out
[http://oric.org/](http://oric.org/) for his titles (they're in the top-10) ..

See also this thread:

[http://forum.defence-
force.org/viewtopic.php?f=14&t=875](http://forum.defence-
force.org/viewtopic.php?f=14&t=875)

~~~
foobarge
Thank you - this is quite a find. I remember banging my head against the
limitations of the HIRES mode and eventually doing everything in text mode
with redefined characters - I was working on a windowing system at the time.

Best thing in for summer was two weeks with my grand father, my Atmos and my
monitor - and certainly not my mom telling me to get out in the sun (and my
grand father couldn't care less.)

~~~
mmjaa
Great to encounter another Atmos fan on HN .. have you been following the
OricExos project? Its a system consisting of 4 Oric's, tied together, sharing
duties for graphics and sound .. pretty amazing hack, if I do say so myself:

[http://forum.defence-
force.org/viewtopic.php?f=21&t=1880](http://forum.defence-
force.org/viewtopic.php?f=21&t=1880)

Check out some of the demo's at the end of the thread .. it was recently
booted up and demonstrated adding new color resolutions to the system. Truly
mind-boggling!

