Post by Herb JohnsonPost by Claudio PuvianiPost by Lee HartI think you are overly pessimistic. There have been quite a few
computers with graphical user interfaces that had what would be
considered pitiful amounts of speed and memory by today's bloated
standards....the Xerox Alto...Apple Macintosh...
I don't know if you haven't worked with 68000s or if you haven't worked with
Z80s, but you clearly haven't worked with both....The two aren't
even in the same ball park. If someone had duplicated the core
functionality of the Mac GUI on a Z80, not only would it have required
hardware upgrades that would have been absurd at the time, but the
result would have been so sluggish as to make it useless. As it was,
even the 68000 could barely function comfortably with all that
overhead.
And yet it happened. The Heath H89 WAS a Z80 system with simple
graphics.
As were many others. None of them offered a GUI on the order of the Mac. Graphics
were custom-programmed for each application.
Post by Herb JohnsonCompanies DID make expensive hardware upgrades to provide bit
graphics. They WERE bought and people used them for various
purposes.
No one ever disputed that. What's in dispute is the practicality (and sanity) of
developing a Mac-scale GUI for these systems.
Post by Herb JohnsonAs for the Macintosh 128K, I don't see it as particularly sluggish.
Scroll through a spreadsheet for a while and you'll see how sluggish it can be.
Post by Herb JohnsonI should know, I sell them and their successors (512K, Plus, SE, etc)
every day.
I'm sure you do. I don't see how that makes you a better authority than people
who had used and programmed the originals when they first came out.
Post by Herb JohnsonFor the applications they run, they run as fast by HUMAN standards as
similar applications today.
I disagree. Taking the same example of scrolling through a speadsheet, it was
much less sluggish to navigate through Supercalc or Visicalc than it was to
navigate an Excel page on the early Macs. It was comfortable enough for someone
who ONLY knew the Mac, but for anyone used to earlier spreadsheets, the Mac
seemed slow. This doesn't negate the other advantages that Excel on the Mac
offered, but the topic here is about the performance of graphics, and the
performance of early Mac graphics was definitely just a hair over the threshold
of acceptability.
Post by Herb JohnsonIt's a common error these days, to use modern standards and prices and
then to look backward and say "how absurd that people payed so much
for so little, such slow machines, tsk tsk..."
Maybe, but that's completely irrelevant to this conversation since the
comparisons we're making are between early Z80-based systems and early
68000-based systems. Neither I nor anyone else ever brought up modern systems or
standards.
Post by Herb JohnsonIt's another error, but one of ignorance, to not know what was available for
those systems at that time.
If you're directing that at me, you're shooting yourself in the foot. I was
familiar with the microcomputer markets since 1976.
Post by Herb JohnsonIf you are not familiar with the history of H89 third-party products, I'm sure
Mr. Hart (who is) or others can fill you in.
I'm quite familiar with the Heath/Zenith prducts. How they're in any way relevant
to the conversation is beyond me.
Post by Herb JohnsonFor that matter there were bit-graphic products for the ADM-3
terminal, the DEC VT-100 terminal, and of course many
bit-graphic S-100 cards.
Big deal. Bitmap graphics were available for dozens of systems. Availability
isn't at issue, it's PERFORMANCE that was the problem.
Post by Herb JohnsonI'm sorry to say that people back then did not have the good sense to
wait for or use faster processors and cheaper hardware as you suggest.
I suggested no such thing. Either you're making things up to support a flimsy
argument, or you have problems reading what's actually written. What I said was
that no one was stupid enough to waste time writing a Mac-scale GUI for Z80
systems. Of course people used raw graphics for a variety of applications. For
someone who allegedly sells Macs every day, it's amazing that you can't make a
distinction between a full-fledged GUI and low-level graphics.
Post by Herb JohnsonWe were too busy getting things done.
I was part of that "we". It's precisely because we were too busy getting things
done that we weren't engaging in idiocy like trying to implement a Mac-like GUI
on inadequate hardware.
Post by Herb JohnsonPost by Claudio PuvianiThe real reason is that the people who had the skill and knowledge to
write GUIs knew enough to not waste their time writing one for a
platform that was, by then, already obsolete only to produce software
that would have been unacceptable to the end users.
I've been debating on whether this thread is just a draw for some kind
of fight or a legitimate discussion of graphics under CP/M.
This from a salesperson who's blindly spitting out accusations of ignorance to a
20-year software engineer.
Post by Herb JohnsonI find remarks like the above paragraph to be evidence for the former.
The remark that you're criticizing explains the rationale of software developers
at the time. There's nothing beligerent about it. People who program for a living
don't waste time writing software that won't sell and there's nothing wrong or
antagonistic about recognizing, in 1983, that the CP/M-80 platform was becoming
obsolete.
Post by Herb JohnsonBut the gist of the non-grumpy discussion is that any retroactive graphic
developments for CP/M are limited today, as they were then, by the lack of
resources in older systems.
That was my point. Mr. Hart argued that a 4MHz Z80 system had the same
capabilities as a 6MHz 68000 system and I refuted the claim.
Post by Herb JohnsonThat includes a lack of standards for graphics hardware
That's really not a big limitation. If the graphics software is written
correctly, the hardware differences can be encapsulated in a very small set of
functions. Most graphical programming is platform independent.
Post by Herb Johnsonand limitations in memory and speed.
There, we totally agree.
Post by Herb JohnsonI see no shame in all of that, such limits existed in the post-CP/M
computer world for some years;
Who said anything about shame? That early CP/M-80 systems were inadequate to the
development of full GUIs is a simple statement of fact, not an indictment.
Post by Herb Johnsontoday such limits only apply to extreme applications like 3D rendering and
simulation.
And maybe tomorrow's restrictions will apply to holograms and later, maybe to
something more complicated. The point is that every technology has its limits and
Z80 systems definitely had a low ceiling when it came to graphics.
Post by Herb JohnsonThe other difficulty with this thread is that no applications are
specified, so there is no performance criterion.
The application was specified from the start and in the thread's subject: a GUI.
Performance criteria are evident to anyone who's done graphics programming:
opaque and transparent blitting, line/curve plotting, fills. These are the basic
building blocks of any 2D graphical system and their performance is easily
quantifyable.
Post by Herb JohnsonSo one can always be sour grapes about the situation simply by setting
goals too high.
The goal was set too high the moment a Mac-style GUI was proposed for CP/M-80
systems. It's certainly interesting as an experiment, and I encouraged the OP to
try it, but by no means is this a practical idea.
Post by Herb JohnsonOr, one can look back and say what WAS accomplished within
the so-called limits of the times,
Except this thread isn't about what WAS accomblished but rather about what COULD
BE accomplished. There have been many threads about reminiscing. This just isn't
one of them. Feel free to start one if that's your personal preference.
Post by Herb Johnsonwhich of course were leading edge relative to times even more remote.
I prefer the latter approach, as even today there are applications which
are resourse limited and which can benefit from knowledge and
experience acquired from predecessor applications in a similarly limited
environment.
Unfortunately, the experience gained in software development for early 8-bit
systems is mostly inapplicable to today's large-scale software development. The
techniques are still in use in small-scale embedded systems, but that's an
entirely different world.
Post by Herb JohnsonIt seems to me the challenge of working in a resource-limited but
FAMILIAR and STABLE programming environment has drawn
more interest in the last few years, not less.
If you're talking about HOBBYIST programming, then I agree. Professionals -- for
better or for worse -- have a different set of challenges today.
Post by Herb JohnsonI see more "tribute" Web sites to CP/M, Atari, and other classic
computers every month, and new developments in hardware
and software.
Which is a good thing for those of us who are keeping old memories fresh.
Post by Herb JohnsonSo I find remarks about "wasting time" with such systems to be as ironic
today as they were a few decades ago when CP/M was new.
Again with the misinterpretation. Read what I actually wrote. If you're going to
make up both ends of the dialog, I don't see why you bother interacting with
others. The "wasted time", as I explained more than once, refers to the idea that
early 1980's programmers would try duplicate the work that was done on Macs. It's
amazing to me that anyone could extrapolate that to apply to any work done on
early systems or to apply it to what hobbyists are doing today.
Claudio Puviani