Re: apples vs oranges (was Re: computer video (was Re: Free IBM AT))

[Chris M]

rather then respond item by item to that barrage of
gibberish, moron, remember what prompted your original
response - I had said it was unfortunate that Apple
didn't build the MACINTOSH with a crt controller. Then
you went on to eat up unnecessary bandwidth with a
reply that meant next to nothing. And I responded
with, well, could a MACINTOSH w/o a crt controller do
this? No one is running down the Mac or the Lisa, yes
each has it's own merits. But my premise was the
MACINTOSH couldn't accomplish anything close due to
the lack of dedicated video hardware. Go back and read
the original post big man. And in the future don't
lose it just because someone shows you up.
 
--- Ray Arachelian <[EMAIL PROTECTED]> wrote:

> Eh?  Somehow I think you're being a troll.
> 
> I'm not sure how converting a modern MPG, which was
> not available back 
> in 1982, into a bunch of 80x25 or 40x25 color
> attributes and requiring a 
> sound blaster card, which did not exist at the time
> of the introduction 
> of the PC somehow proves that one system is better
> than another.  
> Especially since it was never meant to, or actually
> used in this way.
> 
> Yes, it's very cool, but, um, so what?   Each system
> has its own 
> technical merits, and it's own market, and each had
> both their own 
> successes and failures.
> 
> What I mean by 2K or 4K of bandwidth is this.  The
> stuff you see on that 
> display is not in hires or even lowres graphics.  In
> fact, it is just 
> tweaking of the color attributes, which are, as
> expected 80x25.  
> 80*25=2000 bytes.  aka 2K.  Now that display
> actually had 4K of memory 
> in that mode.  2K was used for color information,
> broken up into 
> nibbles, that is 4 bits for the foreground color,
> and 4 bits for the 
> background color.
> 
> Even that's a rather generous assumption.  You could
> go into 40x25 mode, 
> and write only to the background color, so in that
> case you're writing 
> to 1000 bytes, of which you only use half a byte for
> the 16 color 
> background - so effectively it would by 500 bytes,
> though you really do 
> have to write to all 1000 in 40x25 or all 2000 in
> 80x25.  This is what I 
> mean about it being the size of two icons.  You're
> getting excited over 
> a movie displayed in less screen real estate than an
> icon on a modern 
> display.
> 
> So, yes, the total bandwidth to display a movie in
> this way on an IBM PC 
> is well within it's capability, and while impressive
> on the surface, 
> it's still within the limits of an 8 bit 4.77MHz
> 8088. 
> 
> Indeed, I do have to wonder what decade we're
> comparing here.  MPG video 
> did not exist in 1982, and yes, when I say
> 720x364x2, I am talking about 
> the Lisa and not the Mac.  Incase you've not
> noticed, this forum is 
> called "Lisa List."  Not "The Original Mac 128
> List."  That 720x364x2 
> took up 32K of RAM vs at most 2K on the PC.  Big
> difference in bandwidth 
> there.   It's certainly not possible to capture that
> video on a PC of 
> that era and pre-process it into the format needed
> to display it back.   
> So to play back a movie on a Lisa, you'd need to
> push 32KBytes 30 times 
> a second.  To play back this demo, you need to push
> 2Kbytes 30 times a 
> second - a lot easier to do.
> 
> While I could get either an IBM PC 5150 with a CGA
> card, and color 
> monitor, or a Mac 128 for the $2.5K you mention,
> these are two different 
> products, in two different markets that have very
> little to do with each 
> other, other than both being personal computers from
> the 1980's.  The PC 
> was what, 1982, the Mac was 1984.   The Lisa, which
> is what this forum's 
> topic is about, is far closer to a mini-computer,
> and was actually built 
> by folks who previously worked on mini's.  I'd say
> it was a workstation, 
> though that word wasn't used at the time.
> 
> I'm sure that if you were to challenge someone from
> the demo scene, 
> you'll find they could come up with a dazzling demo
> that would run on a 
> stock Lisa 2 and be as impressive, if not more so.  
>  Ditto for the 
> original Mac 128 - oh wait, it was already done, and
> it talked too as 
> Larry Rosenstein already pointed out here: 
>

> 
> Which system is better?  Depends on what you want to
> do and for how 
> much.  Should the PC have had a display controller
> based on character 
> generation and attributes? What about the Apple II,
> the Commodores, et 
> al? Sure.  Should the Lisa and the Mac?  Hell no -
> it was designed on 
> purpose to always use bit mapped graphics in order
> to produce paper 
> documents.  Different markets, different price
> points, different 
> technologies, different reasons for their own
> designs.   That would be 
> comparing apples, eh, to um, oranges.
> 
> Each system has both their good and bad points, each
> has their technical 
> merits, and each has their niche.   They are all as
> wonderful as you can 
> f

Re: apples vs oranges (was Re: computer video (was Re: Free IBM AT))

[Marcin Wichary]

While I could get either an IBM PC 5150 with a CGA card, and color  
monitor, or a Mac 128 for the $2.5K you mention, these are two  
different products, in two different markets that have very little  
to do with each other, other than both being personal computers  
from the 1980's.  The PC was what, 1982, the Mac was 1984.   The  
Lisa, which is what this forum's topic is about, is far closer to a  
mini-computer, and was actually built by folks who previously  
worked on mini's.  I'd say it was a workstation, though that word  
wasn't used at the time.


That's generally true. From an article published in 1983:
"Stopping far short of any consensus is the feeling that home  
computers cost less than $500 and have less than 48K of memory.  
Personal computers cost less than $2,000 and have 48K or 64K  
standard. Desktop computers go for 64K to 256K and cost $2,000 to  
$4,000. Nobody knows what a work station is because we aren’t there yet.


These definitions, albeit probably all wet, certainly clear the air.  
Vic-20 and Atari 400 are home computers. Apple II and Atari 800 are  
personal computers. IBM pc and Apple III are desktop computers. Does  
this mean Lisa’s a work station?"


(from http://www.guidebookgallery.org/articles/lisasdebut)

--
Marcin Wichary
User interface designer, Google

Aresluna >> www.aresluna.org
10 years of Being Boring >> www.10yearsofbeingboring.com




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Re: apples vs oranges (was Re: computer video (was Re: Free IBM AT))

[Ray Arachelian]

Eh?  Somehow I think you're being a troll.

I'm not sure how converting a modern MPG, which was not available back 
in 1982, into a bunch of 80x25 or 40x25 color attributes and requiring a 
sound blaster card, which did not exist at the time of the introduction 
of the PC somehow proves that one system is better than another.  
Especially since it was never meant to, or actually used in this way.


Yes, it's very cool, but, um, so what?   Each system has its own 
technical merits, and it's own market, and each had both their own 
successes and failures.


What I mean by 2K or 4K of bandwidth is this.  The stuff you see on that 
display is not in hires or even lowres graphics.  In fact, it is just 
tweaking of the color attributes, which are, as expected 80x25.  
80*25=2000 bytes.  aka 2K.  Now that display actually had 4K of memory 
in that mode.  2K was used for color information, broken up into 
nibbles, that is 4 bits for the foreground color, and 4 bits for the 
background color.


Even that's a rather generous assumption.  You could go into 40x25 mode, 
and write only to the background color, so in that case you're writing 
to 1000 bytes, of which you only use half a byte for the 16 color 
background - so effectively it would by 500 bytes, though you really do 
have to write to all 1000 in 40x25 or all 2000 in 80x25.  This is what I 
mean about it being the size of two icons.  You're getting excited over 
a movie displayed in less screen real estate than an icon on a modern 
display.


So, yes, the total bandwidth to display a movie in this way on an IBM PC 
is well within it's capability, and while impressive on the surface, 
it's still within the limits of an 8 bit 4.77MHz 8088. 

Indeed, I do have to wonder what decade we're comparing here.  MPG video 
did not exist in 1982, and yes, when I say 720x364x2, I am talking about 
the Lisa and not the Mac.  Incase you've not noticed, this forum is 
called "Lisa List."  Not "The Original Mac 128 List."  That 720x364x2 
took up 32K of RAM vs at most 2K on the PC.  Big difference in bandwidth 
there.   It's certainly not possible to capture that video on a PC of 
that era and pre-process it into the format needed to display it back.   
So to play back a movie on a Lisa, you'd need to push 32KBytes 30 times 
a second.  To play back this demo, you need to push 2Kbytes 30 times a 
second - a lot easier to do.


While I could get either an IBM PC 5150 with a CGA card, and color 
monitor, or a Mac 128 for the $2.5K you mention, these are two different 
products, in two different markets that have very little to do with each 
other, other than both being personal computers from the 1980's.  The PC 
was what, 1982, the Mac was 1984.   The Lisa, which is what this forum's 
topic is about, is far closer to a mini-computer, and was actually built 
by folks who previously worked on mini's.  I'd say it was a workstation, 
though that word wasn't used at the time.


I'm sure that if you were to challenge someone from the demo scene, 
you'll find they could come up with a dazzling demo that would run on a 
stock Lisa 2 and be as impressive, if not more so.Ditto for the 
original Mac 128 - oh wait, it was already done, and it talked too as 
Larry Rosenstein already pointed out here: 



Which system is better?  Depends on what you want to do and for how 
much.  Should the PC have had a display controller based on character 
generation and attributes? What about the Apple II, the Commodores, et 
al? Sure.  Should the Lisa and the Mac?  Hell no - it was designed on 
purpose to always use bit mapped graphics in order to produce paper 
documents.  Different markets, different price points, different 
technologies, different reasons for their own designs.   That would be 
comparing apples, eh, to um, oranges.


Each system has both their good and bad points, each has their technical 
merits, and each has their niche.   They are all as wonderful as you can 
find reasons to use them.  An icon sized movie does not make one overall 
system better or worse, nor does it say that all systems should use 
character generator based controllers.


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Re: computer video (was Re: Free IBM AT)

[Chris M]

> Of course not, neither Mac, nor Lisa could display
> 80x25x16 or 40x25x16 
> color text mode

 Maybe that's the whole point, hmmm? The PCs have
dedicated crt controllers...the Mac didn't. These were
highly programmable, had diverse textual and graphical
modes.

>which the video makes it hard to
> distinguish between.

 Absolutely. And that's the beauty of it (it wasn't
all that hard to distinguish actually. A marvel on
such early equipment though).

> It's nice that someone bothered to write the
> assembly code to do that, 
> but, meh.  Truth be told, that's either a 2K or 4K
> display.  

 It's an original IBM CGA 5153. Not sure what you mean
by 2K or 4K.

> Compare that to digital camera displays whose real 
> state is measured in megapixels, and it's not all 
> that impressive.  It's about the size of 
> two icons, if that. :-)
 
 Ummm, what decade are we talking about here? You're
comparing a 1981 display to a post 2000 digital
camera? Get real.

> Then again, neither could the IBM PC's CGA display
> do 720x384 (half of a 
> printed page) black and white that looked as good. 

 Not sure if that's a reference to the Lisa, but the
Mac did 512 x 342. The IBM MDA card displayed 720 x
348 on any compatible monochrome monitor, any color
(paper white displays weren't commonly used with IBM
stuph). And granted, no graphics until the Hercules
card came out.
 
> Most you could get 
> from a CGA card is 640x200x2.

 True, but for $2500, the price of the original 128k
Mac IIRC, you could get a PC or compatible with double
the resolution, with 8 or 16 colors.
 
> Chris M wrote:
> 
> >let's see if I'm allowed to post to Lisa list
> today. I
> >don't know about all that. Could an early Mac do
> this:
> >
> >http://www.oldskool.org/pc/8088_Corruption 
> >  
> >
> 
> 
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Re: computer video (was Re: Free IBM AT)

[Ray Arachelian]

Of course not, neither Mac, nor Lisa could display 80x25x16 or 40x25x16 
color text mode which the video makes it hard to distinguish between.  
It's nice that someone bothered to write the assembly code to do that, 
but, meh.  Truth be told, that's either a 2K or 4K display.  Compare 
that to digital camera displays whose real estate is measured in 
megapixels, and it's not all that impressive.  It's about the size of 
two icons, if that. :-)


Then again, neither could the IBM PC's CGA display do 720x384 (half of a 
printed page) black and white that looked as good.   Most you could get 
from a CGA card is 640x200x2.



Chris M wrote:


let's see if I'm allowed to post to Lisa list today. I
don't know about all that. Could an early Mac do this:

http://www.oldskool.org/pc/8088_Corruption 
 




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Re: computer video (was Re: Free IBM AT)

[Chris M]

let's see if I'm allowed to post to Lisa list today. I
don't know about all that. Could an early Mac do this:

http://www.oldskool.org/pc/8088_Corruption 

--- Ray Arachelian <[EMAIL PROTECTED]> wrote:

> Chris M wrote:
> 
> >But Apple made a mistake with
> >the Mac by not supplying a distinct video ic,
> allowing
> >the 68k to do all the work, and therefore was
> lacking
> >in speed.
> >
> 
> That's not quite true.  Both the original Mac and
> the Lisa shared memory 
> access with the video hardware.  The video hardware
> was actually much 
> simpler than what most computers used a dedicated
> display chip for.  It 
> was basically a nothing more than a shift register
> that walked memory 
> and spat out video signals. 
> 
> Half the time the CPU had access to the memory bus,
> the other half the 
> video system.
> 
> Other contemporaries of the time may have used a
> dedicated IC to do the 
> video, *BUT* in most cases, these also shared access
> to memory with the 
> CPU.  So it was no better.  Infact, they were more
> complex because they 
> were text mode (40x25 or 80x25) and needed a
> character generator ROM.  
> The video IC would read a byte from main memory,
> then turn around an 
> read the bitmaps for that character from a ROM and
> display that.
> 
> I remember there were various tricks done to get
> various styles 
> displayed too.  For the Commodore line, there were
> several bitmaps (aka 
> fonts today) that implemented primitive graphics. 
> The high bit (128) 
> was used to invert the bitmap, so the scheme to
> display the cursor was 
> to use XOR 128 on and off every second to flash the
> character.  There 
> was a patent for this simple scheme.  Other displays
> used another chunk 
> of memory that mapped along with the text to
> implement attributes such 
> as underline, flash, inverse, and another set for
> color.
> 
> Things like the VIC20 and Commodore 64 had some
> dedicated hardware to do 
> sprites and such, it's true, but for normal
> operations, it wasn't too 
> much better what the Mac/Lisa had.  There were of
> course vector systems 
> out there, but these were mostly for games and
> worked in a totally 
> different way than raster displays like om the Mac,
> Lisa, Commodore's, 
> and PC's. 
> 
> Even so, they generally had to share the memory with
> the CPU, so there 
> was a slowdown due to that.  This can be exposed on
> the Commodore 128 by 
> going into FAST mode which ran at 2Mhz instead of
> the usual 1Mhz.  The 
> 40column display would be shut off.  (The 80 column
> one which ran off a 
> chip similar to the CGA controller still worked.) 
> Even the lowly 
> TS/1000 had a fast mode that disabled the video
> because it too shared 
> it's small memory with the video system.
> 
> 
> I don't recall whether you had to do special stuff
> to access IBM PC's 
> video memory on the CGA cards, perhaps it was
> accessible in memory 
> though the video ram as it lived on the ISA card,
> but I do recall it 
> displaying snow if you directly wrote to the video
> memory and didn't use 
> the INT21 routines in the BIOS.  Lots of program
> wrote directly to the 
> screen for speed, but had to do so in the vertical
> retrace.  (The BIOS 
> routines were very slow.)
> 
> 
> The Lisa ran at 5MHz even though the 68000 was an
> 8MHz cpu due to the 
> video circuitry needing access to memory.  I'm not
> sure how they fixed 
> this for the original Mac.  Perhaps faster RAM, or
> more likely the 
> smaller screen real estate did the trick.  In some
> ways, if you look at 
> the Mac and the Lisa, the Lisa actually had
> something like 5 CPU's 
> (68000, 6504, COPS, COPS in keyboard, and an
> optional AMD/TI FPU for the 
> early I/O boards, and a Z8 in the Profile/Widget).  
>  The Mac had to 
> rely entirely on the 68000.
> 
> They could have added one more CPU just to do
> graphics, but, that would 
> have added a lot more expense and complexity. 
> Besides, in that sort of 
> system, whenever the main CPU would need to transfer
> a big chunk of data 
> to the graphics controller instead of just
> instructions that say, draw a 
> line from this point to that point in this color,
> there would be a 
> bottle neck there.
> 
> Also, back then having a dedicated video processor
> didn't mean you could 
> do graphics primitives with it.  i.e. the chips did
> not have the silicon 
> to draw lines, boxes, in "hires" bit mapped display
> modes.  Rather the 
> CPU had to do that work and there were various
> algorithms for it.  
> QuickDraw just happened to be a better
> implementation that all of those. :-)
> 
> I'm not sure many computers had video chips that
> could offload graphics 
> work from the main CPU at that stage (i.e. hardware
> accelerated 
> graphics), except maybe perhaps for the Amiga, but
> that came later on.  
> Most were just good old fashioned frame buffers in
> bit mapped mode, and 
> character generator based displays.
> 
> -- 
> LisaList is sponsored by 

computer video (was Re: Free IBM AT)

[Ray Arachelian]

Chris M wrote:


But Apple made a mistake with
the Mac by not supplying a distinct video ic, allowing
the 68k to do all the work, and therefore was lacking
in speed.



That's not quite true.  Both the original Mac and the Lisa shared memory 
access with the video hardware.  The video hardware was actually much 
simpler than what most computers used a dedicated display chip for.  It 
was basically a nothing more than a shift register that walked memory 
and spat out video signals. 

Half the time the CPU had access to the memory bus, the other half the 
video system.


Other contemporaries of the time may have used a dedicated IC to do the 
video, *BUT* in most cases, these also shared access to memory with the 
CPU.  So it was no better.  Infact, they were more complex because they 
were text mode (40x25 or 80x25) and needed a character generator ROM.  
The video IC would read a byte from main memory, then turn around an 
read the bitmaps for that character from a ROM and display that.


I remember there were various tricks done to get various styles 
displayed too.  For the Commodore line, there were several bitmaps (aka 
fonts today) that implemented primitive graphics.  The high bit (128) 
was used to invert the bitmap, so the scheme to display the cursor was 
to use XOR 128 on and off every second to flash the character.  There 
was a patent for this simple scheme.  Other displays used another chunk 
of memory that mapped along with the text to implement attributes such 
as underline, flash, inverse, and another set for color.


Things like the VIC20 and Commodore 64 had some dedicated hardware to do 
sprites and such, it's true, but for normal operations, it wasn't too 
much better what the Mac/Lisa had.  There were of course vector systems 
out there, but these were mostly for games and worked in a totally 
different way than raster displays like om the Mac, Lisa, Commodore's, 
and PC's. 

Even so, they generally had to share the memory with the CPU, so there 
was a slowdown due to that.  This can be exposed on the Commodore 128 by 
going into FAST mode which ran at 2Mhz instead of the usual 1Mhz.  The 
40column display would be shut off.  (The 80 column one which ran off a 
chip similar to the CGA controller still worked.)  Even the lowly 
TS/1000 had a fast mode that disabled the video because it too shared 
it's small memory with the video system.



I don't recall whether you had to do special stuff to access IBM PC's 
video memory on the CGA cards, perhaps it was accessible in memory 
though the video ram as it lived on the ISA card, but I do recall it 
displaying snow if you directly wrote to the video memory and didn't use 
the INT21 routines in the BIOS.  Lots of program wrote directly to the 
screen for speed, but had to do so in the vertical retrace.  (The BIOS 
routines were very slow.)



The Lisa ran at 5MHz even though the 68000 was an 8MHz cpu due to the 
video circuitry needing access to memory.  I'm not sure how they fixed 
this for the original Mac.  Perhaps faster RAM, or more likely the 
smaller screen real estate did the trick.  In some ways, if you look at 
the Mac and the Lisa, the Lisa actually had something like 5 CPU's 
(68000, 6504, COPS, COPS in keyboard, and an optional AMD/TI FPU for the 
early I/O boards, and a Z8 in the Profile/Widget).The Mac had to 
rely entirely on the 68000.


They could have added one more CPU just to do graphics, but, that would 
have added a lot more expense and complexity.  Besides, in that sort of 
system, whenever the main CPU would need to transfer a big chunk of data 
to the graphics controller instead of just instructions that say, draw a 
line from this point to that point in this color, there would be a 
bottle neck there.


Also, back then having a dedicated video processor didn't mean you could 
do graphics primitives with it.  i.e. the chips did not have the silicon 
to draw lines, boxes, in "hires" bit mapped display modes.  Rather the 
CPU had to do that work and there were various algorithms for it.  
QuickDraw just happened to be a better implementation that all of those. :-)


I'm not sure many computers had video chips that could offload graphics 
work from the main CPU at that stage (i.e. hardware accelerated 
graphics), except maybe perhaps for the Amiga, but that came later on.  
Most were just good old fashioned frame buffers in bit mapped mode, and 
character generator based displays.


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