Motorola 6845 and bitwise graphicsIBM 5153 monitor vertical resolutionHow do CGA emulators for Hercules graphics work?
Which CentOS 7 package provides the "boot" manpage?
Does cover affect melee attacks?
What is the gold linker?
What fantasy book has twins (except one's blue) and a cloaked ice bear on the cover?
Company indirectly discriminating against introverts, specifically INTJ
How does Sitecore know an event in the event queue table has been processed?
How many wires can safely be secured in a Marrette 33 wire nut?
How are Aircraft Noses Designed?
Does Darwin owe a debt to Hegel?
Does my protagonist need to be the most important character?
How to deal with people whose priority is to not get blamed?
How to find Enhantments or Artifacts that have multiple effects?
Can you use a virtual credit card to withdraw money from an ATM in the UK?
First author doesn't want a co-author to read the whole paper
RGB palette to predetermined CMYK palette in InDesign and/or Illustrator
Drawing a sequence of circles
What would be the effect of a giant magical fireball burning in the ocean?
Do more Americans want the Bidens investigated than Trump impeached?
Why is Mars cold?
Is the tap water in France safe to drink?
Why is technology bad for children?
Did I Traumatize My Puppy?
How can you tell apart the pronounciation at the end between the "meine" and "meiner" in the daily spoken situation?
Does obfuscation give any measurable security benefit?
Motorola 6845 and bitwise graphics
IBM 5153 monitor vertical resolutionHow do CGA emulators for Hercules graphics work?
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty
margin-bottom:0;
I'm curious about how graphics were drawn on systems using the Motorola 6845. I understand this was used in the CGA? If so, did the 6845 really work bitwise, was the bitwise graphics entirely separate, or did they use changing character sets on the fly to represent different patterns?
cga
asked May 13 at 12:11
Maury MarkowitzMaury Markowitz
4,4979 silver badges36 bronze badges
add a comment
|
I'm curious about how graphics were drawn on systems using the Motorola 6845. I understand this was used in the CGA? If so, did the 6845 really work bitwise, was the bitwise graphics entirely separate, or did they use changing character sets on the fly to represent different patterns?
cga
asked May 13 at 12:11
Maury MarkowitzMaury Markowitz
4,4979 silver badges36 bronze badges
add a comment
|
I'm curious about how graphics were drawn on systems using the Motorola 6845. I understand this was used in the CGA? If so, did the 6845 really work bitwise, was the bitwise graphics entirely separate, or did they use changing character sets on the fly to represent different patterns?
cga
asked May 13 at 12:11
Maury MarkowitzMaury Markowitz
4,4979 silver badges36 bronze badges
I'm curious about how graphics were drawn on systems using the Motorola 6845. I understand this was used in the CGA? If so, did the 6845 really work bitwise, was the bitwise graphics entirely separate, or did they use changing character sets on the fly to represent different patterns?
cga
cga
asked May 13 at 12:11
Maury MarkowitzMaury Markowitz
4,4979 silver badges36 bronze badges
asked May 13 at 12:11
Maury MarkowitzMaury Markowitz
4,4979 silver badges36 bronze badges
asked May 13 at 12:11
Maury MarkowitzMaury Markowitz
4,4979 silver badges36 bronze badges
asked May 13 at 12:11
Maury MarkowitzMaury Markowitz
4,4979 silver badges36 bronze badges
asked May 13 at 12:11
Maury MarkowitzMaury Markowitz
4,4979 silver badges36 bronze badges
4,4979 silver badges36 bronze badges
add a comment
|
add a comment
|
2 Answers
2
active
oldest
votes
Basically the 6845 was a bunch of counter registers, which you could program by defining end values (and sometimes start values), and use to generate RAM addresses and CRT sync signals. There was also a separate row address, so the original intention clearly was for character based displays: With a bit of additional components, you'd read some RAM content describing a character into a latch, and then you'd use this to index a ROM describing the pixel pattern for that character. Which you'd load into a shift register and shift out to the video DAC.
But of course then people also thought of ways to use this to display bit graphics. E.g. with a "character height" of 1, and no ROM access, and piping to RAM contents directly out of the shift registers. Or other variants for color.
And you could have configuration bits that control which variant of external components to use (with ROM lookup, without ROM lookup, with color table lookup).
And so, and so on. Bit the differences was all in the additional components, so "the 6845 worked bitwise" etc. doesn't really make sense.
The chip was quite successful, and used in many different ways, and the registers used ended up in the CGA, EGA, VGA etc. cards (with various extensions), and today's graphics card still have a legacy mode with this register layout. But the 6845 by itself still only is a bunch of counters.
In the 6845 data sheet, there's an example for additional components to create a character-based display, and you can read up on the details of operation.
answered May 13 at 13:41
dirktdirkt
10.7k1 gold badge27 silver badges52 bronze badges
Most excellent. So was memory bandwidth a problem if you did things bitwise? Or did it include some sort of "stuffing" system?
– Maury Markowitz
May 13 at 13:54
2
The "stuffing" system was the shift register I mentioned - RAM wasn't fast enough at that time to read memory every pixel (say, for 80x25 characters with 8x9 pixels per character), so e.g. you'd read 8 pixels at once, and then shift them out. Same for bit graphics.
– dirkt
May 13 at 13:57
The 6845 was limited to 127 rows per screen, so a character height of 1 wouldn't work. Instead, 6845-based bitmap displays would use the 6845's row output to select among several partial bitmaps of 127 or fewer lines each, which would then be displayed interleaved.
– supercat
May 13 at 21:20
On some machines that use the 6845 - certainly the Amstrad CPC and the Acorn BBC Micro - it's possible to get past the 127 line limit by changing register values mid-frame. I'm not sure how feasible that would be on a PC with a CGA card though.
– Matthew Barber
May 14 at 6:36
@supercat: I vaguely remember that some bitmap graphic modes worked by setting character height to 1; not sure about the context (it may have been a modified 6845 design that has become part of an integrated graphics card, with the total line counter width increased). Anyhow, the alternative is to set it to a power of two, and use the row address pins to address the RAM.
– dirkt
May 14 at 6:40
|
show 2 more comments
CGA and Hercules Graphics use the 6845. In graphics mode, each pixel is controlled individually, with no involvement from the character generator.
Graphics mode is controlled by bit 1 of the 03D8h control register; when it’s set, the framebuffer is treated as containing bitmap information, and when it’s cleared, the framebuffer is processed by the character generator. The bitmap layout in CGA isn’t linear; even rows come first, followed by odd rows (offset by 8 KiB). Pixels are packed, four pixels per byte in low resolution, eight pixels per byte in high resolution. Hercules has a similar interleaved layout, with four banks instead of two.
This page has lots of details on CGA.
answered May 13 at 13:40
Stephen KittStephen Kitt
50.9k9 gold badges208 silver badges213 bronze badges
add a comment
|
Your Answer
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "648"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/4.0/"u003ecc by-sa 4.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fretrocomputing.stackexchange.com%2fquestions%2f10996%2fmotorola-6845-and-bitwise-graphics%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Basically the 6845 was a bunch of counter registers, which you could program by defining end values (and sometimes start values), and use to generate RAM addresses and CRT sync signals. There was also a separate row address, so the original intention clearly was for character based displays: With a bit of additional components, you'd read some RAM content describing a character into a latch, and then you'd use this to index a ROM describing the pixel pattern for that character. Which you'd load into a shift register and shift out to the video DAC.
But of course then people also thought of ways to use this to display bit graphics. E.g. with a "character height" of 1, and no ROM access, and piping to RAM contents directly out of the shift registers. Or other variants for color.
And you could have configuration bits that control which variant of external components to use (with ROM lookup, without ROM lookup, with color table lookup).
And so, and so on. Bit the differences was all in the additional components, so "the 6845 worked bitwise" etc. doesn't really make sense.
The chip was quite successful, and used in many different ways, and the registers used ended up in the CGA, EGA, VGA etc. cards (with various extensions), and today's graphics card still have a legacy mode with this register layout. But the 6845 by itself still only is a bunch of counters.
In the 6845 data sheet, there's an example for additional components to create a character-based display, and you can read up on the details of operation.
answered May 13 at 13:41
dirktdirkt
10.7k1 gold badge27 silver badges52 bronze badges
Most excellent. So was memory bandwidth a problem if you did things bitwise? Or did it include some sort of "stuffing" system?
– Maury Markowitz
May 13 at 13:54
2
The "stuffing" system was the shift register I mentioned - RAM wasn't fast enough at that time to read memory every pixel (say, for 80x25 characters with 8x9 pixels per character), so e.g. you'd read 8 pixels at once, and then shift them out. Same for bit graphics.
– dirkt
May 13 at 13:57
The 6845 was limited to 127 rows per screen, so a character height of 1 wouldn't work. Instead, 6845-based bitmap displays would use the 6845's row output to select among several partial bitmaps of 127 or fewer lines each, which would then be displayed interleaved.
– supercat
May 13 at 21:20
On some machines that use the 6845 - certainly the Amstrad CPC and the Acorn BBC Micro - it's possible to get past the 127 line limit by changing register values mid-frame. I'm not sure how feasible that would be on a PC with a CGA card though.
– Matthew Barber
May 14 at 6:36
@supercat: I vaguely remember that some bitmap graphic modes worked by setting character height to 1; not sure about the context (it may have been a modified 6845 design that has become part of an integrated graphics card, with the total line counter width increased). Anyhow, the alternative is to set it to a power of two, and use the row address pins to address the RAM.
– dirkt
May 14 at 6:40
|
show 2 more comments
Basically the 6845 was a bunch of counter registers, which you could program by defining end values (and sometimes start values), and use to generate RAM addresses and CRT sync signals. There was also a separate row address, so the original intention clearly was for character based displays: With a bit of additional components, you'd read some RAM content describing a character into a latch, and then you'd use this to index a ROM describing the pixel pattern for that character. Which you'd load into a shift register and shift out to the video DAC.
But of course then people also thought of ways to use this to display bit graphics. E.g. with a "character height" of 1, and no ROM access, and piping to RAM contents directly out of the shift registers. Or other variants for color.
And you could have configuration bits that control which variant of external components to use (with ROM lookup, without ROM lookup, with color table lookup).
And so, and so on. Bit the differences was all in the additional components, so "the 6845 worked bitwise" etc. doesn't really make sense.
The chip was quite successful, and used in many different ways, and the registers used ended up in the CGA, EGA, VGA etc. cards (with various extensions), and today's graphics card still have a legacy mode with this register layout. But the 6845 by itself still only is a bunch of counters.
In the 6845 data sheet, there's an example for additional components to create a character-based display, and you can read up on the details of operation.
answered May 13 at 13:41
dirktdirkt
10.7k1 gold badge27 silver badges52 bronze badges
Most excellent. So was memory bandwidth a problem if you did things bitwise? Or did it include some sort of "stuffing" system?
– Maury Markowitz
May 13 at 13:54
2
The "stuffing" system was the shift register I mentioned - RAM wasn't fast enough at that time to read memory every pixel (say, for 80x25 characters with 8x9 pixels per character), so e.g. you'd read 8 pixels at once, and then shift them out. Same for bit graphics.
– dirkt
May 13 at 13:57
The 6845 was limited to 127 rows per screen, so a character height of 1 wouldn't work. Instead, 6845-based bitmap displays would use the 6845's row output to select among several partial bitmaps of 127 or fewer lines each, which would then be displayed interleaved.
– supercat
May 13 at 21:20
On some machines that use the 6845 - certainly the Amstrad CPC and the Acorn BBC Micro - it's possible to get past the 127 line limit by changing register values mid-frame. I'm not sure how feasible that would be on a PC with a CGA card though.
– Matthew Barber
May 14 at 6:36
@supercat: I vaguely remember that some bitmap graphic modes worked by setting character height to 1; not sure about the context (it may have been a modified 6845 design that has become part of an integrated graphics card, with the total line counter width increased). Anyhow, the alternative is to set it to a power of two, and use the row address pins to address the RAM.
– dirkt
May 14 at 6:40
|
show 2 more comments
Basically the 6845 was a bunch of counter registers, which you could program by defining end values (and sometimes start values), and use to generate RAM addresses and CRT sync signals. There was also a separate row address, so the original intention clearly was for character based displays: With a bit of additional components, you'd read some RAM content describing a character into a latch, and then you'd use this to index a ROM describing the pixel pattern for that character. Which you'd load into a shift register and shift out to the video DAC.
But of course then people also thought of ways to use this to display bit graphics. E.g. with a "character height" of 1, and no ROM access, and piping to RAM contents directly out of the shift registers. Or other variants for color.
And you could have configuration bits that control which variant of external components to use (with ROM lookup, without ROM lookup, with color table lookup).
And so, and so on. Bit the differences was all in the additional components, so "the 6845 worked bitwise" etc. doesn't really make sense.
The chip was quite successful, and used in many different ways, and the registers used ended up in the CGA, EGA, VGA etc. cards (with various extensions), and today's graphics card still have a legacy mode with this register layout. But the 6845 by itself still only is a bunch of counters.
In the 6845 data sheet, there's an example for additional components to create a character-based display, and you can read up on the details of operation.
answered May 13 at 13:41
dirktdirkt
10.7k1 gold badge27 silver badges52 bronze badges
Basically the 6845 was a bunch of counter registers, which you could program by defining end values (and sometimes start values), and use to generate RAM addresses and CRT sync signals. There was also a separate row address, so the original intention clearly was for character based displays: With a bit of additional components, you'd read some RAM content describing a character into a latch, and then you'd use this to index a ROM describing the pixel pattern for that character. Which you'd load into a shift register and shift out to the video DAC.
But of course then people also thought of ways to use this to display bit graphics. E.g. with a "character height" of 1, and no ROM access, and piping to RAM contents directly out of the shift registers. Or other variants for color.
And you could have configuration bits that control which variant of external components to use (with ROM lookup, without ROM lookup, with color table lookup).
And so, and so on. Bit the differences was all in the additional components, so "the 6845 worked bitwise" etc. doesn't really make sense.
The chip was quite successful, and used in many different ways, and the registers used ended up in the CGA, EGA, VGA etc. cards (with various extensions), and today's graphics card still have a legacy mode with this register layout. But the 6845 by itself still only is a bunch of counters.
In the 6845 data sheet, there's an example for additional components to create a character-based display, and you can read up on the details of operation.
answered May 13 at 13:41
dirktdirkt
10.7k1 gold badge27 silver badges52 bronze badges
edited May 13 at 14:00
answered May 13 at 13:41
dirktdirkt
10.7k1 gold badge27 silver badges52 bronze badges
answered May 13 at 13:41
dirktdirkt
10.7k1 gold badge27 silver badges52 bronze badges
answered May 13 at 13:41
dirktdirkt
10.7k1 gold badge27 silver badges52 bronze badges
10.7k1 gold badge27 silver badges52 bronze badges
Most excellent. So was memory bandwidth a problem if you did things bitwise? Or did it include some sort of "stuffing" system?
– Maury Markowitz
May 13 at 13:54
2
The "stuffing" system was the shift register I mentioned - RAM wasn't fast enough at that time to read memory every pixel (say, for 80x25 characters with 8x9 pixels per character), so e.g. you'd read 8 pixels at once, and then shift them out. Same for bit graphics.
– dirkt
May 13 at 13:57
The 6845 was limited to 127 rows per screen, so a character height of 1 wouldn't work. Instead, 6845-based bitmap displays would use the 6845's row output to select among several partial bitmaps of 127 or fewer lines each, which would then be displayed interleaved.
– supercat
May 13 at 21:20
On some machines that use the 6845 - certainly the Amstrad CPC and the Acorn BBC Micro - it's possible to get past the 127 line limit by changing register values mid-frame. I'm not sure how feasible that would be on a PC with a CGA card though.
– Matthew Barber
May 14 at 6:36
@supercat: I vaguely remember that some bitmap graphic modes worked by setting character height to 1; not sure about the context (it may have been a modified 6845 design that has become part of an integrated graphics card, with the total line counter width increased). Anyhow, the alternative is to set it to a power of two, and use the row address pins to address the RAM.
– dirkt
May 14 at 6:40
|
show 2 more comments
Most excellent. So was memory bandwidth a problem if you did things bitwise? Or did it include some sort of "stuffing" system?
– Maury Markowitz
May 13 at 13:54
2
The "stuffing" system was the shift register I mentioned - RAM wasn't fast enough at that time to read memory every pixel (say, for 80x25 characters with 8x9 pixels per character), so e.g. you'd read 8 pixels at once, and then shift them out. Same for bit graphics.
– dirkt
May 13 at 13:57
The 6845 was limited to 127 rows per screen, so a character height of 1 wouldn't work. Instead, 6845-based bitmap displays would use the 6845's row output to select among several partial bitmaps of 127 or fewer lines each, which would then be displayed interleaved.
– supercat
May 13 at 21:20
On some machines that use the 6845 - certainly the Amstrad CPC and the Acorn BBC Micro - it's possible to get past the 127 line limit by changing register values mid-frame. I'm not sure how feasible that would be on a PC with a CGA card though.
– Matthew Barber
May 14 at 6:36
@supercat: I vaguely remember that some bitmap graphic modes worked by setting character height to 1; not sure about the context (it may have been a modified 6845 design that has become part of an integrated graphics card, with the total line counter width increased). Anyhow, the alternative is to set it to a power of two, and use the row address pins to address the RAM.
– dirkt
May 14 at 6:40
Most excellent. So was memory bandwidth a problem if you did things bitwise? Or did it include some sort of "stuffing" system?
– Maury Markowitz
May 13 at 13:54
Most excellent. So was memory bandwidth a problem if you did things bitwise? Or did it include some sort of "stuffing" system?
– Maury Markowitz
May 13 at 13:54
2
2
The "stuffing" system was the shift register I mentioned - RAM wasn't fast enough at that time to read memory every pixel (say, for 80x25 characters with 8x9 pixels per character), so e.g. you'd read 8 pixels at once, and then shift them out. Same for bit graphics.
– dirkt
May 13 at 13:57
The "stuffing" system was the shift register I mentioned - RAM wasn't fast enough at that time to read memory every pixel (say, for 80x25 characters with 8x9 pixels per character), so e.g. you'd read 8 pixels at once, and then shift them out. Same for bit graphics.
– dirkt
May 13 at 13:57
The 6845 was limited to 127 rows per screen, so a character height of 1 wouldn't work. Instead, 6845-based bitmap displays would use the 6845's row output to select among several partial bitmaps of 127 or fewer lines each, which would then be displayed interleaved.
– supercat
May 13 at 21:20
The 6845 was limited to 127 rows per screen, so a character height of 1 wouldn't work. Instead, 6845-based bitmap displays would use the 6845's row output to select among several partial bitmaps of 127 or fewer lines each, which would then be displayed interleaved.
– supercat
May 13 at 21:20
On some machines that use the 6845 - certainly the Amstrad CPC and the Acorn BBC Micro - it's possible to get past the 127 line limit by changing register values mid-frame. I'm not sure how feasible that would be on a PC with a CGA card though.
– Matthew Barber
May 14 at 6:36
On some machines that use the 6845 - certainly the Amstrad CPC and the Acorn BBC Micro - it's possible to get past the 127 line limit by changing register values mid-frame. I'm not sure how feasible that would be on a PC with a CGA card though.
– Matthew Barber
May 14 at 6:36
@supercat: I vaguely remember that some bitmap graphic modes worked by setting character height to 1; not sure about the context (it may have been a modified 6845 design that has become part of an integrated graphics card, with the total line counter width increased). Anyhow, the alternative is to set it to a power of two, and use the row address pins to address the RAM.
– dirkt
May 14 at 6:40
@supercat: I vaguely remember that some bitmap graphic modes worked by setting character height to 1; not sure about the context (it may have been a modified 6845 design that has become part of an integrated graphics card, with the total line counter width increased). Anyhow, the alternative is to set it to a power of two, and use the row address pins to address the RAM.
– dirkt
May 14 at 6:40
|
show 2 more comments
CGA and Hercules Graphics use the 6845. In graphics mode, each pixel is controlled individually, with no involvement from the character generator.
Graphics mode is controlled by bit 1 of the 03D8h control register; when it’s set, the framebuffer is treated as containing bitmap information, and when it’s cleared, the framebuffer is processed by the character generator. The bitmap layout in CGA isn’t linear; even rows come first, followed by odd rows (offset by 8 KiB). Pixels are packed, four pixels per byte in low resolution, eight pixels per byte in high resolution. Hercules has a similar interleaved layout, with four banks instead of two.
This page has lots of details on CGA.
answered May 13 at 13:40
Stephen KittStephen Kitt
50.9k9 gold badges208 silver badges213 bronze badges
add a comment
|
CGA and Hercules Graphics use the 6845. In graphics mode, each pixel is controlled individually, with no involvement from the character generator.
Graphics mode is controlled by bit 1 of the 03D8h control register; when it’s set, the framebuffer is treated as containing bitmap information, and when it’s cleared, the framebuffer is processed by the character generator. The bitmap layout in CGA isn’t linear; even rows come first, followed by odd rows (offset by 8 KiB). Pixels are packed, four pixels per byte in low resolution, eight pixels per byte in high resolution. Hercules has a similar interleaved layout, with four banks instead of two.
This page has lots of details on CGA.
answered May 13 at 13:40
Stephen KittStephen Kitt
50.9k9 gold badges208 silver badges213 bronze badges
add a comment
|
CGA and Hercules Graphics use the 6845. In graphics mode, each pixel is controlled individually, with no involvement from the character generator.
Graphics mode is controlled by bit 1 of the 03D8h control register; when it’s set, the framebuffer is treated as containing bitmap information, and when it’s cleared, the framebuffer is processed by the character generator. The bitmap layout in CGA isn’t linear; even rows come first, followed by odd rows (offset by 8 KiB). Pixels are packed, four pixels per byte in low resolution, eight pixels per byte in high resolution. Hercules has a similar interleaved layout, with four banks instead of two.
This page has lots of details on CGA.
answered May 13 at 13:40
Stephen KittStephen Kitt
50.9k9 gold badges208 silver badges213 bronze badges
CGA and Hercules Graphics use the 6845. In graphics mode, each pixel is controlled individually, with no involvement from the character generator.
Graphics mode is controlled by bit 1 of the 03D8h control register; when it’s set, the framebuffer is treated as containing bitmap information, and when it’s cleared, the framebuffer is processed by the character generator. The bitmap layout in CGA isn’t linear; even rows come first, followed by odd rows (offset by 8 KiB). Pixels are packed, four pixels per byte in low resolution, eight pixels per byte in high resolution. Hercules has a similar interleaved layout, with four banks instead of two.
This page has lots of details on CGA.
answered May 13 at 13:40
Stephen KittStephen Kitt
50.9k9 gold badges208 silver badges213 bronze badges
answered May 13 at 13:40
Stephen KittStephen Kitt
50.9k9 gold badges208 silver badges213 bronze badges
answered May 13 at 13:40
Stephen KittStephen Kitt
50.9k9 gold badges208 silver badges213 bronze badges
answered May 13 at 13:40
Stephen KittStephen Kitt
50.9k9 gold badges208 silver badges213 bronze badges
50.9k9 gold badges208 silver badges213 bronze badges
add a comment
|
add a comment
|
Thanks for contributing an answer to Retrocomputing Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fretrocomputing.stackexchange.com%2fquestions%2f10996%2fmotorola-6845-and-bitwise-graphics%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
