6 ms·

You can’t let a broken CRT monitor stand in your way

118 points by duck 11y ago

mmastrac 11y ago
This was awesome. I feel like there's something lost when devices are locked down so tight that you can't hack on them at a low level (despite whatever risks present themselves). I remember using Norton Disk Editor in the early 90's to fix directory entries (and occasionally break them!). I learned some fantastic lessons about backups and how to recover from mistakes. This is the reason that I'm firmly stuck in the Android camp (on devices that I can root). I'm one a very, very small minority though.
- chadzawistowski 11y ago
  I echo the sentiment but think Android doesn't go far enough; especially as apps migrate to relying on the closed/proprietary Google Play Services framework rather than vanilla Android. I'm anxiously awaiting the https://neo900.org/ https://neo900.org/
  - jrcii 11y ago
    I'm a big fan of this project, too. However I'm disappointed that the final price is going to come out to about $1200 http://neo900.org/estimate http://neo900.org/estimate There seems to be a fair amount of money and attention being invested in secure messaging, Mark Cuban's Cyber Dust, Blackphone, the various things by Moxie's Open Whisper Systems, etc. However the Neo900 as far as I know is the only solution offering a sandboxed baseband which is critical.
    - dTal 11y ago
      The Pyra Console [https://pyra-handheld.com/ https://pyra-handheld.com/] has a sandboxed baseband (in that it's a seperate chip controlled by tty with no direct access to anything), and at 500 Euros to obsolete my netbook and my phone in one go, I will certainly be getting one. Pre-orders should be opening any day now.
      - gr3yh47 11y ago
        What is it going to need to make it function as a phone?
        dTal 11y ago
        Well, it runs stock Debian- so I imagine either the freesmartphone.org stack or oFono (both packaged), coupled with a relevant user interface. Really the UI is the hard bit, you can send and receive SMS just by cat-ing stuff to the tty device. Ubuntu has a lot of oFono-based UI stuff that can be stolen, though there's quite a few dependencies. Given how the Pandora community rallied around their platform, I've no doubt that we'll end up with a plug-and-play solution before long. Also it'll probably be awkward for phone calls without some sort of headset (or just putting up with speakerphone all the time), but I hardly ever make calls anyway and it'll more than make up for that by being awesome at texting.
  - rtkwe 11y ago
    > especially as apps migrate to relying on the closed/proprietary Google Play Services framework rather than vanilla Android. Blame the manufacturers, Google started moving more and more functionality into the services instead of the base OS partially because manufacturers were being so horrible about updating their phones. With functionality in the Services instead of the base OS they can update functions without manufactures deciding that it's not worth their time and holding things back.
    - chadzawistowski 11y ago
      I don't blame anyone, I just find the result undesirable.
- justinlardinois 11y ago
  > This is the reason that I'm firmly stuck in the Android camp (on devices that I can root). I'm one a very, very small minority though. How do you figure you're a minority? Android has the highest market share of any smartphone OS in most parts of the world, developed or otherwise.
  - schoen 11y ago
    Maybe it's that a minority of people currently see the user-modifiability of Android devices as an important benefit, not that a minority of smartphone users use Android.
kazinator 11y ago
> The cruel joke? In business mode, the picture was fine. The problem, whatever it was, manifested itself only in casual mode: the mode all the games used. Curious terminology. A high resolution text mode being stable, but a low-res graphics mode going haywire is almost certainly an issue with the display adapter and not the cathode ray tube.
- rzzzt 11y ago
  I'd blace my bet on the deflection circuits (horizontal output transistor). I had similar problems with a more recent CRT, where the top right corner of the image started to shake frantically after a few minutes if you switched to high resolution modes. EDIT: It seems I didn't catch any of the details right... the author's display was probably not multisync and developed problems in the low resolution mode. Oh well.
- wnoise 11y ago
  EGA was "dual-sync": in the 200 line modes, it ran at 15 kHz, whereas the 350 line modes ran at 23 kHz. While it's quite possible that the card had the problem, it's also possible that CRT was the problem. If the components drifted out of spec, it might no longer be able to correctly sync at 15 kHz, especially after warming up.
- mikejmoffitt 11y ago
  The problems being described sound like capacitors that have gone bad in the deflection circuitry. In the world of arcade machines, which run CRT monitors for hours on end every day, this failure mode is very common, and it shows as a "curl" on one or more sides of the display.
- qb45 11y ago
  I love those remote debugging sessions :) I have never seen those circuits so can't comment on what could be wrong, but if cooling the monitor helped I think it wasn't EGA's fault. Too bad the OP didn't keep this machine.
- Animats 11y ago
  The tube itself probably wasn't the problem. Trouble with the electron guns usually means a dead tube, or a dead color. Problems related to sweep are outside the tube. If he had a problem that appeared as overheating, the first thing to try is freeze spray. Find out what component is temperature sensitive. It's probably a capacitor. It's not that hard to work on a CRT unit. You have to discharge the second anode voltage after powering off. (I was once trained to repair analog radios and TVs. This is now a totally useless skill.)
apricot 11y ago
Nice article, but it could have done without the awful monikers "business mode" and "casual mode". I instinctively went for the shift keys fractions of a second after seeing that Sidekick menu.
gtrubetskoy 11y ago
Attempting to take apart a TV set back in my childhood got me a lesson in that just because it's not plugged in, doesn't mean there is no electricity in it, those capacitors pack a punch one never forgets.
- girvo 11y ago
  I made the same mistake. Once. You certainly don't make that mistake again!
thangalin 11y ago
Many moons ago, my CRT monitor's red gun went kaput. It's easy to imagine what that must have looked like. Anything red appeared as, well, black. Everything else was a shade of cyan, blue, or green. The solution? A TSR, like in the article. The TSR I wrote was simple in comparison: it constantly refreshed the palette. A palette entry with a red value greater than zero had its blue and green values increased accordingly. The red component was then zeroed out. Necessity is a powerful impetus for spurring creativity in frugal college students. This looks to be an earlier version, as it doesn't increase the blue and green values, but gives an idea of how it worked: {$M 1024,0,0 } { 1K stack, no heap } USES Crt, DOS; CONST MAX_COUNT = 384; READ_PAL = $3C7; WRIT_PAL = $3C8; RED = 1; GRN = 2; BLU = 3; VAR OldIntVec : PROCEDURE; NoRed : ARRAY[ RED..BLU, 0..255 ] OF BYTE; Count : INTEGER; Colour : BYTE; PROCEDURE ReadPalette; Begin FOR Colour := 0 TO 255 DO Begin Port[ $3C7 ] := Colour; NoRed[ RED, Colour ] := Port[ $3C9 ]; NoRed[ GRN, Colour ] := Port[ $3C9 ]; NoRed[ BLU, Colour ] := Port[ $3C9 ]; End; End; PROCEDURE ChngPalette; Begin FOR Colour := 0 TO 255 DO IF NoRed[ RED, Colour ] <> 0 THEN NoRed[ RED, Colour ] := 0; End; PROCEDURE WritePalette; Begin FOR Colour := 0 TO 255 DO Begin Port[ $3C8 ] := Colour; Port[ $3C9 ] := NoRed[ RED, Colour ]; Port[ $3C9 ] := NoRed[ GRN, Colour ]; Port[ $3C9 ] := NoRed[ BLU, Colour ]; End; End; {$F+} PROCEDURE NewTimer; INTERRUPT; Begin InLine( $9C ); { PUSHF -- Push flags } OldIntVec; IF Count = MAX_COUNT THEN Begin Count := 0; ReadPalette; ChngPalette; WritePalette; End ELSE INC( Count ); End; {$F-} BEGIN Count := MAX_COUNT; GetIntVec( $1C, @OldIntVec ); SetIntVec( $1C, Addr( NewTimer ) ); Keep( 0 ); END.
- threeio 11y ago
  Your TurboPascal program just gave me flashbacks to a different time. Thanks.
- white-flame 11y ago
  Usually if one color goes away it's the connector or cable that failed. But in all the VGA cards I had, updating the palette caused a little bit of snow to appear onscreen. Didn't you get the same?
chris_wot 11y ago
Oh my gosh - Space Quest III - my favourite game ever!!!
justinlardinois 11y ago
I love having to hack a little bit to get a game running. (Once in a while, at least.) I remember trying to get SimCity 3000 Unlimited to run on my Windows XP laptop. The laptop was 10 years old, and the game was even older, meant to run on Windows 98 if I remember right. The game refused to run in anything but 16 bit color mode, while 32 bit was the default on XP. I thought maybe I could fiddle with the compatibility options on the shortcut, but all it had was a checkbox to run in 8 bit mode. I could go into XP's graphics options and manually switch to 16 bit mode, but that would be annoying to do every time I wanted to play the game, and then undo it afterwards. I thought maybe I could write a batch script to do it, but Windows XP didn't have anything built in to change the color mode from the command line. Thankfully there's a program out there called QRes that does just that. I wrote a script that switched the color mode to 16 bit, ran SimCity, then waited for it to terminate before switching back to 32 bit. Setting that up was more fun that actually playing the game.
Poyeyo 11y ago
In my case I had a very dark CRT monitor. Likely burned out after many years of use. This is the tool I made to make it brighter: https://github.com/macondobits/gamma https://github.com/macondobits/gamma It resides in the system tray, remembers profiles, and it could be useful for someone else. I will upload the gamma.exe file to github one of these days, or sooner, if anyone wants it. The great and unexpected thing, it even works in Wine and changes the gamma ramp in Ubuntu. I use xgamma in the command line instead of my own tool, but I'm glad it works.
Cpoll 11y ago
Relevant, and explains "business" and "casual" mode quite well: https://news.ycombinator.com/item?id=11366373 https://news.ycombinator.com/item?id=11366373

118 points by duck 11y ago

This was awesome. I feel like there's something lost when devices are locked down so tight that you can't hack on them at a low level (despite whatever risks present themselves). I remember using Norton Disk Editor in the early 90's to fix directory entries (and occasionally break them!). I learned some fantastic lessons about backups and how to recover from mistakes. This is the reason that I'm firmly stuck in the Android camp (on devices that I can root). I'm one a very, very small minority though.

chadzawistowski 11y ago
I echo the sentiment but think Android doesn't go far enough; especially as apps migrate to relying on the closed/proprietary Google Play Services framework rather than vanilla Android. I'm anxiously awaiting the https://neo900.org/ https://neo900.org/
- jrcii 11y ago
  I'm a big fan of this project, too. However I'm disappointed that the final price is going to come out to about $1200 http://neo900.org/estimate http://neo900.org/estimate There seems to be a fair amount of money and attention being invested in secure messaging, Mark Cuban's Cyber Dust, Blackphone, the various things by Moxie's Open Whisper Systems, etc. However the Neo900 as far as I know is the only solution offering a sandboxed baseband which is critical.
  - dTal 11y ago
    The Pyra Console [https://pyra-handheld.com/ https://pyra-handheld.com/] has a sandboxed baseband (in that it's a seperate chip controlled by tty with no direct access to anything), and at 500 Euros to obsolete my netbook and my phone in one go, I will certainly be getting one. Pre-orders should be opening any day now.
    - gr3yh47 11y ago
      What is it going to need to make it function as a phone?
      - dTal 11y ago
        Well, it runs stock Debian- so I imagine either the freesmartphone.org stack or oFono (both packaged), coupled with a relevant user interface. Really the UI is the hard bit, you can send and receive SMS just by cat-ing stuff to the tty device. Ubuntu has a lot of oFono-based UI stuff that can be stolen, though there's quite a few dependencies. Given how the Pandora community rallied around their platform, I've no doubt that we'll end up with a plug-and-play solution before long. Also it'll probably be awkward for phone calls without some sort of headset (or just putting up with speakerphone all the time), but I hardly ever make calls anyway and it'll more than make up for that by being awesome at texting.
- rtkwe 11y ago
  > especially as apps migrate to relying on the closed/proprietary Google Play Services framework rather than vanilla Android. Blame the manufacturers, Google started moving more and more functionality into the services instead of the base OS partially because manufacturers were being so horrible about updating their phones. With functionality in the Services instead of the base OS they can update functions without manufactures deciding that it's not worth their time and holding things back.
  - chadzawistowski 11y ago
    I don't blame anyone, I just find the result undesirable.
justinlardinois 11y ago
> This is the reason that I'm firmly stuck in the Android camp (on devices that I can root). I'm one a very, very small minority though. How do you figure you're a minority? Android has the highest market share of any smartphone OS in most parts of the world, developed or otherwise.
- schoen 11y ago
  Maybe it's that a minority of people currently see the user-modifiability of Android devices as an important benefit, not that a minority of smartphone users use Android.

kazinator 11y ago

> The cruel joke? In business mode, the picture was fine. The problem, whatever it was, manifested itself only in casual mode: the mode all the games used. Curious terminology. A high resolution text mode being stable, but a low-res graphics mode going haywire is almost certainly an issue with the display adapter and not the cathode ray tube.

rzzzt 11y ago
I'd blace my bet on the deflection circuits (horizontal output transistor). I had similar problems with a more recent CRT, where the top right corner of the image started to shake frantically after a few minutes if you switched to high resolution modes. EDIT: It seems I didn't catch any of the details right... the author's display was probably not multisync and developed problems in the low resolution mode. Oh well.
wnoise 11y ago
EGA was "dual-sync": in the 200 line modes, it ran at 15 kHz, whereas the 350 line modes ran at 23 kHz. While it's quite possible that the card had the problem, it's also possible that CRT was the problem. If the components drifted out of spec, it might no longer be able to correctly sync at 15 kHz, especially after warming up.
mikejmoffitt 11y ago
The problems being described sound like capacitors that have gone bad in the deflection circuitry. In the world of arcade machines, which run CRT monitors for hours on end every day, this failure mode is very common, and it shows as a "curl" on one or more sides of the display.
qb45 11y ago
I love those remote debugging sessions :) I have never seen those circuits so can't comment on what could be wrong, but if cooling the monitor helped I think it wasn't EGA's fault. Too bad the OP didn't keep this machine.
Animats 11y ago
The tube itself probably wasn't the problem. Trouble with the electron guns usually means a dead tube, or a dead color. Problems related to sweep are outside the tube. If he had a problem that appeared as overheating, the first thing to try is freeze spray. Find out what component is temperature sensitive. It's probably a capacitor. It's not that hard to work on a CRT unit. You have to discharge the second anode voltage after powering off. (I was once trained to repair analog radios and TVs. This is now a totally useless skill.)

apricot 11y ago

Nice article, but it could have done without the awful monikers "business mode" and "casual mode". I instinctively went for the shift keys fractions of a second after seeing that Sidekick menu.

gtrubetskoy 11y ago

Attempting to take apart a TV set back in my childhood got me a lesson in that just because it's not plugged in, doesn't mean there is no electricity in it, those capacitors pack a punch one never forgets.

girvo 11y ago
I made the same mistake. Once. You certainly don't make that mistake again!

thangalin 11y ago

Many moons ago, my CRT monitor's red gun went kaput. It's easy to imagine what that must have looked like. Anything red appeared as, well, black. Everything else was a shade of cyan, blue, or green. The solution? A TSR, like in the article. The TSR I wrote was simple in comparison: it constantly refreshed the palette. A palette entry with a red value greater than zero had its blue and green values increased accordingly. The red component was then zeroed out. Necessity is a powerful impetus for spurring creativity in frugal college students. This looks to be an earlier version, as it doesn't increase the blue and green values, but gives an idea of how it worked: {$M 1024,0,0 } { 1K stack, no heap } USES Crt, DOS; CONST MAX_COUNT = 384; READ_PAL = $3C7; WRIT_PAL = $3C8; RED = 1; GRN = 2; BLU = 3; VAR OldIntVec : PROCEDURE; NoRed : ARRAY[ RED..BLU, 0..255 ] OF BYTE; Count : INTEGER; Colour : BYTE; PROCEDURE ReadPalette; Begin FOR Colour := 0 TO 255 DO Begin Port[ $3C7 ] := Colour; NoRed[ RED, Colour ] := Port[ $3C9 ]; NoRed[ GRN, Colour ] := Port[ $3C9 ]; NoRed[ BLU, Colour ] := Port[ $3C9 ]; End; End; PROCEDURE ChngPalette; Begin FOR Colour := 0 TO 255 DO IF NoRed[ RED, Colour ] <> 0 THEN NoRed[ RED, Colour ] := 0; End; PROCEDURE WritePalette; Begin FOR Colour := 0 TO 255 DO Begin Port[ $3C8 ] := Colour; Port[ $3C9 ] := NoRed[ RED, Colour ]; Port[ $3C9 ] := NoRed[ GRN, Colour ]; Port[ $3C9 ] := NoRed[ BLU, Colour ]; End; End; {$F+} PROCEDURE NewTimer; INTERRUPT; Begin InLine( $9C ); { PUSHF -- Push flags } OldIntVec; IF Count = MAX_COUNT THEN Begin Count := 0; ReadPalette; ChngPalette; WritePalette; End ELSE INC( Count ); End; {$F-} BEGIN Count := MAX_COUNT; GetIntVec( $1C, @OldIntVec ); SetIntVec( $1C, Addr( NewTimer ) ); Keep( 0 ); END.

threeio 11y ago
Your TurboPascal program just gave me flashbacks to a different time. Thanks.
white-flame 11y ago
Usually if one color goes away it's the connector or cable that failed. But in all the VGA cards I had, updating the palette caused a little bit of snow to appear onscreen. Didn't you get the same?

chris_wot 11y ago

Oh my gosh - Space Quest III - my favourite game ever!!!

justinlardinois 11y ago

I love having to hack a little bit to get a game running. (Once in a while, at least.) I remember trying to get SimCity 3000 Unlimited to run on my Windows XP laptop. The laptop was 10 years old, and the game was even older, meant to run on Windows 98 if I remember right. The game refused to run in anything but 16 bit color mode, while 32 bit was the default on XP. I thought maybe I could fiddle with the compatibility options on the shortcut, but all it had was a checkbox to run in 8 bit mode. I could go into XP's graphics options and manually switch to 16 bit mode, but that would be annoying to do every time I wanted to play the game, and then undo it afterwards. I thought maybe I could write a batch script to do it, but Windows XP didn't have anything built in to change the color mode from the command line. Thankfully there's a program out there called QRes that does just that. I wrote a script that switched the color mode to 16 bit, ran SimCity, then waited for it to terminate before switching back to 32 bit. Setting that up was more fun that actually playing the game.

Poyeyo 11y ago

In my case I had a very dark CRT monitor. Likely burned out after many years of use. This is the tool I made to make it brighter: https://github.com/macondobits/gamma https://github.com/macondobits/gamma It resides in the system tray, remembers profiles, and it could be useful for someone else. I will upload the gamma.exe file to github one of these days, or sooner, if anyone wants it. The great and unexpected thing, it even works in Wine and changes the gamma ramp in Ubuntu. I use xgamma in the command line instead of my own tool, but I'm glad it works.

Cpoll 11y ago

Relevant, and explains "business" and "casual" mode quite well: https://news.ycombinator.com/item?id=11366373 https://news.ycombinator.com/item?id=11366373