Jump to content
IGNORED

1200XL Slow to Boot


gilsaluki

Recommended Posts

 

Additional information: The SIO works, load disk programs from 1050 drive. One more anomaly will happen from time to time. When starting a game such as Galaxian, some of space items are huge! I mean double the normal size. I push RESET and everything is back to normal.

 

 

 

The fact that SIO works means your POKEY is probably fine. The weird sprites make me think GTIA or less likely ANTIC.

Link to comment
Share on other sites

OK - RESET looks OK.

 

After RESET, the clocks have to be running, CPU has to work, MMU is required, and the OSROM has to be OK.

 

Clocks need GTIA.

 

Black screen means that the CPU has not written to ANTIC/GTIA, which it does early in the power-on sequence.

 

Try the above chips. Gets tougher after that...

 

Bob

Link to comment
Share on other sites

Looks like it is the GTIA Chip: C014805. Swapped it from my 600XL. Now boots as it should. This has been interesting. I did learn a lot about the 8-bits, so I guess that is good. Anyone know where I can get a replacement GTIA Chip NTSC C014805?

Thanks for ALL the assistance. Couldn't keep these machines running w/o everyone's help.

  • Like 5
Link to comment
Share on other sites

Looks like it is the GTIA Chip: C014805. Swapped it from my 600XL. Now boots as it should. This has been interesting. I did learn a lot about the 8-bits, so I guess that is good. Anyone know where I can get a replacement GTIA Chip NTSC C014805?

Thanks for ALL the assistance. Couldn't keep these machines running w/o everyone's help.

 

 

Glad you got it sorted out! B&C (MyAtari on eBay) and Best Electronics still has these, last I had heard.

Link to comment
Share on other sites

Looks like it is the GTIA Chip: C014805. Swapped it from my 600XL. Now boots as it should. This has been interesting. I did learn a lot about the 8-bits, so I guess that is good. Anyone know where I can get a replacement GTIA Chip NTSC C014805?

Thanks for ALL the assistance. Couldn't keep these machines running w/o everyone's help.

 

Great news! Best Electronics comes to mind or you might try http://www.80svc.com/

Link to comment
Share on other sites

Ordered as GTIA from Best. Ordered some other needed items. If I already didn't drink, this computer would have driven me to it. I went back to turn it back on, after using it just one hour before; nope it would not come up. Yes the Power Light LED was on but the screen just showed snow. Oh no! Now no boot at all! I have been noticing the heat sink (large heat L-shaped heat sink in the rear had been getting rather warm. I thought maybe the two inverters mounted to it were overheating. So, apart the 1200XL came once again (this is about the 30th time in the past several days). Luckily I had some thermal paste from when I repaired my son's original PS3 (YLOD) overheating problem. I cleaned off the 35 year old white paste and applied a fresh coat of thermal paste. It boots now, normally and the heat sink is cooler, I believe. The jury is still out whether or not I have finally solved all its issues. Plays well at this moment. Man, these machines are a challenge.

Link to comment
Share on other sites

Ordered as GTIA from Best. Ordered some other needed items. If I already didn't drink, this computer would have driven me to it. I went back to turn it back on, after using it just one hour before; nope it would not come up. Yes the Power Light LED was on but the screen just showed snow. Oh no! Now no boot at all! I have been noticing the heat sink (large heat L-shaped heat sink in the rear had been getting rather warm. I thought maybe the two inverters mounted to it were overheating. So, apart the 1200XL came once again (this is about the 30th time in the past several days). Luckily I had some thermal paste from when I repaired my son's original PS3 (YLOD) overheating problem. I cleaned off the 35 year old white paste and applied a fresh coat of thermal paste. It boots now, normally and the heat sink is cooler, I believe. The jury is still out whether or not I have finally solved all its issues. Plays well at this moment. Man, these machines are a challenge.

The 1200XL doesn't have any inverters, these are used to convert DC to AC.

 

It has a full bridge rectifier and a 2 * 7805 voltage regulators to convert 9VAC to 5VDC. Flashjazzcat has modified a 1200XL to use an external 5VDC power supply, eliminating these and the heatsink. This modification made room for a PBI connector.

  • Like 1
Link to comment
Share on other sites

A PBI connector will also fit on the right side of a 1200XL with only minimal modification of the heat sink. I had planned to do this, but I couldn't find a way of attaching the PBI connector that suited me. I did measure, and it will fit, if you can find a way of attaching a connector to the board.

 

Maybe a small daughterboard with card edge connector mounted with standoffs in some strategically drilled holes above the 1200XL motherboard?

 

Just an idea :)

Link to comment
Share on other sites

The 1200XL doesn't have any inverters, these are used to convert DC to AC.

 

It has a full bridge rectifier and a 2 * 7805 voltage regulators to convert 9VAC to 5VDC. Flashjazzcat has modified a 1200XL to use an external 5VDC power supply, eliminating these and the heatsink. This modification made room for a PBI connector.

Thanks for the clarification. I wasn't sure what those two devices were. I know the heat sink would get pretty warm, if not hot. Hopefully this darned thing will act correctly now. Again, thanks to all for their assistance.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...