Whoops, I did it again. I have a problem, Dragon 32 inbound

[stephen_usher]

I do wonder if the Dragon will drive you CoCo.

[rubber_jonnie]

It's heeeeeeeere

A bit grubby, but that's quite normal for this stuff, so OK with that:

PXL_20220331_110548216.jpg (360.58 KiB) Viewed 1902 times

Looks better now for a quick clean.

Interestingly, 3 out of 4 stickers stating that the guarantee is void if broken are still intact, so I don't think anyone has opened it:

PXL_20220331_115424358.jpg (255.42 KiB) Viewed 1902 times

I may even try to preserve the stickers when I open it up.

Next I need to look over the PSU.

[stephen_usher]

I hope it's all OK. Having an unopened machine is nice. This is why I'm in two minds about opening up and modding the C64.

[rubber_jonnie]

I hope it's all OK. Having an unopened machine is nice. This is why I'm in two minds about opening up and modding the C64.

Which is why I want to be careful with the stickers when I do open it up. Given how grubby it was, I think I really need to open it up and make sure it's not got any mice, spiders or other creatures nesting in it!!.

[stephen_usher]

I hope it's all OK. Having an unopened machine is nice. This is why I'm in two minds about opening up and modding the C64.

Which is why I want to be careful with the stickers when I do open it up. Given how grubby it was, I think I really need to open it up and make sure it's not got any mice, spiders or other creatures nesting in it!!.

Maybe it has more hamsters inside, making faster?

[rubber_jonnie]

Which is why I want to be careful with the stickers when I do open it up. Given how grubby it was, I think I really need to open it up and make sure it's not got any mice, spiders or other creatures nesting in it!!.

Maybe it has more hamsters inside, making faster?

You never know!!

[rubber_jonnie]

Hmm, quick check and the 'do not remove' labels are very fragile, they may need to be warmed if I stand any chance of peeling them.

In other news, I need to go get the Dragon schematics, for some reason the PSU delivers both 8.5v and 28v (Both AC) and I'd like to know what the 28V is used for.

[stephen_usher]

You may be able to float the stickers off with IPA

[stephen_usher]

Re: PSU.

This may help: http://dragon32.info/info/psu.html

Code: Select all

Power Regulator Board to Main Board Ribbon

                  Power Connector
 _______________++++_____________________
|                                        |
| Modulator                              |
|                            Heatsink    |
|      ^^^^                              |
|______|||||||||_________________________|   (Unconventionally, 9 is the
       987654321                              marked strand.  Numbering
 ______|||||||||_________________________     convention matches the
|      |||||||||                         |    circuit diagrams and PCBs)
|            vvv                         |
|                                        |
|                                        |

 Pin  Direction  Function

  9       ^      Composite Video to modulator
  8       ^      +5V supply to modulator (linked from pin 2 via main board)
  7       ^      Sound to modulator and monitor socket
  6       ^      Composite Video to monitor socket
  5              Ground
  4              Ground
  3       v      -5V (D32) or -12V (D64)
  2       v      +5V
  1       v      +12V

D64 power regulator PCBs have a -12V regulator (7912) fitted for the RS232 port instead of a -5V (7905) originally fitted to the D32s. A small -5V regulator is used on the D64 main board for the video circuit. 

The 28V is probably for the +12V, after rectifying and regulating.

[rubber_jonnie]

You may be able to float the stickers off with IPA

Worth a go for sure.