Atari 800: Part 2

Channel:

The Clueless Engineer

Subscribers:

3,280

Published on February 7, 2023 1:30:26 AM ● Video Link: https://www.youtube.com/watch?v=fIjrMqNlzCI

Duration: 35:14

209 views

20

Gave the case a good clean & scrub - came up nice. I also stripped and gave the keyboard a good wash - feels quite nice to use. No sticky keys anymore.

I did notice one issue that will cause me issues ... two of the pins in the PERIPHERAL (SIO) port were bent - trying to fix caused one to break ... 😣

The power board generates +12VDC, +5VDC, and -5VDC so I really do need to use an AC power supply rather than a DC supply.

I don't have a 9VAC power supply handy so might make a simple one with a toroidal transformer. In the meantime I'm going to use a (*gasp*) 🫣 Commodore VIC-20 supply from the US that is otherwise useless to me.

So I merrily chopped off the connector and soldered on a 2.5mm plug.

The Atari power supply board seems to work nicely! So I started replacing the electrolytic capacitors ... got stuck with the three-legged 4700µF dual capacitors ... can I just use a normal capacitor? One of the dual capacitors has two legs connected to +VE and one to GND, and the other has two connected to GND and one to +VE.

The schematic (p53) shows CR207 & CR208 as simply 4700µF ... so that's what I'll do. Interesting to note they are labelled CR207 instead of C207 ... the R is to indicate they are related to the Rectifier?

http://www.atarimania.com/documents/Atari_400_800_Field_Service_Manual_June_82.pdf

Part 1:
https://youtu.be/Bq564VngsNc

Part 3:
https://youtu.be/wgbqldsGHVo

Part 4:
https://youtu.be/_yAadoDELjs