2 replies to this topic

[27ace27]

I am using this schematic of the PONG arcade system, http://www.atarihq.c...ngSchematic.pdf , but have some questions. do the resistors like the one on the HSYNC board hooking up to +5V have any specific value? there isn't one on any schematic I can find.

[atarifan49]

27ace27, on Tue Mar 9, 2010 10:31 PM, said:

I am using this schematic of the PONG arcade system, http://www.atarihq.c...ngSchematic.pdf , but have some questions. do the resistors like the one on the HSYNC board hooking up to +5V have any specific value? there isn't one on any schematic I can find.

Those resistors are pull-up resistors. They are holding the particular inputs at a logic high level. Pull-up resistors usually range in value from 1k ohm to upwards of 10k ohms. You can safely use 2.2k or 2200 ohm (red-red-red-gold - 4band, red-red-black-brown-gold - 5band).

Glenn

[27ace27]

atarifan49, on Thu Mar 18, 2010 6:50 PM, said:

27ace27, on Tue Mar 9, 2010 10:31 PM, said:

I am using this schematic of the PONG arcade system, http://www.atarihq.c...ngSchematic.pdf , but have some questions. do the resistors like the one on the HSYNC board hooking up to +5V have any specific value? there isn't one on any schematic I can find.

Those resistors are pull-up resistors. They are holding the particular inputs at a logic high level. Pull-up resistors usually range in value from 1k ohm to upwards of 10k ohms. You can safely use 2.2k or 2200 ohm (red-red-red-gold - 4band, red-red-black-brown-gold - 5band).

Glenn

Thank you very much! that is exactly what I needed.