gregf |
Ramtek's Trivia promoter
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Reged: 09/21/03
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Posts: 8615
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Loc: southern CA, US
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Re: Senseless connection?
01/01/10 11:27 PM
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------ In the schematics of Atari Space Race (http://discrete.mameworld.info/Atari/Spacerace/SpaceRace.pdf) there is on the second sheet in the area A/B and 3/4 a net of 4 connections to only inputs of gates. F3 pin 2+3, D4 pin 9 and H1 pin 1.
Does anyone have an idea what could be missing here? A signal name or a connection - to what signal?
My best guess is that the carry output of E5 (pin 15) should go to this net, while it seems unlikely the little piece of line was missed. Any other ideas? -------------
I forgot that the schematics I have are blue print copies of the actual hand-drawn (first version print?), but thankfully E5 (pin 15) shows the connection compared to Atari's reprinted schematics.
The E5 (ic 9316) is the same for both Space Race and Asteroid schematics.
Going over schematics here on hand.
---------- On Atari Space Race schematics (Al's hand drawn schematics): The ic 9316 E5 (pin 15) connection appears to lead to 6th pin? (IC 7402) E4 on on pcb.
On Midway Asteroid schematics: The ic 9316 E5 (pin 15) connection appears to lead to 3rd pin? (IC 7402) F3 on pcb. ---------
Taking another look at the current online (second reprint?) of Space Race schematics, they look closer to Midway Asteroid schematics compared to the hand drawn, original first draft print of Atari Space Race schematics.
Edited by gregf (01/01/10 11:39 PM)
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