Jump to content
  • 0
IGNORED

Space Invaders Deluxe, on the bench…


Geekfix1706
 Share

Question

I have a few questions relating to this board set, I’ve researched loads of places and for one piece of info found no answer. 
 

1, Will this game run with bad RAM? This board has had a total RAM swap, no horizontal lines with ram H out, just unsynced blocks and long dots, Game does run but display is a mess, tried both original and latest RAM TEST progs, have pics if anyone would like to see. 
odd that original test only displays anything if I swap the 9310 aka 74LS160 (C7) for a LS163..

2, in the midway 8080 standardised test procedure it mentions Frequency’s at C7 pins 14-11 are they correct.

also in same a list of freq for the 74LS161 chain D5,E5,E6,E7 again are they correct, should note that the bottom set 60Hz, 120Hz, 240Hz, 490Hz are all correct, at the top I don’t get 245Khz I get 312KHz..

 

any help info greatly appreciated 

Ta! 
Pete 

 

Link to comment
Share on other sites

0 answers to this question

Recommended Posts

There have been no answers to this question yet

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

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