That would be a tremendous help!
Thank you....
Thank you....
-
Please post all monitor technical topics in the Technical - Videogames - Monitors section, not in the General Help section.
Midway clowns and 2716's
- Thread starter wrongdon
- Start date
Test ROM is attached. Be aware it's a rough conversion from the SI ROM and tests RAM and the shifter - it will appear to test sounds but I can't remember if I fully tested that part (as I wasn't having problems with the sound on mine) and the sound labels displayed are incorrect (unchanged from SI)
Burn to a 2716 and fit in the EPROM position nearest to the PCB Midway logo
If you haven't already worked out the 2716 strapping I'll post up photos of my board
Burn to a 2716 and fit in the EPROM position nearest to the PCB Midway logo
If you haven't already worked out the 2716 strapping I'll post up photos of my board
This is great - thank you!
I still have not strapped for the 2716's as I was hoping that the test ROM was 2708 and I would be able to find the culprit should one be bad - but taking into consideration that (just checked) I cannot burn a 2708 I guess I will need to go to the larger EPROM anyway....
So..... if you could please take a pic of your 2716 strapping I would appreciate it.
Thank you for taking the time to help a brother out!
Jeff
I still have not strapped for the 2716's as I was hoping that the test ROM was 2708 and I would be able to find the culprit should one be bad - but taking into consideration that (just checked) I cannot burn a 2708 I guess I will need to go to the larger EPROM anyway....
So..... if you could please take a pic of your 2716 strapping I would appreciate it.
Thank you for taking the time to help a brother out!
Jeff
Here is the strapping for 2716
Photo 1 shows S1-S5, photo 2 shows S6 and photo 3 shows a wider view of their position on the board. The test ROM needs to go where "CL1" is. And yes, the board needs a good clean
Photo 1 shows S1-S5, photo 2 shows S6 and photo 3 shows a wider view of their position on the board. The test ROM needs to go where "CL1" is. And yes, the board needs a good clean
wugly
Well-known member
just document how to undo it if you are not going to burn new roms
Lurch666
Well-known member
Don't forget to remove all of the 2708 eproms when you restrap and use a 2716 test rom as a board strapped for 2716 will probably kill 2708s.
I'll burn the test ROM and give it a go first thing tomorrow,,,,, post the results thereafter.....
Thanks for all the help.
Jeff
Thanks for all the help.
Jeff
If there were bad RAMs would that produce black bars?
If that's the display you're getting when running the test ROM it's not right. You should get various test patterns on the screen followed by inputs/sounds text displayed
I have the Test ROM in socket H and that is the display I am getting......
In the mean time as I thought that was correct I concatenated the files by using the copy /b Command
copy /b C.bin + D.bin NewF.bin CHKSUM=87D9
copy /b E.bin + F.bin NewG.bin CHKSUM=1ACB
copy /b G.bin + H.bin NewH.bin CHKSUM=BB9B
Before I go and burn these, do these ChkSums look good?
Thanks again
Jeff
In the mean time as I thought that was correct I concatenated the files by using the copy /b Command
copy /b C.bin + D.bin NewF.bin CHKSUM=87D9
copy /b E.bin + F.bin NewG.bin CHKSUM=1ACB
copy /b G.bin + H.bin NewH.bin CHKSUM=BB9B
Before I go and burn these, do these ChkSums look good?
Thanks again
Jeff
Do I need to put the second file first when combining these files, I am thinking that I read that somewhere......
wugly
Well-known member
do you get the same pattern with no roms installed?
That's the pattern with the test ROM and no other ROMs installed.....
I'll pull that one and fire it up and see what I see.....
I'll pull that one and fire it up and see what I see.....
wugly
Well-known member
I don't want to go out on a limb but that pattern looks a lot like no program running and bad rams
I pulled the test ROM and fired it up. Received the attached display. It's not static as it kinda shifts every so often:
Attachments
As @wugly mentioned above that looks like the programme isn't running. Can't say RAMs are bad at this stage as you can't predict what they'll contain on boot. The moving pattern I guess is the watchdog kicking it every few seconds.
One good thing, your checksums for the 2716 ROM images look correct.
You need to check the basics now:-
+5v, +12v, -5v
RESET signal at the 8080 on power up
Clock looks ok as you're getting something on the screen
Check CPU address bus output through AND gates
Check ROM select 7442 at E2 (with the test ROM in place only that ROM select should change)
Check status word latch 74174 at D7
Then it's on to the 153's and 8216's which may be more difficult to test
One good thing, your checksums for the 2716 ROM images look correct.
You need to check the basics now:-
+5v, +12v, -5v
RESET signal at the 8080 on power up
Clock looks ok as you're getting something on the screen
Check CPU address bus output through AND gates
Check ROM select 7442 at E2 (with the test ROM in place only that ROM select should change)
Check status word latch 74174 at D7
Then it's on to the 153's and 8216's which may be more difficult to test
Thank you for confirming my ROM Images.....
I am using the AS Switching P/S adapter so hopefully the reset signal is there but I will check to verify.
I'll get out the schems and start on the list and thank you again for the guidance, hopefully I get this baby going again.
Jeff
I am using the AS Switching P/S adapter so hopefully the reset signal is there but I will check to verify.
I'll get out the schems and start on the list and thank you again for the guidance, hopefully I get this baby going again.
Jeff
