Double Dragon PROM help

Jacmar

Jacmar

Active member
vacBacker
Feedback
1 (100%)
Credits
861CR
So I picked up a bit of a beat up (no pun intended) technos double dragon recently which has a few obvious (and probably a whole heap of unobvious) issues, but one of the main ones is it's missing IC101 - the PROM chip which handles the priority of the graphics layers I think.

Just wondering what's peoples opinions on the best option here to replace this bipolar prom? The options I know about are...

1) Find and buy some Fujitsu MB7114 compatible PROM chips and ask a kind hearted individual with the capabilities to burn bipolar proms to help me out (for a fee of course)..
2) Knock up a replacement using a PROM adapter and EEPROM. I do have some of these adaptor boards form PhilMurr who very kindly sent me some recently but would have to buy some Winbond 27C512 EEPROMs I think as they are the fast ones? (do you have to alter the PROM file in any way to burn it to the EEPROM though?)
3) I think there may be a way of using a GAL chip and converting the PROM file to a jed file? this is the one I know least about and what parts/software I would need ...
4) another option I don't know about ?
Cheers
 
ExZX

ExZX

Active member
Feedback
35 (100%)
Credits
1,764CR
Test the other parts first? Dump and verify proms, test RAM, 68000, z80. Anything socketed that can be tested.
Am guessing it's the one off ebay covered in rust with previous repairs? Unlikely it'll do much even with that missing part replaced. You're best asking if someone has a spare from a parts board they can loan / give you. Very common board.
 
Jacmar

Jacmar

Active member
vacBacker
Feedback
1 (100%)
Credits
861CR
Yeah I get all that and I will test all those things of course, I was just wondering what the best option is for when I get to that point, as no doubt I'll come across a missing/knackered PROM again at some point so might as well start building the knowledge now so I have it when I need it (y)
I'll probably try the adapter option first as it seems the easiest to begin with and I have some, but was also wondering if there was an option I didn't know about.
cheers
 
You must log in or register to reply here.
Top