Which chips are the SRAM? I don't have a hot air station but I guess I could lift them off leg-by-leg like I did with MVS BIOS and solder new ones in if they still are available. I can also trace the other GAL if new SRAM won't fix the issue.
- Thread starter nassekova
- Start date
Yes. Though the connection is most likely going to one of the logic chips, instead of the SRAM directly.
I expect most connections go to the cartridge edge and U8.
Ok, here we go again!
I measured the u15 and the results are in the picture. I started to wonder why there was 0 connections to SRAM and it seems that u14 is the one that connects to SRAM! So updatet those SRAM connections to u14 too.
Here is what I got out of u15. Arrows are again on the other side of the cartridge edge. It also connected to u14 two times.
And here are those SRAM connections from the u14. I just draw them to one of the chips since they seem to share the connections.
I measured the u15 and the results are in the picture. I started to wonder why there was 0 connections to SRAM and it seems that u14 is the one that connects to SRAM! So updatet those SRAM connections to u14 too.
Here is what I got out of u15. Arrows are again on the other side of the cartridge edge. It also connected to u14 two times.
And here are those SRAM connections from the u14. I just draw them to one of the chips since they seem to share the connections.
Let's see if I can translate that into a pinout:
U14:
2 TA18
3 TA19
4 TA20
5 TA21
6 TA22
8 U20 ~OE
10 U15 Pin 8
12 GND
14 INT_T_ROM_OE
15 T_ROM_OE
16 I_TA18
17 I_TA19
18 I_TA20
19 I_TA21
21 U15 Pin 7
24 VCC
U15:
1 AS
2 PA16
3 PA23
4 PA22
5 PA21
6 PA20
7 U14 Pin 21
8 U14 Pin 10
12 GND
20 U8 A19
22 U8 OE
23 INT_P_ROM_OE
24 VCC
Are you sure about the one that goes from U14 Pin 8 to U20 Pin 22? Both should be inputs, so connecting them together doesn't do anything, unless they are connected to another output somewhere.
Also, what about U14 Pin 10 to U15 Pin 8? Both are inputs as well. (Pins 1-11 and 13 of a 22V10 are hardwired as inputs, the rest can be inputs or outputs.)
U14:
2 TA18
3 TA19
4 TA20
5 TA21
6 TA22
8 U20 ~OE
10 U15 Pin 8
12 GND
14 INT_T_ROM_OE
15 T_ROM_OE
16 I_TA18
17 I_TA19
18 I_TA20
19 I_TA21
21 U15 Pin 7
24 VCC
U15:
1 AS
2 PA16
3 PA23
4 PA22
5 PA21
6 PA20
7 U14 Pin 21
8 U14 Pin 10
12 GND
20 U8 A19
22 U8 OE
23 INT_P_ROM_OE
24 VCC
Are you sure about the one that goes from U14 Pin 8 to U20 Pin 22? Both should be inputs, so connecting them together doesn't do anything, unless they are connected to another output somewhere.
Also, what about U14 Pin 10 to U15 Pin 8? Both are inputs as well. (Pins 1-11 and 13 of a 22V10 are hardwired as inputs, the rest can be inputs or outputs.)
I will double check those two after work today but I am pretty sure they were connected (unless I mistakenly draw them to wrong places, but I doubt). I can also check if they (U14 pin 8 and pin 10) are connected to some edge or EPROM or BIOS too.
- U14 Pin goes to U20 Pin 21, not 22! (it is 7th pin from the right, at least I tried to point it in there
).- U14 Pin 10 to U15 Pin 8 connects. I then traced where they connect and it seems to be this X6 chip. Here is a picture where it goes in there.
I didn't have time to look at this right now... I was planning to get out one of my other cartridges to see if the ASIC pin is connected somewhere.
I guess even in the worst case that the ASIC is fried someone is going to work out how to make the game work without it, and you can resurrect the cart just with a new EPROM.
I guess even in the worst case that the ASIC is fried someone is going to work out how to make the game work without it, and you can resurrect the cart just with a new EPROM.
Yea sure. Didn't meant to sound ungrateful or hurry you, I know you guys have other things on your plate too. It is just taking some of my work space so I will pack that cartridge from my desk now and when ever you or anyone else with the know-how gets a time to look on this matter just post here and I will continue with it 
Did this got any good ending?
Asking because I recently swapped new caps to my Bee Storm and now all I get is the normal start up routine and then black screen. There was some flakiness in the cart before, but now it completely refuses to start up.
Asking because I recently swapped new caps to my Bee Storm and now all I get is the normal start up routine and then black screen. There was some flakiness in the cart before, but now it completely refuses to start up.
Uroko Sakanabito
Grand Master
Yes, please continue! Pretty interesting read here 
I got my jig working again, though so far I've got only a working FN_U15. The FN_U14 I made just crashes with an ASIC error. I'll have to check tomorrow if one of the io pins is used as input or tristate, or if I just made a bad dump.
Edit: Be careful with ATF22V10, they have a different programming algorithm than other GAL, and my programmer enables a power save feature. Lattice 22V10 should work, though you can only get new-old-stock.
Edit: Be careful with ATF22V10, they have a different programming algorithm than other GAL, and my programmer enables a power save feature. Lattice 22V10 should work, though you can only get new-old-stock.
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Yeah we tried a few more things with atf22v10 and still haven't gotten them to work perfectly with some of our multis.
