Today I dumped the PAL from an original Juno First PCB.PAL is at location B6 of lower board, part name is scratched off but schematics reports it as a PAL10L8.Dump has been tested as working in a GAL16V8 targeting device.
Today we have some new PAL dumps from the following boards:
All dumps have been tested and working in GAL targeting devices.
Hi there !
FD1089A version of Outrun Deluxe Sitdown (317-0019) is now available , you can grab it from the dedicated page.
Cheers !
I got this Truxton PCB (export version of Tatsujin) in a recent operator raid:
Once powered it up board showed GFX issue, the sprites were blocky :
Besides, there was some kind of video interference, this is a common issue on this board and usually it’s due capacitors in the audio section, indeed I found a 470uF 16V one with bad capacitance :
Back to the sprites issue, relevant data are stored in four 1Mbit 28 pin MASK ROMs :
I went to dump them and found a faulty one:
Replacing it with one from a donor board didn’t fix the issue therefore I went on in my troubleshooting.Each data bit of the sprites MASK ROMs is fed into inputs of four 8-bit 74LS166 register.I probed them with my logic comparator and led on output pin 13 lit for two of them:
I desoldered the ICs:
They both failed the out-out-circuit testing (obviously they were from Fujitsu) :
Sprites were fully restored :
The last issue I had to fix was that Player 1 Start input didn’t work.The inputs circuitry was previously reworked by someone (note the replaced 74LS240 and some patched traces)
I traced Player 1 Start back from pin 17 parts side of JAMMA connector to an end of a 220 Ohm resistor @R17 whose other end was tied to pin 13 of the 74SL240 @21K :
Signal on pin 17 of the JAMMA connector and on first end of the resistor was high and correctly toggling when pressing the button while was totally missing on pin 13 of the 74LS240.Therefore the only culprit had to be the resistor.Indeed I got no reading measuring it on circuit:
I removed and tested the resistor out-of-circuit having confirm it was opened:
Job done.
When switching ON the game, sometimes it had very fast tempo music.
It happened 1 one out of 10 but it was very annoying.
So I used my frequency counter when it happened and I noticed that the 3.58mhz quartz ran at about 10.58mhz!
I changed it with a know good one but again it happened very often.
I was sure it was something connected to the quartz oscillator circuit and given that the resistances are difficult to be faulty I decided to change the cap C47 (33pF) with known good one.
After testing about 30 cycles of switching on and off the game didn’t develop again the problem
Game fixed.
