I opened up a super nintendo import adaptor today. Its the kind where you plug in two cartridges and one acts as the lockout chip donor. What I noticed is that the lines passing trough the "extra" pins the super fx chip/super gameboy use are cut. One line has been "fixed" with wire..and interestingly enough super fx games DO work using it...anyone have an idea why they might've done this?
super fx does not need the those extra pins. don't know why they are cut though
I recall hearing that it DOES need one of the pins (the clock iirc)
edit: in fact checking the adaptor vs a pinout it seems the clock is the thing that they connected. (also the audio in lines are not connected thanks to this so that explains the lack of sound i'm getting)
edit: in fact checking the adaptor vs a pinout it seems the clock is the thing that they connected. (also the audio in lines are not connected thanks to this so that explains the lack of sound i'm getting)
If I remember well on Super FX PCBs one of the extra lines is simply grounded or something like that. Maybe the SGB actually uses them tough I'm not sure either.
Well the super gameboy needs A clock...and it gets this of the snes. But then it wouldnt work at all..(and that line happens to be connected...cant fix audio either...dont have any f-ing solder)
edit: I got the sound working...I bridged the points with some solder (dont ask how I managed to get the solder)
edit: I got the sound working...I bridged the points with some solder (dont ask how I managed to get the solder)
Jeroen wrote:
I opened up a super nintendo import adaptor today. Its the kind where you plug in two cartridges and one acts as the lockout chip donor. What I noticed is that the lines passing trough the "extra" pins the super fx chip/super gameboy use are cut. One line has been "fixed" with wire..and interestingly enough super fx games DO work using it...anyone have an idea why they might've done this?
You might want to read the "Background" section in Mark Knibbs' excellent Tri-Star Super Gameboy Fix document. It gives an explanation about why in many pieces of third-party hardware, pin 1 of the SNES connector was cut.
mmmmmmm I see. Well I connected some more lines, the /wram and refresh) its stil glitchy...but I think this is due to the improv soldering job I had to do.
Jeroen wrote:
I recall hearing that it DOES need one of the pins (the clock iirc)
nope, it's not needed by the superfx, perhapse some games uses it. neither stunt race nor vortex uses it though
starfox does. (only game that does iirc) Anyway I fixed EVERY line...its stil glitchy. I think the adaptor is adding line interference or something.
edit: video time...note that the problem was MUCH worse before I fixed those lines.
edit: video time...note that the problem was MUCH worse before I fixed those lines.
Are you sure ? I once disassembled my Starfox card and I was pretty sure only one pin was grounded or something like that. Same for Yoshi's Island.
Bregalad wrote:
Are you sure ? I once disassembled my Starfox card and I was pretty sure only one pin was grounded or something like that. Same for Yoshi's Island.
Starfox does use pin1, it's connected to L1 (ferrite bead), then to 3 pin on a small ic (might be an inverter or buffer) then to pin 70 on the sfx (CLK), pin 70 is also connected to a resistor (1kOhm) to ground
so yes it's used on that one
Something I've been wondering...
Either the clock signal available at the cartridge connector is too dirty to use, or it "stops" during refresh like the trace in ikari_01's post at the start of this page:
http://nesdev.com/bbs/viewtopi ... 7&start=45
If it does indeed stop during DRAM (WRAM) refresh, that's some serious loss of calculation time, and no wonder later games used their own cheapie hex-inverter and resonator based oscillator.
Just a speculation.
Either the clock signal available at the cartridge connector is too dirty to use, or it "stops" during refresh like the trace in ikari_01's post at the start of this page:
http://nesdev.com/bbs/viewtopi ... 7&start=45
If it does indeed stop during DRAM (WRAM) refresh, that's some serious loss of calculation time, and no wonder later games used their own cheapie hex-inverter and resonator based oscillator.
Just a speculation.