ChanServ changed the topic of ##yamahasynths to: Channel dedicated to questions and discussion of Yamaha FM Synthesizer internals and corresponding REing. Discussion of synthesis methods similar to the Yamaha line of chips, Sound Blasters + clones, PCM chips like RF5C68, and CD theory of operation are also on-topic. Channel logs: https://freenode.irclog.whitequark.org/~h~yamahasynths
<Lord_Nightmare>
ej5: from your twitter thread: one of the zorro slots is badly mangled, and the pins from opposite sides of the slot could be shorting together
<Lord_Nightmare>
you may need to desolder that entire slot before the a2000 will boot
<Lord_Nightmare>
that slot connector is gonna need to be replaced anyway, so may as well desolder it and eliminate it as a possible problem source
<Lord_Nightmare>
zorro slot 1
<Lord_Nightmare>
cn605
<ej5>
thanks
<Lord_Nightmare>
(sorry, i didn't see you reply here, so i tweeted effectively the same thing as a reply)
<ej5>
slot looks ok.
<Lord_Nightmare>
it might be possible to salvage the intact part of the mangled zorro connector assuming you can get a connector with the same pin pitch but shorter and cut the damaged part off of the zorro connector
<Lord_Nightmare>
and solder the intact part, plus a fragment of the other connector in place
<Lord_Nightmare>
though best would be to just replace the connector with an NOS or salvaged-from-ruined-amiga part
<ej5>
i'll look into it once i get the thing to boot
<ej5>
there's a weird issue where it freezes right before displaying the disk logo (screen is white)
<Lord_Nightmare>
if a card got twisted... hmm. can you check in the slot for any pcb fragments from a card that got its slot connector snapped off in the incident that damaged the connector?
<ej5>
yes it's clean
<Lord_Nightmare>
i'm also worried that the force required to break the connector like that could have damaged traces that are hidden under the connector body
<Lord_Nightmare>
which chip on the amiga is responsible for DMA stuff? paula?
<Lord_Nightmare>
I'm just throwing out random ideas at this point
<ej5>
agnus
<Lord_Nightmare>
the corroded pins on the 68k are probably from the nicad battery exploding
<Lord_Nightmare>
so i'd check for eaten traces around there
<ej5>
yeah those are mostly data lines and they are (oddly enough) ok
<ej5>
but i should probably check to see if they go to devices other than just the ROM.
<Lord_Nightmare>
i'd also clean the pcb surface since cadmium is incredibly nasty shit
<Lord_Nightmare>
not sure what to use to clean it with though
<Lord_Nightmare>
the fat angus you installed is a known-good part, right?
<Lord_Nightmare>
hmm. and the oscillator crystal that someone swiped was right next to the angus... check the very edge of the angus socket to see if someone didn't nick a trace when their soldering iron slipped
<ej5>
yeah all good things to check
<Lord_Nightmare>
since they did such a 'fantastic' job of desoldering the old crystal, it looked like they ended up physically tearing it off, leaving its 4 legs still soldered in the holes!
<ej5>
oddly enough it can transmit data out the serial port (which is Paula, on the custom chip bus)
<ej5>
nah it's mostly solder blobs
<ej5>
i'll have to ask jeri if it was her handiwork (i got the board from her junk pile a while back)
<ej5>
i might also do the chip swap thing with a known good board to make sure they all work, individually
<Lord_Nightmare>
I'm looking at your old tweets about making those 64pin SIMMS for the GVP processor card... are those the same as the 64pin simms apple used on the mac IIfx?
<Lord_Nightmare>
i'm guessing no, since i recall the IIfx simms use a weird type of memory with registers/latches for the input and output bus
<Lord_Nightmare>
which are a chip type only available as pulls or rare NOS parts, and you're better off using an FPGA and some sdram to emulate the old memory bus type
<ej5>
different pinout
<ej5>
anyway i am off to bed, ttyl. i have some ideas for things to check tomorrow.
<Lord_Nightmare>
cool, ttyl
<andlabs>
I still wonder what's in the amiga 1000 that I have that I don't already know about
<andlabs>
I vaguely recall the listing saying something about increased RAM but that's it
<andlabs>
which leads me to my next question: I wonder if I can write an ADF image using a MSX
<andlabs>
though I already have my scheduled planned for tomorrow so
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<ZrX-oMs>
ADF with MSX???
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<andlabs>
no, writing an ADF image onto a 720k floppy disk using an MSX with a 720k floppy drive
<andlabs>
but on second thought I'll hold off for now
<andlabs>
(it will probably require directly talking to the FDC anyway)
<andlabs>
while doing this will let me get up and running with AmigaOS 3.0 faster since my official disks are corrupted, the way I have things stored and the lack of space I have now will mean that setting up and putting away my a1000 will be a massive hassle each time
<andlabs>
(I have a Panasonic FS-A1F with a working drive)