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
<cr1901_modern>
the actual chip is in the center of the PCB
<superctr__>
sure
<superctr__>
but the EPROMs are from 1989 :P
<superctr__>
Considering that it's an EPROM cartridge, the datecodes don't really have to correspond to the date of the build
<cr1901_modern>
There are no datecodes for the build
<superctr__>
the cartridge is probably much older than the build in any case
<superctr__>
exactly
<cr1901_modern>
So I'm trying to get a lower bound
<superctr__>
well, we can definitely say it's after the Tokyo Toy Show build
<cr1901_modern>
Also, the EPROMs are soldered in. Why would they be soldered in in 1989 when the other chip wasn
<superctr__>
that's your lower bound
<cr1901_modern>
't made until 1990?
<superctr__>
now, although this probably isn't the case here, it is even possible that the build is _older_ than the cartridge manufacture date
<superctr__>
since they could just have stored it on a BBS and flashed it long after the actual build date
<ZrX-NoMs>
Direct cartridge programmer
<cr1901_modern>
is there a datecode for the cartridge? I didn't see it
<cr1901_modern>
>Direct cartridge programmer
<cr1901_modern>
Those are a thing?
<superctr__>
there is none that I can see either
<superctr__>
as for programming the whole cartridge, it would be possible if the pins used to set the eproms in programming mode are easily accessible through the edge connector or some other way (like a header, which I don't see)
<cr1901_modern>
Anyways, it's a cool prototype, just curious the time frame of how old it is. I think the Sonic 3 build is more interesting, but I'm biased :P
<superctr__>
usually you need to apply a high voltage (12.5V in the case of these NEC eproms) to one of the pins to program it
<superctr__>
also, a final thing. These kinds of prototype cartridges don't tend to be the kind of things to be JIT-manufactured, unlike consoles and "mass production" cartridges. So don't expect the datecodes to be anywhere close to the time the cartridge itself was assembled in any case. Now talking about the cartridge, not the game build
<superctr__>
I think the only way to determine the date of the game build is to compare it to known builds (we might not have ROMs but we do have newspaper articles, screenshots etc)
<cr1901_modern>
I expect my lower bound to be off by a bit. I would say late 90/early 91
<superctr__>
I think your estimate is pretty close to mine. I estimated about 2-3 months prior to the final build
<superctr__>
according to the HP article, the final build is dated at the latest May 1st 1991
<superctr__>
also I think that january/february matches up pretty well with the other "milestones" mentioned in the article
<superctr__>
"The media would receive their first preview cartridges sometime around February/early March for their late March, April, (and sometimes) May issues." and "Sonic made his first “official” debut at the Winter International Consumer Electronics Show of 1991 (WCES 1991), which ran from January 10th to the 13th at the Las Vegas Convention Center. "
<cr1901_modern>
ZrX-NoMs: Is that from your collection?
<Lord_Nightmare>
datecode is 1990
<Lord_Nightmare>
so the cart must be from after the datecode of that 74hc139
<Lord_Nightmare>
the eproms are re-used or NOS older parts
<cr1901_modern>
I read some comments on Twitch that suggest this was another Nick Arcade prototype. Yes, a Nick Arcade prototype for Sonic 1. But they could be confused.
<cr1901_modern>
I'll have to ask someone who might know more info about where the proto came from (other than it was someone's private collection and they generously donated)
<fseidel>
cr1901_modern: it seems the pilot of nick arcade did feature a Sonic 1 Beta
<cr1901_modern>
fseidel: Looks identical from the like 1% of level we can see :P
<cr1901_modern>
"RING" counter, ball as obstacle
<ZrX-NoMs>
cr1901_modern: I have dumped it.
<andlabs>
oh that's different from the one that was sold recently
<andlabs>
hm
<andlabs>
also huh goldstar made 74xx chips
<cr1901_modern>
ZrX-NoMs: Well, the action of dumping it implies a superset of your collection. :D
<ZrX-NoMs>
It's the only MD dump I've ever done. :)
<cr1901_modern>
ECANTAFFORD protos
<ZrX-NoMs>
ROM was identical to release version except one byte and checksum.
<cr1901_modern>
Was did the one byte change?
<ZrX-NoMs>
In the header with the (C)SEGA copyright, ROM name etc. the release version has a letter C where the review dump has F.
<cr1901_modern>
huh
<ZrX-NoMs>
Not in the (C) but in the textfield.
<cr1901_modern>
(F)SEGA would be a bit strange, yes
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<andlabs>
Foone: wait what's the problem with the dremel
<andlabs>
or is the problem an overreliance on the dremel?
<Foone>
andlabs: the problem was he misused it, originally. he dremeled off a screw because he didn't have the right screwdriver handy
<Foone>
and I'm just mocking that after having that catastrophe, he's right back at using his dremel again
<Foone>
personally if I did something with a tool that got me roundly mocked by half the internet, I'd think about not pulling that same tool out for a bit
<emeb>
When your only tool is a dremel...
<andlabs>
oh
<andlabs>
well then ok
<andlabs>
=P
<andlabs>
I missed the "dremel off a screw" bit, though I'm sure I saw that video
<andlabs>
I just don't remember which one
<andlabs>
honestly we need to start having 3D printers big enough to print entire computer cases
<andlabs>
:/
<Foone>
it's the same video where he tried to get a power supply working by bridging a fuse with a paperclip
<emeb>
That whole video was a disaster - there were more gaffes than just the screw.
<andlabs>
oh
<andlabs>
I forgot that
<andlabs>
I only remember the paperclip thing =P
<andlabs>
at least his papercilp thing worked
<andlabs>
my attempt to use paperclips on the commodore 128 failed to do anything at all
<andlabs>
also that's not his fault for the shorted tantalum
<andlabs>
also
<andlabs>
Pietro Gagliardi, [01.01.21 12:02] I was rewatching lgr's xt 286 video earlier
<andlabs>
Pietro Gagliardi, [01.01.21 12:02] and I always skip to the part where he dremels at the rusted screws
<andlabs>
Pietro Gagliardi, [01.01.21 12:02] when I first saw that I thought he was using a welding iron and that made me laugh hysterically but no watching it again it's a dremel
<andlabs>
wait I'm watching the video again; i don't see a dremel here
<Foone>
is it a welding iron now?
<Foone>
it'd be amusing as a weird social experiment: upload two versions of a video, which are mostly identical but vary in some subtle differences. set up a script to automatically toggle which one is public and which one is unlisted
* whitequark
stares at Foone
<Foone>
sorry. I'll get back to using an angle grinder on this minicomputer
<andlabs>
Connectors Molex 39-01-2200 compatible, two 3.5” drive power connectors (PATA and SATA) and one P4-12V 4 connector (mini-fit JR 4p). Header and mating connector for the removable cable harness can be found at: http://www.jst-mfg.com/product/pdf/eEH.pdf
<andlabs>
again I have no idea which parts to get
<fseidel>
that second PDF gives me a 404
<fseidel>
what exactly are you having issues finding, the power input connector for the AC->DC board?
<andlabs>
no
<andlabs>
I'm looking for the proper crimp connectors
<andlabs>
I know I can solder the wires directly and that's what we'll probably do but
<andlabs>
oh I can just use the one that came with the picoPSU and combine wires
<andlabs>
while we do that, what the fuck is up with prices on cga monitors
<andlabs>
$150 seems to be the LOWEST
<andlabs>
lots of people selling those weird GBS thingies that have noise and snow problems
<andlabs>
lots of extremely expensive LCDs that are listed as CGA when they're clearly for arcade machines
<andlabs>
why is there nothing like OSSC for CGA
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<andlabs>
I'll finish this later when I get the right crimp connectors
<andlabs>
so yeah
<andlabs>
what do I need for crimping or screw-connecting the wires to that table in the image I linked, the mating housing or the terminal?
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<Foone>
is the MCE2VGA not OSSC for VGA?
<andlabs>
oh!
<andlabs>
I forgot about that and it didn't show up for some reason
<andlabs>
huh
<andlabs>
ok, thanks!
<andlabs>
is the serdashop one the best?
<andlabs>
I know that's the one that gives all the samples to youtubers