Search found 19 matches

by Lord Nightmare
Sun Aug 04, 2019 11:35 am
Forum: Sound
Topic: Looking for latest GEMS
Replies: 29
Views: 51466

Re: Looking for latest GEMS

WOW! Thank you so much for doing this! The pcb calls the two gals "PAL16L8" even if they used lattice gal parts... if you can figure out which pins are inputs and outputs (which can vary based on the fusemap) it should be possible to brute force a truth table out of those parts, even if they are pro...
by Lord Nightmare
Sun Aug 04, 2019 7:08 am
Forum: Sound
Topic: Looking for latest GEMS
Replies: 29
Views: 51466

Re: Looking for latest GEMS

Thanks so much! Did you ever end up doing high-res scans of the front and back ROM/RAM carts? I'm trying to figure out the memory map of the carts, and I can't read the 74xx chip labels on the pictures at http://www.tmeeco.eu/FileDen/GEMSstuff.jpg I know from the GEMS 2.8 program that at 0x19f8 it w...
by Lord Nightmare
Fri Aug 02, 2019 10:56 pm
Forum: Sound
Topic: Looking for latest GEMS
Replies: 29
Views: 51466

Re: Looking for latest GEMS

TmEE co.(TM), is there a chance you have the schematic for the parallel port to EXT adapter available somewhere? I'd like to breadboard one myself. I'm also curious what the memory map for the ROM/RAM carts is (and what the 4 dipswitches do). I'm trying to throw together a working GEMS setup... BTW,...
by Lord Nightmare
Thu Dec 31, 2009 5:51 am
Forum: Announcement
Topic: A New SMS/GG/Colecovision Ripped Music Format!
Replies: 1
Views: 13816

A New SMS/GG/Colecovision Ripped Music Format!

http://nesdev.parodius.com/bbs/viewtopic.php?t=5887 Kevtris writes: "Wellll, since no one had made one, I decided to. I came up with a new SMS/GG/CV ripped music format I called SGC. Unlike most of these things I got some rips to back it up. I ripped no less than 365 sets of music from various games...
by Lord Nightmare
Thu Jul 16, 2009 5:26 pm
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

What happened with this? Did the weird stuff get documented? Eke, did you manage to fix the core?

LN
by Lord Nightmare
Tue May 19, 2009 3:49 pm
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

BTW, could the differences on those graphs on the prior page, between the ym2612 and the sega asic version, be because the sega asic one has the 'off by one' error on the descending portion of the sine wave fixed?

LN
by Lord Nightmare
Fri May 01, 2009 2:09 pm
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

Ok, even if I don't understand the exact importance of them, those images look DAMN cool! Wouldn't they look identical between MD1 and MD2 if both were sampled at the same rate? Does the samplerate have a large effect on those images? Does anyone have a ym3438/opn2c to compare to the opn2 in the md1...
by Lord Nightmare
Sun Apr 12, 2009 1:38 am
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

YM2612/YM3438 are not the only chips which do time-multiplexing of the output channels rather than using a 'real' accumulator to mix them (the 3438 DOES use multiplexing, right?): The YM2413 OPLL and the Konami VRC7 (which is a reduced-ym2413-on-a-famicom-mapper-chip, almost certainly manufactured b...
by Lord Nightmare
Fri Nov 21, 2008 4:14 am
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

I did top-illumination using a 1940's binocular scope (my mom used it in medical school in the 1970s) by taking one eyepiece lens out and sticking a flashlight in the hole (being sure it didn't fall in and scratch something). It DOES work, but only so-so; you get a lot of light from the second eye d...
by Lord Nightmare
Mon Nov 10, 2008 7:32 pm
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

opl2 rom3: This decoding is based on http://yehar.com/adlib/ym3812_rom3_1.jpg Legend: 0 = dark/absent gate, 1 = light/present gate C = clear/correct for this address, C? = probably correct. X = a pullup or perhaps pulldown between every 2nd rom line, only present on bits which need it. This was usef...
by Lord Nightmare
Sun Nov 09, 2008 9:41 am
Forum: Tools
Topic: TFM Music Maker
Replies: 278
Views: 364440

Two questions: was the minor fix to fm.c (ym2203_emu.cpp in tfmmaker): ** 14-02-2006 Alone Coder: ** - fixed YM2203 stop volume (511 instead of MAX_ATT_INDEX) - verified on real chip ** - fixed YM2203 SSG-EG=#0a key off (inversion disabled) - verified on real chip ** - uncommented sine generator in ...
by Lord Nightmare
Thu Nov 06, 2008 1:47 am
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

I got the high-res opl2 pics from Olli (he goes by 'yehar' on ircnet), and unfortunately, not all the chip is imaged at high res. There is also at least one smaller rom on it (roughly 16x7 bits), which could be key-shift or other LUT tables which are not imaged at a high enough resolution yet to be ...
by Lord Nightmare
Thu Oct 23, 2008 4:43 am
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

ouch. whoever owned that megapc snapped capacitor c113 off of the MD isa card. SOMETHING is gonna work completely wrong until that is replaced. EDIT: nope, once again I'm wrong. C113 is NOT SUPPOSED to be populated. see a later megapc plus card here: http://aycu14.webshots.com/image/27693/2003058353...
by Lord Nightmare
Mon Oct 20, 2008 2:36 pm
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

I've updated the post above with the systems list with tmee's corrections, and to include late MD2 and MD3. Please add comments. Also, which MD2 has the z80 inside the giant asic? VA4? Thanks to tmee's correction, I know all the va1.x ssytems are really 'VA1' systems regardless of the second number,...
by Lord Nightmare
Sun Oct 19, 2008 12:48 am
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 865
Views: 2478364

In response to ym2612 versions, there appear to be 7 variants of the MD system *in terms of ym2612 and VDP*: MD1 VA0 thru VA6: use a real yamaha ym2612 and a real 315-5313 VDP (note that va0 and va4 (and likely the intervening models, but please correct me) have 3 asics, while at least va5 and va6 h...