Search found 959 matches

by TmEE
Tue Feb 28, 2023 6:37 pm
Forum: General Stuff
Topic: The Sega Master System thread
Replies: 77
Views: 54627

Re: The Sega Master System thread

There are several board versions and only the earliest one has MD1/SMS style AC brick connection from what I see. What the rest is like I cannot comment on too much, I have only ever held euro stuff in my hands. Sega Retro is full of things that are not quite right. TMSS does basic hardware init and...
by TmEE
Mon Feb 27, 2023 6:26 pm
Forum: General Stuff
Topic: The Sega Master System thread
Replies: 77
Views: 54627

Re: The Sega Master System thread

GG VA0 and I think VA1 use MD1/SMS style connector, later models (up to VA4) use MD2 style connector. In europe I mostly see VA0, without TMSS screen but later models do exist. Plugging in a brick can cause a crash as it will be physically switching the DC-DC converter input from battery to external...
by TmEE
Thu Feb 23, 2023 3:50 pm
Forum: SNESdev
Topic: Help with custom SNES case
Replies: 9
Views: 1540

Re: Help with custom SNES case

Multimeter is unable to show the small wiggles that happen when signals change state, capacitor is able to help provide the instantaneous current needs. Oscilloscope is able to show a whole new world lol
by TmEE
Thu Feb 23, 2023 1:15 pm
Forum: SNESdev
Topic: Help with custom SNES case
Replies: 9
Views: 1540

Re: Help with custom SNES case

20" is almost 51cm, that is a very long cable. You absolutely need shielding then and even then it may not work in the end. This amount of cable will round off signal edges quite a lot and there will definitely be power issues assuming it is standard ribbon cable seen in old PCs, those skimpy w...
by TmEE
Thu Feb 23, 2023 10:08 am
Forum: SNESdev
Topic: Help with custom SNES case
Replies: 9
Views: 1540

Re: Help with custom SNES case

This is definitely a signal integrity issue, good enough oscilloscope will be able to show it. How long is that extender ? You likely need to actually shield your cables, i.e grounded aluminium or copper foil around the ribbon cable. You may need to add fat GND and VCC wires and also some bulk capac...
by TmEE
Wed Feb 22, 2023 4:45 am
Forum: General Stuff
Topic: The Sega Master System thread
Replies: 77
Views: 54627

Re: The Sega Master System thread

Atari Lynx with its different color backlit screen has exactly the same problem low battery life problem. Majority of the power use comes from driving that 1W backlight bulb and the associated inverter, rest of the unit takes only a small amount of the total and there isn't a huge need to try to opt...
by TmEE
Thu Feb 16, 2023 1:39 am
Forum: General Stuff
Topic: The Sega Master System thread
Replies: 77
Views: 54627

Re: The Sega Master System thread

Hmm according to my notes the MD simply reverts the values read from the pins to satisfy the usual system detection routine, but this behavior is not exactly the same as a Japanese MS and could possibly be used to detect a Mega Drive. And it seems the MD controllers would not work on a Mark III aft...
by TmEE
Tue Feb 14, 2023 8:18 am
Forum: NES Music
Topic: VRC7 Patch Switching
Replies: 2
Views: 1413

Re: VRC7 Patch Switching

It makes sense that it works this way, since ADSR parameters only take effect on new note-ons on all other FM chips, while rest of the parameters update immediately. The ROM based parts shouldn't be any different on this behaviour but I have not actually explicitly tried this myself on OPLL, only on...
by TmEE
Mon Feb 13, 2023 5:05 am
Forum: General Stuff
Topic: Is the composite video of an NTSC Genesis really this bad?
Replies: 24
Views: 4080

Re: Is the composite video of an NTSC Genesis really this bad?

In theory yes, but there will be moving dot-crawl/jailbars interference pattern as the clock isn't locked to video signal coming out the VDP. What freq is the master clock oscillator in the machine ? It should be 53.203424MHz for true PAL machines or 53.693175MHz for NTSC ones, in which case you cou...
by TmEE
Sun Feb 12, 2023 8:18 pm
Forum: SNESdev
Topic: Adlib Emulator on SPC?
Replies: 17
Views: 1775

Re: Adlib Emulator on SPC?

You can definitely use it to ease up the pain a little.
by TmEE
Sun Feb 12, 2023 7:54 pm
Forum: General Stuff
Topic: Is the composite video of an NTSC Genesis really this bad?
Replies: 24
Views: 4080

Re: Is the composite video of an NTSC Genesis really this bad?

Those rainbows are present in many NTSC models, some worse than others. The mechanism of why is explained and it stems from very simple(aka cheap) filters on CXA1145 external circuitry which converts the RGB output of VDP into CVBS for AV out and RF modulator. I remember some later models use CXA146...
by TmEE
Sun Feb 12, 2023 7:48 pm
Forum: General Stuff
Topic: The Sega Master System thread
Replies: 77
Views: 54627

Re: The Sega Master System thread

Yeah, MD in JP mode disables some aspect sof the controller ports so that games will detect the region right. I had actually forgotten that is how one can differentiate JP SMS/Mk3 from an US/EU one, I even have the code written in my SMS library ages ago lol
by TmEE
Sun Feb 12, 2023 1:33 am
Forum: General Stuff
Topic: The Sega Master System thread
Replies: 77
Views: 54627

Re: The Sega Master System thread

SMS (only US and EU models) has two pins (TH and TR) that can change direction so Saturn pads with the right kind of adaptor are not out of question. JP machines only have one pin that is hardwired as output from what I remember so it won't be possible to use Saturn pads on them. MD has input/output...
by TmEE
Sun Feb 12, 2023 1:17 am
Forum: SNESdev
Topic: Adlib Emulator on SPC?
Replies: 17
Views: 1775

Re: Adlib Emulator on SPC?

As far as trying to emulate OPL or other family of some Yamaha chip, that will not even approximate, it won't sound anything near what the sound should be except maybe for some sounds that have missing attack transient etc. but as just general "FM" style sound generation with its own rules...
by TmEE
Sat Feb 11, 2023 1:44 am
Forum: General Stuff
Topic: SNES button mapping
Replies: 27
Views: 5108

Re: SNES button mapping

There could be "hold down this button for that conf when powering" or such for selecting one's preferred conf without having to go into a menu first.