Search found 89 matches

by db-electronics
Mon Apr 24, 2017 2:44 pm
Forum: Megadrive/Genesis
Topic: Info on mapper used for UMK3 hack
Replies: 1
Views: 538

Info on mapper used for UMK3 hack

I've been looking for info on this online, from what I've been able to find it didn't use the SSF2 mapper but I can't seem to find specific info on how it mapped its data in the cartridge space. Anyone have any info on this?
by db-electronics
Thu Apr 20, 2017 6:19 pm
Forum: Announcement
Topic: Future of SpritesMind
Replies: 38
Views: 5166

Re: Future of SpritesMind

I for one support our new BigEvilCorporation overlord... ;)
by db-electronics
Tue Apr 18, 2017 8:27 pm
Forum: Megadrive/Genesis
Topic: Paprium and it's sound engine
Replies: 16
Views: 2994

Re: Paprium and it's sound engine

TmEE co.(TM) wrote:MD2 VA0 and 1 have no 75ohm loading, VA3 and VA4 do
Really?! I'm going to have to test this tonight - I knew I bought 10 megadrives for a reason!

I also always reference the VA0 and VA1 schematics, I've never seen a Model 2 schematic with 75 ohm input loading.
by db-electronics
Tue Apr 18, 2017 8:12 pm
Forum: Megadrive/Genesis
Topic: 68000 programming optimization tips? (for speed)
Replies: 27
Views: 3017

Re: 68000 programming optimization tips? (for speed)

oops! Thanks for pointing out my mistake!

Edit:

Well wait, here's the table:
http://oldwww.nvg.ntnu.no/amiga/MC680x0 ... mmove.HTML

Oh I see,

Code: Select all

move.l D0, -(A0)
is optimized, but

Code: Select all

move.l -(A0), D0 
is not.
by db-electronics
Tue Apr 18, 2017 7:56 pm
Forum: Megadrive/Genesis
Topic: Paprium and it's sound engine
Replies: 16
Views: 2994

Re: Paprium and it's sound engine

You can most definitely feed audio into the Megadrive via the SL and SR pins on the cartridge port - this is how the FM Power Base Converter works. One thing to note however is that the input impedance is dractically different on Model 1 (75 ohms) and Model 2 ( > 10Kohms) which invariably leads to a...
by db-electronics
Tue Apr 18, 2017 7:42 pm
Forum: Megadrive/Genesis
Topic: 68000 programming optimization tips? (for speed)
Replies: 27
Views: 3017

Re: 68000 programming optimization tips? (for speed)

There are "mundane" optimizations you can figure out by staring at the instruction set long enough, most of which are covered in BigEvilCorporations links shared above. But as one example, you should try post-incrementing with the address registers instead of pre-decrementing since post-inc is faste...
by db-electronics
Mon Apr 10, 2017 7:02 pm
Forum: Announcement
Topic: Future of SpritesMind
Replies: 38
Views: 5166

Re: Future of SpritesMind

You need moderators. At least two who've contributed or been here the longest. Positive members with good judgement. People you can talk to about any problems regarding the site. Bounce ideas off of. People to work directly in the forums interacting with members, enforcing the rules and getting the...
by db-electronics
Fri Mar 31, 2017 3:27 pm
Forum: UMDK
Topic: UMDK Manufacturing - word of advice
Replies: 10
Views: 1471

Re: UMDK Manufacturing - word of advice

All I wanted was for everyone to know when to use HASL vs. when to use hard-gold plating because these things are important for PCB edge connections. I'm really sorry it caused such a big fuss...
by db-electronics
Mon Mar 20, 2017 12:19 pm
Forum: UMDK
Topic: UMDK Manufacturing - word of advice
Replies: 10
Views: 1471

Re: UMDK Manufacturing - word of advice

Sure thing! Here's picture I took of two boards of mine: one ENIG and one HASL, both went through about 300 mating cycles.

Identifying which you have is very easy; ENIG is gold coloured while HASL is grey.

https://twitter.com/db_electronics/stat ... 2031174657
by db-electronics
Sat Mar 18, 2017 5:22 pm
Forum: UMDK
Topic: UMDK Manufacturing - word of advice
Replies: 10
Views: 1471

UMDK Manufacturing - word of advice

[KanedaFR : Based on some previous issues with Minty, db's contacted me to clairy explain his goal, following a chat he had with a lucky UMDK's owner. I think it is in sync with this forum's goal : share info and help each other. Else I would have already deleted this post. Please take it for what ...
by db-electronics
Wed Mar 30, 2016 12:22 am
Forum: Tools
Topic: Retro Graphics Toolkit
Replies: 114
Views: 25682

Re: Retro Graphics Toolkit

FYI I just built and installed RetroGraphicsToolkit on Ubuntu 14.04 and it needed all of this before building correctly: sudo apt-get install libreadline6-dev sudo apt-get install libfltk1.3-dev sudo apt-get install zlib1g-dev sudo apt-get install libpng-dev sudo apt-get install libjpeg-dev sudo apt...
by db-electronics
Fri Feb 19, 2016 7:22 pm
Forum: Cartridge
Topic: SRAM write protect
Replies: 5
Views: 1866

Re: SRAM write protect

My Super Street Fighter II cartridge had a modification compared to db-elec's, there's a 0.1uF ceramic capacitor soldered between pins 8 (/VRES) and 11 (ground) of the 315-5779 custom. The PCB layout is identical, the capacitor is directly soldered to the pins of the chip as some kind of post-assem...
by db-electronics
Mon Feb 08, 2016 1:39 pm
Forum: Hardware
Topic: Hmmmm.......?
Replies: 25
Views: 6721

Re: Hmmmm.......?

Very good work! Auto-routers are for wimps! (And blokes who don't care for signal integrity)...
by db-electronics
Mon Feb 01, 2016 4:24 pm
Forum: Hardware
Topic: [WIP] Not a debug cart project!
Replies: 46
Views: 7861

Re: [WIP] Not a debug cart project!

MegaWifi!!!
by db-electronics
Mon Feb 01, 2016 4:19 pm
Forum: Hardware
Topic: Hmmmm.......?
Replies: 25
Views: 6721

Re: Hmmmm.......?

Very happy to see actual level converters on there...