Search found 1665 matches

by kyuusaku
Mon Mar 25, 2013 5:02 pm
Forum: NES Hardware and Flash Equipment
Topic: Use of parallel ports in NES/PC interfaces
Replies: 66
Views: 9507

Re: Use of parallel ports in NES/PC interfaces

It's not hard to get a PCI-E parallel port for a modern computer, it is however difficult to rewrite legacy software to use it.
by kyuusaku
Mon Mar 25, 2013 4:38 pm
Forum: SNESdev
Topic: YPbPr ouput mod for SNES consoles
Replies: 187
Views: 100175

Re: YPbPr ouput mod for SNES consoles

-The transistor amp above doesn't make any sense, it's just a weird buffer and serves no purpose here since it doesn't even transform the output impedance. -Right, putting two capacitors in series is the same as putting two resistors in parallel, you don't want that. For the input of the NJM amp jus...
by kyuusaku
Sat Jan 12, 2013 10:50 pm
Forum: NES Hardware and Flash Equipment
Topic: RGB output from composite PPU
Replies: 143
Views: 79875

Re: RGB output from composite PPU

We know it isn't a comparator. Short of some new exploitable HW discovery the key must be the priority multiplexer's propagation. The pixel's stabilization should be visible through the transparent latch, which can then be used to differentiate between background and sprite. Even if the multiplexer ...
by kyuusaku
Mon Dec 03, 2012 10:29 pm
Forum: NES Hardware and Flash Equipment
Topic: RGB output from composite PPU
Replies: 143
Views: 79875

Re: RGB output from composite PPU

It'd be far too obnoxious to recover the level with a 4-bit ADC since you'd need equipment and skills to develop a preprocessing circuit for level shifting and biasing. Instead you could stick a very typical 8-bit ADC between VDD & VSS and maybe have enough resolution, or definitely have enough with...
by kyuusaku
Mon Dec 03, 2012 8:08 pm
Forum: NES Hardware and Flash Equipment
Topic: RGB output from composite PPU
Replies: 143
Views: 79875

Re: RGB output from composite PPU

3 x 12 x subcarrier is probably quoted for asynchronous sampling, since 3x Fs can easily recover Fs unlike 2x Fs.

6x is OK if you're synchronized, and have two sample & hold circuits or two ADC, or an ADC with a built in PLL (video ADC often double 27 MHz to 54).
by kyuusaku
Mon Dec 03, 2012 7:47 pm
Forum: NES Hardware and Flash Equipment
Topic: RGB output from composite PPU
Replies: 143
Views: 79875

Re: RGB output from composite PPU

While the DE2 has the TV decoder, it doesn't appear he is using it... And if he were, it can't be used as a GP ADC since it appears wired solely for composite/directly spits out YUV-decoded pixels at some 13.5 MHz derivative of course. I believe the pin headers are strictly GPIO too.
by kyuusaku
Mon Dec 03, 2012 7:29 pm
Forum: SNESdev
Topic: YPbPr ouput mod for SNES consoles
Replies: 187
Views: 100175

Re: YPbPr ouput mod for SNES consoles

For the best video quality you'd need 2x video amplifiers, on Pb and Pr. TI makes pretty good video amplifiers. Basically connect the outputs to the amplifier's inputs. How to connect them depends on the amplifier. The output of the amplifier always connects to the multi-out through a 75 ohm resisto...
by kyuusaku
Mon Dec 03, 2012 6:39 pm
Forum: NES Hardware and Flash Equipment
Topic: RGB output from composite PPU
Replies: 143
Views: 79875

Re: RGB output from composite PPU

The only important question is "what's being used for an ADC"? Doesn't seem like anything is... So is it really a partial-PPU emulator that snoops bus activity?
by kyuusaku
Sat Nov 03, 2012 8:19 am
Forum: NESemdev
Topic: audio buffering and timing discrepancies
Replies: 34
Views: 9593

Re: audio buffering and timing discrepancies

"Underclock" the rest of the system to suit your sample rate.

Say 112 pixels / (1/48000) = 5376000 Hz = 0.12% error and everything will be in sync.
by kyuusaku
Thu Nov 01, 2012 10:41 pm
Forum: NES Hardware and Flash Equipment
Topic: Visual 2C02
Replies: 62
Views: 15735

Re: Visual 2C02

Here's an updated data set. It's in the most efficient format I can think of. [node name, pulled up, [[driver's gate node, driver's opposite node]]] Just eval() and dump lines into pull-up and driver dictionaries. Each of the drivers are implied transistors. Since the redundancy in the previous data...
by kyuusaku
Thu Nov 01, 2012 12:20 am
Forum: NES Hardware and Flash Equipment
Topic: Visual 2C02
Replies: 62
Views: 15735

Re: Visual 2C02

Anyone have any ideas on how to group transistors for comprehensible textual output? I've refined the node (guess I can call it "node", eww) organization so I can walk through the schematic and fairly easily transcribe it to paper, since my netbook doesn't really have the screen space, but that gets...
by kyuusaku
Wed Oct 31, 2012 5:03 pm
Forum: NES Hardware and Flash Equipment
Topic: Visual 2C02
Replies: 62
Views: 15735

Re: Visual 2C02

This might help: http://imageshack.us/scaled/thumb/707/69200610large.jpg Edits: Kind of funny that OAM and palette RAM make up 60% of the transistors. I've auto-captured the NOT and NOR gates, 1151 of them. Useful? I'll attach them anyway... The first element is the output net/node, the rest are inp...
by kyuusaku
Wed Oct 31, 2012 4:30 pm
Forum: NES Hardware and Flash Equipment
Topic: Visual 2C02
Replies: 62
Views: 15735

Re: Visual 2C02

org: I think you have the OAM row/word line's inverted, the rightmost line is high when all row bits are high, so shouldn't it be 31?
by kyuusaku
Tue Oct 30, 2012 11:10 pm
Forum: NES Hardware and Flash Equipment
Topic: Visual 2C02
Replies: 62
Views: 15735

Re: Visual 2C02

I rearranged the data into a better format for further processing:

[net name string, has pull-up boolean, attached gates list, attached sources list, attached drains list]

Edit: use updated format on page 3