Search found 374 matches

by Jorge Nuno
Mon May 29, 2017 12:52 am
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

I'm sending this out during this week to a PCB fab, just need to do second review. RevisedUMDK_S.jpg 4K Res: http://img.ctrlv.in/img/17/05/29/592b6f95c932d.png Board is 2-Layer and all components are on top side. Passives are 0402 which could be tricky for hand soldering (I'm able to do it fine) SD ...
by Jorge Nuno
Mon May 01, 2017 10:41 pm
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

From my experience with the spartan6, you can use any fpga pin for a clock OUTPUT pin, DCM'ed or not does not matter. To do it properly an ODDR-FlipFlop needs to be instatiated (or somehow inferred) where d0/d1 is 0/1, Clock1 is the positive clock, and Clock2 the negation of it (or the DCM 180º outp...
by Jorge Nuno
Mon May 01, 2017 8:30 pm
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

I'm pretty sure this bus abnormality is not there in normal cases. I've done a bunch of different types of MD cartridges already and never seen something like this on any HW revision. I know the FPGA pins are all swappable but I wanted to keep the same pinout for maintanability reasons. The only dif...
by Jorge Nuno
Mon May 01, 2017 1:53 pm
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

Sorry for hijack but I decided to take a more "drastic" approach:

Image

4K: http://img.ctrlv.in/img/17/05/01/59073d5edcab7.png

Still need a few weeks or something to finish it though
by Jorge Nuno
Mon Apr 24, 2017 10:41 am
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

I just realized what it could be a conceptual issue. UMDK uses no CE_0. So how does it know if the TMSS binary is executing or not? If it does not and forces the bus, irrelevant of the state of A14100 then it might be the issue that 2 devices are forcing data on the bus. CE_0 is not active when the ...
by Jorge Nuno
Sun Apr 16, 2017 2:11 pm
Forum: Demos
Topic: OVERDRIVE II
Replies: 29
Views: 4953

Re: OVERDRIVE II

SegaTim wrote:What emulator supports it?
Many reject it from the size being too big. The rest have timing and display issues.

So, no emu supports it as of right now.
by Jorge Nuno
Tue Apr 11, 2017 8:27 am
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

HardWareMan VDP pin 118 :wink:
by Jorge Nuno
Sun Apr 09, 2017 5:21 pm
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

It looks like CAS0 (You people like to call it OE for some freaking reason) has either: 1: Disturbance from nearby signals toggling /ground bounce. 2: Resonance due to signal driver, trace lengths + parasitic elements both on PCB and component pad. 3: Buffer itself on the "addon" board is driving th...
by Jorge Nuno
Sat Apr 08, 2017 7:21 pm
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

This looks like metastability to me, aka not double-registering inputs. I've never experienced this kind of problem with my carts (DMA oh yes).
Also prophet36, any special reason for not using CE_0?
by Jorge Nuno
Fri Apr 07, 2017 10:47 pm
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

I meant the probe itself, it should have a model on a label/or engraved somewhere probably near the BNC plug. The scope is able to see 100MHz from the specs, but if the probe is killing it then there are no miracles. If the probe has a 1x / 10x selection switch, then use the 10x attenuation setting ...
by Jorge Nuno
Fri Apr 07, 2017 8:01 pm
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

I measured it on a european model 1 with TMSS (VA6) on the cart slot pin. It could be that different revisions have different signal characteristics. I don't know if you noticed but there's RLC filter on the EDClk line probably to reduce signal reflections and/or EMI. This filter could have been sub...
by Jorge Nuno
Wed Apr 05, 2017 8:04 pm
Forum: UMDK
Topic: MD hangs after playing any PCM file
Replies: 69
Views: 9395

Re: MD hangs after playing any PCM file

What I can see here is that you're either loading the signal significantly or your equipment doesn't have enough bandwidth (or both). As this clock signal is used by the VDP for video timings and DMA bus operations, when you probe it then the signal will have a slower edge delaying the DMA operation...
by Jorge Nuno
Wed Apr 05, 2017 3:42 am
Forum: Hardware
Topic: What would be a DIY dev kit ?
Replies: 13
Views: 1755

Re: What would be a DIY dev kit ?

As a HW guy myself too, I totally agree with HardWareMan. Old debugging hardware is almost useless and it's good in a museum. A proper modern cart does it better, faster, more reliably, and doesn't require fiddling with oldass computer hardware/software that has no use othrwise. Acquiring the whole ...
by Jorge Nuno
Sun Apr 05, 2015 2:24 am
Forum: Blabla
Topic: Revision 2015
Replies: 3
Views: 1619

Oh hey! It's me 8)
by Jorge Nuno
Fri Mar 20, 2015 6:59 pm
Forum: Hardware
Topic: Model 1 MD PCB hacks topic
Replies: 17
Views: 6291

I think I know the deal about the VA6.8: The VA7 ASIC (same as used in the MD2-VA0 for the most part) - the 315-5487 has some issues with PAL mode, and looking at the date stamps on the ICs between a VA7 and a VA6.8, the first has earlier dates than the latter. so maybe it was an EU-only version, un...