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There is only one clock domain at M68K bus: VCLK. I must correct myself with CAS0/CAS2 timing: CAS0 before CAS2. Sorry. Notice: CAS0 assert with AS simultaneously. But it must be OK while M68K is master: AS assert when address is steady. But your true: while DMA there is no AS. Ah, that makes more ...

You know what would be cool? A 32X in a cart. Surely that's possible with today's tech! If you threw out the instruction trace FIFO, you might be able to implement the 32X logic in a UMDK cart. According to Wikipedia the 32X was based on a couple of Hitachi SH2s. There's an open-source implementati...

Is !DTACK stuck high or such ? It's not my console that's doing it so I can't check, but I asked Montserrat to look at various 68000 signals like /DTACK, /BG, /BGACK, /BR, /BERR and CLK. That said, I'm pretty sure the 68000 ignores the state of /DTACK unless /OE, /LDSW or /UDSW are asserted, and yo...

unfortunately i got fired day 1 Shit, really sorry to hear that. Let me know if there's anything I can do (e.g proofread an English CV/Resume or whatever). Is there any other way to make that check? Actually, you could use your multimeter. Be sure to put it in voltage mode, then get the PAL-i machi...

We've hit a weird problem with one of Montserrat's consoles over on the UMDK forum: http://gendev.spritesmind.net/forum/viewtopic.php?f=20&t=2239&start=195#p28406 This is a EURO PAL-i 1601-05 VA6 with a switchless mod by matt at dforce3000, failing to start Sonic 1. The SGDK-based UMDK menu program ...

Hi Montserrat ! I looked at your PAL-I trace, and it's a complete mystery. The 68000 just seems to stop executing in the middle of an innocuous bit of code (ooh, déjà vu...): http://i.imgur.com/LnH2XXP.png For comparison, here's what it should look like (this is from your PAL-G trace, actually): htt...

prophet36: Since UMDK is a slave on M68K bus, I think you should allow only one access cycle from AS assertion. Any other "request" must be discarded till next AS assertion. I'm fairly sure that won't work, since VDP DMA doesn't assert /AS, only /C_OE, which is the signal with the glitch above. Bes...

Sure, here they are: Great, thanks. Here's the problem with the PAL-G trace. As predicted, a spurious premature assert of /OE: http://i.imgur.com/nkcfDoX.png I'll need to add some protection logic in the FPGA to prevent this being interpreted as the start of a read operation that should not actuall...

OK Montserrat , can you try this on your PAL-I and PAL-G machines? I need two logic analyzer traces, one from a crash (address error, illegal instruction or line 1111 emulator, etc) during the "Sega!" sample on the PAL-G machine, and another from a blank screen startup-fail on the PAL-I machine (cha...

Grind wrote:The byte that failed is 77590, which in hex is 12F16 and half that 978B so I checked here

Oh, wait. Why halve it? If the byte that fails is 77590, you need to look at the write to 0x412F16 (0x400000 + 77590) in the trace.

The byte that failed is 77590, which in hex is 12F16 and half that 978B so I checked here 15027612 C WB 409788 ABF0 15027750 C WB 40978A EE56 15027900 C WB 40978C EEC9 15028038 C WB 40978E 5B84 Fair enough, but what does random.bin look like near there? Try "od -tx1 -Ax -v random.bin". The leftmost...

I seem to have a problem with the onboard flash tests I did not have last month when I first got the cart. $ cmp readback.bin random.bin readback.bin random.bin differ: byte 77590, line 299 That looks like the flash readback test , which didn't exist last month. If the cmp command returns an error ...

I've been working on providing an alternative to the trace log for those times when you want to see in detail what's going on at the signal level. The result is a 48MHz logic analyzer, which UMDK provides "for free". Unfortunately there's not enough USB bandwidth to sample all 44 bus signals continu...

the unlabeled resistor at R11 in the BOM can be anything, right? R7, R8, C30, R11 & R12 on the LX9 board are all unused by the UMDKv2 design and should be left unpopulated. Similarly for Q2 on the bridge-board. I think everything else on the BOM is described by the LX9 and bridge NOTES.txt files. A...

I've aplied a switchless mod, i did the same way as for the pal-1 asian version, id added a PDF with the details next to the new traces: About the traces, i've done 5 new sonic1 traces in a row whitout shutting down the console and got something interesting A and B did similar, C begin giving me "d...