Random STuff

[exxos]

PP's driver ?

[exxos]

ahhhh

So it is the interface I was working on with PP some years ago then..

cf2015p.jpg (99.45 KiB) Viewed 5255 times

At that time I was still researching the bad DMA myth so the project got stalled for a while because it had random bit errors. It all took time to resolve.. But of course by which time PP "left" here and I deleted any mention of this project because he accused me of being a thief of his work and doing it for commercial gain.

[DoG]

Yup. Probably that.

[DoG]

I got another Mega... A Mega ST4. I think I have enough of them now...

But back to the memory upgrade of the Mega ST2. I desoldered the "beta" PCB on U40-U43 and changed it for a newer one. I also desoldered all the other chips and capacitor and solder in new boards. Well it didn't work of course. Out with the diagnostic cartridge and some null modem cable.

All the chips

Bit U46,U47, CAS,GND tied together, changed chip on U48,U49,U50,U51.jpg (587.1 KiB) Viewed 4939 times

Tied together

Bit U46,U47, CAS,GND tied together.jpg (400.91 KiB) Viewed 4939 times

Some strange results. I went over all the connections with a multimeter in continuity test. Found that bit on U46, U47 and CAS was connected to ground. Some sort of connections between those. So used solder wick to drag the solder out of the J-legs on the SMD memory chips.

Changed chip

Changed chip on U48,U49,U50,U51.jpg (281.78 KiB) Viewed 4939 times

Still didn't work. Four bits are held high and since the chips I'm using has four bit each, one of them seems broken. The memory test leads me to the U48-U51 PCB. Desoldered the chip with my heat gun and soldered in a new one. That did the final trick. All 4Mb accounted for now.

[DoG]

I assembled/soldered up a mt32-pi-midi-hat for the mt32-pi project a while ago. It's a software Roland MT-32 MIDI synthesizer module based on Raspberry Pi/Munt (RPi 3 A+ used here). I made some custom top and bottom black PCB for it. The black screws is to press and reach the buttons below. Fast and quick solution.

MIDI PiHat2.jpg (244.43 KiB) Viewed 4933 times

MIDI PiHat1.jpg (200.57 KiB) Viewed 4933 times

[DoG]

Bought an ACSI2SD kit from eltradec. Based on SCSI2SD and can thus be connected to win/mac/linux and use the scsi2sd-util to configure it. The firmware on it makes it however restricted to 1Gb "diskdrives". Similar restriction exist with other devices, like the internal SCSI adapter on the MegaSTe. But you can make four "diskdrives" with the utility program.

ACSI2SD Unsolder.jpg (414.58 KiB) Viewed 4635 times

ACSI2SD Back.jpg (204.42 KiB) Viewed 4635 times

[DoG]

Well, is it going to be solder on or isn't it? I don't know. I can see U11 and the before and after looks the same to me. Oh, BTW, JLCPCB does SMT on all the colors now, on 6 layer boards too.

U11.jpg (221.14 KiB) Viewed 4146 times

[Steve]

Hey @DoG I got the same asci2sd kit as you and have built it up to the point where I can test scsi2sd-util and upload the default configuration, but it isn't being detected properly. Could you do me a favor and take a photo of the other side of your device so I can check my soldering?

Their website is absolutely ridiculous... look at this fluffy bunny:

1. Solder U1 (PQFP100), pay attention to the orientation, compare with photos.

A_Proc_10_1_kl.jpg (44.75 KiB) Viewed 3943 times

No joke! compare with THIS BLURRY FLUFFY RABBIT PICTURE.....

Not even kidding (for anyone who hasn't seen it) look at this stuff: link

[DoG]

Hey @DoG I got the same asci2sd kit as you and have built it up to the point where I can test scsi2sd-util and upload the default configuration, but it isn't being detected properly. Could you do me a favor and take a photo of the other side of your device so I can check my soldering?...

Yeah, I know what you mean about their pics. Super strange. BTW, I soldered in my LED and resistor, that goes along with it, on the wrong place. It should be on the side on the pic below. Choose 'Activity' or 'Power'. The build BOM is slightly wrong on the the placement for the LED and the resistor that goes along with it if I remember correctly. But it says in the text somewhere I think. I have bought some more LEDs and resistors to put in the other places as well. Here is the photos I have at the moment:

ACSI2SD1.jpg (127.32 KiB) Viewed 3930 times

ACSI2SD2.jpg (238.55 KiB) Viewed 3930 times

[DoG]

I did my own board for masteries ACSI2STM v2. Since there was some changes made in the code recently I updated the board for that. So I transferred some parts from the 'blue pill' board. Added the footprint for a micro SD card. 2 different footprints for 3.3V regulators. Also 2 different reset switch footprint since I had some different variants of 'blue pills'. Also RTC clock stuff could be transferred but I don't know if that is in use for anything but it exist on the original 'blue pill' board so I added it.

I played around with it for the first time today but I haven't test the speed yet. Should be the same as masteries tests I guess. The board seems to work at least. Tested on a MegaST.

More info about the project can be found on github.

ACSI2STM v1.2 back.jpg (285.28 KiB) Viewed 3926 times

ACSI2STM v1.2 front.jpg (220.88 KiB) Viewed 3926 times