TashTwenty: Single-Chip DCD (Hard Disk 20) Interface

[Tashtari]

Where can I download the HEX-files for the firmware for the 1825?

Right here. I still need to upload a hex file for the 1704, that release was from before I did the 1704 firmware which is why it isn't called out as being for the 1825.

Which IDE and compiler do you use to compile the firmware?

I actually use MPLAB 8.92, the last version before MPLAB X, because I strongly dislike MPLAB X and am a total stick in the mud. =D I don't recommend this approach, however.

tried to compile the firmware with MPLAB X IDE but I get an error with the file P16F1825.inc and the build stops.

What's the error?

 

[warmech]

Right here. I still need to upload a hex file for the 1704, that release was from before I did the 1704 firmware which is why it isn't called out as being for the 1825.

I actually use MPLAB 8.92, the last version before MPLAB X, because I strongly dislike MPLAB X and am a total stick in the mud. =D I don't recommend this approach, however.

What's the error?

I had the same issue; X says the INC file is missing (and indeed it was in my case). My experience with X was less than favorable, so I did exactly what you did and downgraded. Had no issue after that.

 

[Tashtari]

This is just a guess on my part, but it might be that the old-style .mcp project file gives the absolute path to p16f1825.inc which is correct for MPLAB 8 but might not be for MPLAB X. I'd try removing it from the project and then re-adding it manually the way that MPLAB X expects you to (whatever that may be).

 

[dochilli]

Thank you for the link to the HEX-File. I tried to flash the 1825 with a TL866plus, but a mac plus with a 6.08 boot disk does not see the HD20. I used the image with two drives. The SD-Card has 4.86V at VCC.
I think that there is a problem with flashing the 1825. Up to now I only worked with eproms and had no problems with the TL866 plus. Any ideas what I can do?

 

[cheesestraws]

had no problems with the TL866 plus

I've had no luck flashing PICs with my TL866 at all, and in fact managed to (I think) brick one. Ended up getting a cheap clone pickit3 on eBay. If you were using the 866, I'd look at the flashing as the likely cause, indeed.

 

[Tashtari]

The SD-Card has 4.86V at VCC.

I'm assuming/hoping you mean that the level shifter board has 4.86V at Vcc and not the card itself, since SD cards are 3.3V devices...

I tried to flash the 1825 with a TL866plus

Yeah, what @cheesestraws said - I don't trust anything else but Microchip's own programmers (and clones). PICkit3s go for around $20 on ebay these days, since they're previous generation (but will program the 1825 and the 1704).

 

[dochilli]

Yes, 4.86V at the level shifter board.
I downloaded MPLAB 8.92 and now I can build the HEX-File. A Pickit3 is ordered. I had a Pickit2 but it will not work with the 1825. Now I am waiting for the pickit3...
Thanks for your help!

 

[Zhinü]

I may have an HD20 to slot one of these emulators in now. Coming up with a communication error involving hi->low busy signals. So, might be a good candidate for a swap.

 

[Tashtari]

Working on assembling the kits. Still need to cut a bunch of IC tubing and program a bunch of PICs to put in it, but here's a progress shot:

 

[Zhinü]

Working on assembling the kits. Still need to cut a bunch of IC tubing and program a bunch of PICs to put in it, but here's a progress shot:

View attachment 41647

Oooo, can’t wait! Speaking of that, does anyone know how where I should mount a SD card extensions inside of my HD20? The gaps in the case aren’t big enough to fit one without having the main non-ribbon cable part sucking out.

 

[Tashtari]

The first wave of kits has been mailed! Looking forward to everyone's builds.

Kits are still available - click here for pricing and information.

 

[Tashtari]

does anyone know how where I should mount a SD card extensions inside of my HD20?

You could always have it poke out the back where the "DB"-19 female connector is.

 

[Zhinü]

You could always have it poke out the back where the "DB"-19 female connector is.

I'll have to try that, thanks!

 

[ErinRF]

Kits arrived last week and I finally got to putting them together!

I tested them on my Macintosh SE and the Tashtwenty tiny works great, though sadly the red Tashtwenty rev1 didn't seem to want to work. I haven't had time to investigate why.

The full size SD card socket went in very nicely with those registration, easily my favorite part to solder. All the lead bending and board flipping to get at the solder points reminded me how much I appreciate surface mount components!

I do enjoy the flickering LED on the tiny board quite a bit, well done!

 

[Tashtari]

So... I think SparkFun has sold me a bunch of bad level shifter boards.

@ErinRF 's board isn't the first one to have trouble, and it made me wonder if a pattern was forming, so I grabbed one of the kits I'd packed and assembled it myself, and sure enough, it didn't work. Curiously, it did work intermittently when I attached my logic analyzer to it, but that is not exactly a satisfying resolution. The rest of the time, the signal from the SD card changed at times that it shouldn't, and appeared to bounce between low and high. Signs that the culprit is the shifter board. Sigh.

I've made another board, this one using an SD level shifter from Adafruit rather than SparkFun, and sent it off to be fabbed. It will take a couple weeks to get the boards and the stuff necessary to make them into kits, but this TashTwenty Rev 2 board will replace the TashTwenty Rev 1 board. It'll be $17 instead of $15, as the Adafruit level shifter board is more expensive.

If you have a TashTwenty Rev 1 board from me, I'll be in touch to arrange replacing it at my expense, either with a kit for TashTwenty Tiny (immediately) or with a kit for TashTwenty Rev 2 (when the boards come in), whichever you prefer.

 

[Zhinü]

Stupid question, but does anyone know where I can find build instructions? I’m currently going off of photos but would like to know specific locations for resistors and all that.

 

[Tashtari]

build instructions?

You can find correspondence between parts and board locations here. Note that on the 1.0 rev of the board, the R2 callout points to the wrong outline - the five resistor outlines on the left side are, in order from top to bottom, R12, R1, R2, R10, R11.

 

[Zhinü]

I've assembled the kit I got and unfortunately ran into some issues. When plugged into my 512k, the power LED came on but no access happened, even with the HD20 boot disks. The HD20 test fails instantly, saying "Init Driver Failed -> Rene Driver." I can't tell if it's my SD card or my soldering. The access LED did not flash, but it could be because of the LED extensions I had added for installing into an HD20's case. Does anyone have an MBR image I can flash to my card?

 

[Tashtari]

Thought I had uploaded this before, but apparently I hadn't... this zip file contains known-good SD card images for the 1704 and 1825 firmware. Before trying anything else, try writing the 1704 image to your SD card and see if it boots.

 

[Zhinü]

Wrote that image to a floppy disk. The system does detect drive now when I use my HD20 disk, but then gets stuck on the "Welcome To Macintosh" screen and flickering. When booting a disk without the HD20 program, it does not pop up at all on Finder nor does it request to be formatted. Running the HD20 Test results in the activity LED flashing once, then saying "Unit Fails to Hard_Reset."