Another IIci ROM hack

[dougg3]

The programmer PCBs just shipped. If my last UPS shipment is typical of what to expect, they should be arriving later this week.

I also just placed my (final) order for 100 ROM SIMM PCBs since I only have one of the rev. 2 boards left (aside from the one I lifted the pad on). I made one final change at the request of bbraun to make it easy to add a switch that allows you to change the mapping so you get either the top 1 MB or lower 1 MB of the ROM space. 100 of them should be enough to last us for a while!

Also, page 26

[techknight]

goodie! I woudlnt mind having one of those with a SIMM to mod my SE/30.

Edit: Dumb question, What is the minimum block write size of the Flash ICs your using? Just wondering because i hope the AVR has enough RAM to buffer a block write. Well i guess it doesnt matter as long as the serial data can keep up.

[bbraun]

Woohoo, I'm looking forward to these things!

Also, the SE/30 is fun to have a working image with the ROM SIMM. The SE/30 is the worst for access to the SIMM slot.

[Trash80toHP_Mini]

Bump! And another page bites the dust! Bump! Bump!

I was wondering if the programmer would be able to handle something like reading the DeclROM of the Duo MiniDock (PLCC or some such) and then burning it onto a ROM compatible with the original DuoDock?

I have a sneeeeeeking suspicion that it may well work with the the little dog's bits installed, so's the Big Dog's Dock Services and the LCD would be enabled at the same time if booted in that config. We know that the NuBus ChipSet's function is independent of the Big Docks DeclROM because the slots work if it, or its power, are pulled.

Sooooo, the next step would be . . .

[dougg3]

Cool Well it'll take a while to write the firmware for it! Haha. I have some electrical test code written and I'm anxious to test it out.

The chips are writable a byte at a time. They have to be erased in 128-byte sectors, though, but that's not a big deal.

I haven't thought a great deal about performance, so we'll see how that goes. I'm hoping I can fit a bootloader on it to allow for firmware updates over USB. Hopefully the USB stack (I'm thinking about using LUFA) won't use up all my resources.

The AVR I'm using is the AT90USB646, with 64K of flash and 4K of RAM. I think if that ends up not being enough, I can switch to the AT90USB1286, which would have 128K of flash and 8K of RAM. I'm pretty sure I can make it all work with the smaller chip though, assuming the USB stack isn't a huge memory hog.

No idea on the DeclROM compatibility. I suppose if it doesn't fit the pinout of the chips I'm using, you could run wires from the pin header to hook it up correctly...

[Trash80toHP_Mini]

Cool, that or the low rent/fugly approach in an "emergency!" Wire wrap jumpers from a de-populated Socked SIMM's expansion Vias to a breadboard setup.

Me likes FUGLY!

[dougg3]

Looks like the PCBs will be here tomorrow. There's no "scheduled delivery date" like you would see on most packages, but it left Anchorage a couple of hours ago. Based on flight tracking websites, it appears they are probably en route to Louisville, which would indicate overnight delivery tomorrow...

Yes, I am that obsessed with knowing where the package is

I'm very, very anxious just to get a "blinking LED" program onto the AVR to see if my board design actually works.

[dougg3]

In actuality, it went through Ontario, California rather than Louisville. I guess I saw Ontario International Airport and figured that meant Toronto...oops! Anyway, the programmer PCBs have arrived:

[Trash80toHP_Mini]

It's beeeeeauutiful!

[dougg3]

I'm not bothering with the RS232 circuit yet:

It's drying now, but before I washed it, I powered it over USB and hooked it up to my AVRISP mkII programmer. It recognized the chip successfully Always a good sign...

[dougg3]

The board is alive, blinking the LED on and off. Unless I have any shorted/loose pins, I think I'm in business I guess I haven't tested every single functionality of the device yet, but the microcontroller and clock circuitry seem to be working fine!

Even though I only ordered 50% electrical testing, it looks like they did 100% testing because all 10 boards have a mark on them. That's nice of them!

[olePigeon]

SIMM sockets should be there soon... but it is the holiday shipping season.

On a side note, I had no idea you could ship live chickens via the USPS.

[dougg3]

Awesome! Thanks! I still have a lot of work to do before I can even do anything with the SIMMs, so it'll keep me busy for a while

Ok, now you have me a little worried...did you send me a live chicken along with the sockets? LOL

[olePigeon]

Christmas Goose was too expensive.

[bigmessowires]

Awesome! I haven't been following the programmer board details very closely... what kind of microcontroller did you end up using? Does it have native USB, or are you using an FTDI chip, or how exactly is your USB connection made?

[dougg3]

I'm using the AT90USB646. It's native USB, so I'm going to use a USB library such as LUFA to make it a USB CDC class device. Essentially a serial port that is driverless on OS X and Linux, and requires a simple .INF for Windows that only tells Windows to load its own built-in serial driver. I decided against the FTDI chip because it's pretty expensive compared to the microcontroller's price. Anyway, I haven't tested any USB stuff yet other than for supplying power, but I did notice when I plugged it into my computer unprogrammed, it appeared as a USB device with Atmel's vendor ID -- so the USB circuitry probably works. I *think* that was a USB bootloader built into (or pre-flashed onto) the chip.

Latest update is it also appears that the SPI I/O expander chip is working! Struggled with it until I realized the bits in the data direction registers on it (1 = input, 0 = output) are backwards from the AVR's (0 = input, 1 = output)...ooops! My electrical testing code works now, and it should also be useful for testing the programmer board itself for shorts...

[tt]

That's so awesome Doug. The design is really elegant. I'll have to look into that AVR chip. I'm glad someone was able to find you some SIMM sockets, too bad the ones I found were a dud.

[dougg3]

Thanks tt! I appreciate your effort toward looking for the sockets even though it didn't work out They seem pretty hard to find these days. Luckily olePigeon somehow found a place that has them!

[olePigeon]

No big deal. We have lots of chickens in California... err, I mean sockets.

[Dog Cow]

On a side note, I had no idea you could ship live chickens via the USPS.

They ride up front in the cab with the driver.

[dougg3]

They ride up front in the cab with the driver.

So, I have to ask, olePigeon, how did you find that random tidbit? Was someone at the post office mailing some chickens?

[olePigeon]

There were three boxes of live chickens on the sorting counter at the post office. I kept hearing clucking, but I was like... naaaah. Couldn't be. Then the postman came in and grabbed the three boxes, and there was the unmistakable clucking of chickens. It got quiet, then everyone in the post office laughed.

[dougg3]

Haha, that's awesome! I naturally had to Google it, and I see there are places where you can order chickens, ducks, turkeys, etc. and have them shipped to you...weird!

On a more serious note, the USB circuitry on the board is working fine too. I have it working as a USB serial port. Like I said, it requires a really simple driver on Windows, and works out of the box on OS X and Linux. I've tested it on all three At this point it comes down to writing the software and hoping that the USB serial performance is fast enough...

OS X recognizes it as a modem...hopefully there's a way to turn that off. It's kind of weird.

[techknight]

well as long as that modem has a "physical" port address that is controllable in a development environment, it doesnt matter.

[dougg3]

True, and it does have a TTY device in /dev (tty.usbmodem223 in this case -- not sure what the 223 stands for). Also, after I went into Network System Preferences and clicked "Apply", it looks like it quit whining to me about a new network device every time I plug it in. Excellent

olePigeon's SIMM sockets arrived! Woohoo! Here is a SIMM socket soldered to the completed board (other than the RS232 stuff) with a SIMM inserted:

It looks like my electrical testing routines work All of the SIMMs I have recently built are showing up perfect, and I have some older SIMMs I assembled while I was messing with solder paste that I know have shorts, and they fail the electrical test. The only thing waiting now is for me to write the firmware and software to communicate with it, and then this sucker will be ready to go...