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There's not too much more testing to do on this card but I will of course have future Apple II products which need testing. I have a prototype design for a 6502 core which should eventually make its way into an accelerator card. I call the core Sweet65, in reference to the Apple II's Sweet16...

Well the photoshoot was easy enough although I didn't get the photos the way I like: The lighting is a bit odd and the board is slightly out of focus. Focus is supposed to be on the board, not the taller chips. I would also like the colors to be slightly different but no big deal. Good enough...

Hmm well the ROM is only 32 kB, of which only like 22 kB is used (i.e. not part of a big string of 0xFF bytes). So not too much but more than the minimum 1-2 kB required to boot a 68000 and do something useful. I haven't disassembled it though. Maybe later I'll put it into IDA and see what it does.

Ooh very interesting about the boot ROM and the FDHD incompatibility. Of course my accelerator has boot ROM integrated but it’s in the entire Mac ROM (since Apple doesn’t care anymore) as opposed to just a little bootstrap. So are you saying that the Prodigy ROM puts up the “question mark disk”...

Yes, it’s not as simple as just decoding the rest of the address lines. Nor is the 68851 or paging MMU in general really the secret sauce. It would be easy to make a circuit with a PAL or something that could re-map the addresses of the I/O chips and ROM, moving them out of the way so as to make...

My latest "innovation" on this project is this little JTAG update gizmo: Same circuitry as I have discussed in the WarpSE thread. And they're only $1.68 each assembled from JLCPCB (in qty 50)! I think it's the cheapest and also the slowest JTAG programmer in existence hahah... It only works...

Haha no big deal. I have been putting this card off for years. I think I first announced that I was developing it something like three years ago. It has been (partially) redesigned four times.... First version with legacy DRAM and CPLD... cancelled this prior to release because legacy...

Should be sooner than that lol. I can do the Classic RAM once I take the pictures, make the manual, and make the listings on the various ecommerce sites. So a few days; it's basically a function of the weather since I usually take them outside. Producing all the VRAM SIMMs will take many hours...

In my experience, I have rarely succeeded when throwing chips at a problem in lieu of doing all the continuity checks to verify the board wiring. I dunno if the buffers were broken in this case, since I did replace them, but I suspect they would have worked fine. I was just hoping I could...

Yeah we will be doing the bringup soon... just have to do a laundry list of things that make a bit of money sooner: Release first ~50 units of Mac Classic RAM (production just finished) Produce ~150 more 512 kB 70ns RAM SIMMs (they're running out) Produce and rerelease ~300 RAM2GS II and RAM2E...

Almost done :) Release will be soon. edit: Oh and I guess I forgot to say, they’re all tested and working. So all that remains is packaging and creating the manual and pictures.

I have not seen any for the 660AV so I don’t think they have been published. However the 840 and 660 are based on the same exact chipset and architecture so I’ve had success just looking at the 840 schematic and ignoring the stuff that I know isn’t on the 660

Yes! So on the 840AV when you install VRAM SIMMs in the slots, you are doing the same thing electrically as I did with the mod. I was inspired to do the mod after reading the Developer Note and the video init code which is run at startup. The video init routine measures the RAM size rather than...

I will be doing the bringup soon. Other stuff is ahead of the WarpSE in the pipeline at the moment.

Well yeah you could disable onboard video and use a card if that’s what you mean. But it’s probably better to track down the issue and it should be easy to fix if you can solder a wire to reconnect the broken points in the circuit.

I'd check all of the address bus, data bus, RAM bank A address, and RAM bank A control signals for continuity using a multimeter. You can refer to the Bomarc schematics, then use the multimeter in diode/continuity mode and make sure all of the connections "beep." This was how I found the issue...

It's fairly likely that it would. Apple had the "universal ROM" approach after the Iici where they tended not to remove stuff from the ROMs. That is to say that when creating a new machine they'd add more stuff to the existing ROM in order to detect and support the new machines while leaving the...

My thoughts: 128k - Digital board is pretty reliable except for the RAM. Old Micron, TI, and Apple-branded (made by Micron I think) RAM on the digital board often fails. Replacement with newer 64k DRAM chips solves the problem. Analog board tends to break due to heat issues. Flyback transformer...

It’s the HP L2335. 1920x1200 resolution. I like it a lot not just because our lab is HP themed but also because it’s an alright display. I believe it has the same panel as the old 23” Apple Cinema Display. These two were the first IPS displays to come to market. Nowadays there are screens with...

Not exactly. My older gizmo, pictured above and discussed in the accelerator thread, is basically the same thing as the PowerR adapter. This new schematic has a smart microcontroller in it with 264 kB of RAM. It’s supposed to use the RAM to store whole frames from the Mac, synchronizing each...