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I just don't think the Portable ROM is "universal" like the later Mac II ROMs are. I'm not sure it can boot the SE without major modifications. This would make sense since the SE and Portable have totally different memory maps, so what would be the point of Apple making the Portable ROM work on...

Reimplementing the BBU has been a much-discussed topic on here. Whenever it comes up, I always suggest that we should be focusing not on a form and function replacement for the BBU but a redesigned Mac SE motherboard using modern RAM and FPGA to implement the BBU and RAM. Thanks to @Kai Robinson...

Too complicated! I think it's better to use the memory-mapped frame buffer approach than piping the commands over SCSI as the ScuzzyGraph does. And as for the MagicBus connector, I think we have to reject it in favor of the in-line expansion approach or nothing if there's not enough room. It's...

Lemme check my SEs and see how many have the have the hole for the vertical card. Yeah, lemme see how close it is when all stacked together. If it's not too tight then I think the horizontal card will work best. I'll have to see. Yeah, SE doesn't really do Color Quickdraw so only 1-bit is...

Yes, yes, that's what I meant by "Current layout doesn't support anything but the vertical PDS extension right above the existing one." Issue is that the whole stack might be too tall with a vintage PDS card installed above the WarpSE. Either way, we can do small, thin cards with this kind of...

Hmm interesting approach with the vertical cards, both as suggested by mg.man and Trash80. Current layout doesn't support anything but the vertical PDS extension right above the existing one though. There's not enough room in this critical dimension in the layout: Everything would have to be...

Hard to compare the 'HC000 and the '030... It just depends if you need actual memory bandwidth or whether everything can fit in cache. Similar example is Ethereum mining. It's all memory bandwidth and you can basically divide a GPU's memory bandwidth by the amount of data required per hash and...

One last thing before prototype time... gotta make this little gizmo to connect an SE mounted on a board of wood to a monitor and ATX power supply: Prototypes sooonnnnnn I promise :)

Yeah look here on a stock SE. Can’t use the Monitors control panel and it’s not even included in even the full install for just SE. So if there is a control panel for a display driver, it’s probably a 3rd party one.

My plan to support the accelerator was to stick a little 3M Bump-On rubber foot on the bottom, positioned directly over the MC68000 on the motherboard. Is it really worth it to widen the card so as to be able to use the standoffs? It really would have to be that wide to go over to the standoff...

Are you supposed to be able to use the Monitors control panel on 7.5 an SE? I can't remember; haven't used one in a while.

Schematic would be kind of hard to make but I can add some more instructions: Stacking the VRAM chips The mod requires eight stacks of two 128kx8 VRAM chips in SOJ package. 256kx8 will not work! Make sure to use 128kx8. I used Micron MT42C8128DJ-7 VRAM chips but others will work too, as long as...

If you have an oscilloscope (oughta be 300 MHz or more) you can try verifying some of the basic specs of the MC88916, particularly the PCLK and BCLK frequencies, duty cycles, phase alignment, etc. If those look good the that the limiting factor must be the CPU or chipset, not the clock...

Nope, sorry, not yet. I don't even have a prototype yet. Should be out in a few months. Ooh yes... but will the motherboard+card+card stack fit in the chassis? No layout changes are needed so I'll try it! All existing cards should work except those which do DMA. Supporting DMA is possible but...

Yeah I think it’s the same person. I’m probably confused due to being up all last night.

Regarding the PPC VRAM, when you say Silicon Insider do you mean PurpleRAM? The PurpleRAM boards look good but I am a bit put off by the presence of 3.3V chips on his listing photo. My Power Mac 7200 has 5V chips and I don’t think 3V is right. I guess it works—maybe it’s even faster when running...

It’s possible but I haven’t worked out the specifics. In VRAM the OE pin is called “OE/DT” meaning that it has an additional function multiplexed onto the same wire. So you have to apply a slightly more complex circuit gating the OE signal. Lemme try and work it out and I’ll post in a different...

Okay! The prototype design is complete now, I think. I’ve checked all the pinouts and such. Looks good! The schematic is attached to this post for anyone interested to look at. I’ve also got an interactive HTML assembly guide too. The final thing I added to the WarpSE is a few extra wires to...

Nope, not yet. My methodology is a little bit more "waterfall" as opposed to "agile." I could pull the trigger on the hardware now, but what if there's an issue with the hardware that presents itself during software development? It's not too expensive to respin the board but I find it better to...

On the subject of VRAM, does anyone know if the LC 575 and similar can be used with EDO VRAM? It’s not officially supported or discussed since EDO VRAM was a later development than the 575. Were it possible to use EDO VRAM, I could make a 50ns 512 kB VRAM SIMM using a single VRAM chip. If we...