Recent content by trag

They were not sophisticated enough at the time to explicitly discuss ROM versions. If the information is present, one would have to infer ROM versions from the discussion of Daystar sending out different versions of the Turbo601 to support various machines and functions.

Do you mean the Turbo601 boards? Have you browsed the "Unofficial Turbo601 HomePage"? I think it is only available on the wayback machine, now. It was hosted at something like brinhoven or some such. There were a lot of historical comments there as support was added for machines other than...

Thank you for your kindness. Now that you mention it, I layed in a small supply of those 7500/100 cards a couple of decades ago for exactly that kind of use. I had forgotten I have them. And yes, every single one of them has a blob of glue on the back that makes desoldering and clean up an...

Excellent work @zigzagjoe . My original work was just laying the two cards next to each other and changing the differences. It never occurred to me to change the multiplier from 3X to 4X and I did not know what the resistor changes were actually doing at the time. Your work is a vast...

The thing I've been missing in the listing is Macintosh clones. Those were thick on the ground back when. Now they don't seem to come up in listings and if they do, the seller thinks he's at Christie's. One difficulty is that PowerComputing was if not the largest, the most interesting clone...

Yes, I've been working with those chips so long, I just think of both modes without remembering I need to mention it. Under my scheme, the Xgecu would program the entire DIMM, but only one chip at a time. So programming a firmware DIMM would be a four step process.

I think that was before 2007, so almost 20 years ago. I think it was pretty similar to the listed prices. IIRC, the Serial Port version was near the middle of $100 and the Appletalk version was a little over. But I could be completely wrong. It was a package with one or more floppy...

Microspot is still in business. I have no idea if they still sell MacPalette II. mailto:sales@microspot.co.uk I bought the Appletalk version from them long after they had stopped marketing it, and they were happy to sell it to me.

I don't seem to have the Gerbers on line. It would be a bit of work to get them uploaded. I do my layout in Osmond PCB on a Mac running Classic. The memory chips are 16M X 4 FPM or EDO chips. The two smaller chips are a some kind of bus switch. It's been so long, I'll have to look at the...

Thank you folks. I'll give these ideas a try. I'm much more of a hardware guy. Will this work on Windows? I think the latest MAC OSX machine I have runs 10.5.

BTW, 100 pin QFP SRAM chips usable for cache, I believe, are still available at Digikey. For example: https://www.digikey.com/en/products/detail/rochester-electronics-llc/CY7C1347G-250AXCKJ/12105899 Minimum order quantities are a bear though.

I must be seriously out of date. How the heck does one download a useful disk image from that archive? I got the 700+ MB file just called "Bandit" but it doesn't seem to have any usable file type, such as ISO Image or such.

Faster SRAM cache chips still available, but one must order 42 at a time.... https://www.digikey.com/en/products/detail/rochester-electronics-llc/CY7C1347G-250AXC/12606500

I suspect they all are decoupling caps. The larger ones are further from the center of the PPC chip suggesting that they are simply larger capacitances, in a larger package. The only two things on a CPU card that might need a capacitor that isn't a bypass capacitor, I think, are the power...

I think there are sometimes Muxes 74xx151, 153, or 157, most likely, that take data from the VRAM chips and route it in the appropriate number of color/grayscale bits to the DAC. The logic on the video card controls the Muxes so that the right data from teh right VRAM chip(s) are used in the...