Recent content by mdeverhart

This unit has the on-board Ethernet (connector to the right of the SCSI port), which I’m 99% sure means it has the full 040 with FPU, rather than the LC040 without.

The main thing is that tantalums should be derated by 50% for the voltage rating - if the capacitor will see 5V (like a decoupling capacitor connected to 5V and GND), then you should use a capacitor with a minimum voltage rating of 10V or more. The biggest drawbacks are with their failure modes...

I had the same problem on my Centris 650 - it was infuriating! I had numerous times where I’d install 7.6, reboot, install the 7.6.1 update, reboot and… corrupted. Or I’d get it installed and then start un-stuffing a bunch of files (games installers), and then… corrupted again. The recent...

Great, thanks! That’s perfectly reasonable 😃

Are the design files for the Duo pack posted anywhere? If not, would you mind sharing? Thanks!

How easy was it to import the text in the first place and structure it appropriately? How was the source data formatted, and did you need to do much massaging to fit the desired database structure?

My point (which I probably muddled), was just that I’m skeptical there’s much of a market for replacement SE ROMs, other than maybe as a repair part. Clearly that’s just my opinion, and I don’t have any data one way or another to back it up. That said, it sounds like it would be the same...

Hmm… if the SWIM weren’t required separately - maybe? With the SWIM I feel like you’re talking $50-60+, plus the cost of a SuperDrive. Generally speaking, I feel like you’re going to have two camps: 1. Folks that are generally content with the machine as-shipped (or prefer the original...

Cool! Looks like really good work! Seems like you put together a nice framework for this type of application/database.

Thinking about this some more, you could also do dynamic adjustments to the refresh probability - every time you don’t opportunistically refresh but could have, you increase the refresh probability; every time you do opportunistically refresh and shouldn’t have, you decrease the probability. You...

It’s probably possible that you could do a statistical analysis of the ROM to determine which percentage of instructions will touch RAM on the following access - loads, stores, operands in RAM (based on the addressing mode), etc. You could then tune a refresh strategy based on the likelihood of...

Those will probably be connected back to the CPU or the Memory Decode Unit, but I’m not sure which. SEL is the chip select so that the SCSI chip knows the CPU is trying to talk to it, and DACK (Data ACK) signals back to the CPU that the CPU read/write to the SCSI chip is complete.