SuperSVGA's latest activity

It sounds like unstable power especially if it's inconsistent in how far it starts up. Are you able to check the +5V rail with a multimeter?

You would have to completely move them out of their current space from the code side in order to have contiguous RAM. This does...

Depends on how much RAM you want to add. What you would want to do is change where the CPU thinks the memory locations are (i.e. edit...

Without separating the CPU from the computer in order to rewrite addresses, you would have to move other devices on the bus to different...

It doesn't take much, the basic process is disabling the built-in ROM with the switch/jumper on the board, putting the ROM on a PDS...

The Disk ][ card did not have any PALs, it was all general logic and two PROMs. I fit it all into a single ATF1504 at one point...

Unfortunately the 68000 only had 24-bits of address lines connected. To address additional memory you would need to implement some sort...

The Portable tops out at 9MB (not sure about the PB100) but I moved the ROM higher into the memory space to make space for 15MB of RAM.

One thing I was thinking about lately, who has the most powerful/fastest/most capable 68000 Mac out there? I’m only counting the...

It's through the serial testing interface that's available in pretty much every single Macintosh with a serial port since the SE. The...

Since it's returning 2 that means it's the second ROM (I think that would be MH, I can't remember) that failed checksum and the others...

If switching to another known good ROM set doesn't work then it's probably an addressing issue. You're clearly getting far enough into...

The DIP-28 could definitely fit everything you need in roughly the same footprint. Here's a rapidly put together render: The PLCC-44...

If you're not intending to connect a physical disk drive you could probably just leave the programmable logic out and just use the...

It should be going between the two capacitor legs, it's not connected to the capacitor. That's just one of the serial port lines so it...