intric8 wrote: ↑Wed Nov 11, 2020 6:33 pm
I have a feeling this would not play nice with my Rejuvenator, but I could be totally wrong. It happens all of the time.
I don't see why it should not work with the Rejuvenator.
There might be some issues:
1. When using a TF or Vampires, the internal 68k CPU has to be removed, because it would still create the Eclk even when the internal CPU is put to HALT or BUS GRANT is used to disable it.
2. For the external Kick Flash I use the /OVR signal which is normally handled by the A1000 PALs or the A500 Gary to disable CHIPSELEC of the internal WOM/ROMT. As long as those are still in place and the memory area from 0xE00000 to E7FFFF is not occupied by other ROM, the Kick Flash should also work.
intric8 wrote: ↑Wed Nov 11, 2020 6:33 pm
Speaking just for me, since I have neither a TF or Vampire, can you explain a little bit more about the
"FPGA socket to use an FPGA as a CPU emulation"? That sounds very interesting. You might should consider making this board its own thread whenever your boards arrive. (Or, I think I can help with that now if you like.)
That is experimental. I want to use one of the QMTECH FPGA boards which you can find on AliExpress as a base, e.g. the QMTECH Intel Cyclone IV EP4CE55. I haven't started with the VHDL code, but the schematic and layout of the base board should be finished although not tested, yet.
intric8 wrote: ↑Wed Nov 11, 2020 6:33 pm
I think it would also be quite cool - since I'm just dreaming here - if the expansion could be easily disabled via hardware switch in case one wanted to load a game via floppy that has to be booted.
At the moment I placed 5 jumpers and one of them disables the Kick Flash at 0xF80000, but it leaves the range at 0xE00000 active to be able to do the flash programming while the active Kickstart runs from internal WOM/ROM. It is also needed, because the flash will be empty when it is delivered or probably flashed with the DiagROM.
intric8 wrote: ↑Wed Nov 11, 2020 6:33 pm
As an A1K fan that uses his expansion port today, my only concern would be if I could continue to use my Microbotics 2MB RAM that I also use for its SCSI port. That's how I boot via "hdd." I wonder if I could stick this board out of the Microbotics side port? Oh man that would look nuts, but it would be an interesting experiment for sure.
There are no buffers at the Zorro I bus (in contrast to Zorro II), so the load to the bus lines could become too high when too many cards are chained, but two should probably work.
intric8 wrote: ↑Wed Nov 11, 2020 6:33 pm
Not sure about you guys, but the expansion ports on some of my A1Ks can be a bit finicky at times if the connection isn't spot on. Sometimes how an expansion "hangs" on the outside can have a dramatic effect on it working, even if the angle change is a fraction of a millimeter.
I don't have an A1000 myself, that's why I additionally need an A500 connector for testing. So I have no experience with such problems.
Michael