Thought I'd try and explain my universal card a little better.
It requires an FPGA with lots of GPIO pins. Every pin is brought out to 0.1" edge connections at the four sides of the card.
You pick it up and shove a Nubus card connector onto the bottom. Four microswitches mate with little notches you've previously cut out of the Nubus connector and provide a 4-bit ID. The card recognises this and loads the "I am a Nubus card" module into the FPGA. This contains the Nubus pin map, and the FPGA configures all pins correctly for a Nubus slot. It also contains a Nubus controller emulator.
Similar things happen if you plug an LC PDS/ 68k CPU male/ 040 PDS etc connector into the bottom edge.
You do the same at another edge with an ISA (or whatever) female connector. It loads the "ISA host" module.
Taking the case that you'll be using it today as an IDE drive controller, the following happens:
It pretends to be a known SCSI card to the Mac. Thus existing SCSI drivers can be used on the Mac side.
It configures itself as a DOS machine as far as the ISA card is concerned, and loads existing DOS IDE drivers.
In this way it acts as a middleman between the host Mac and existing, readily available ISA cards. This (in theory) takes a lot of the hardware and software development pain out of the loop. As time goes on, patches could be developed to allow it to natively support IDE drives in pretend-SCSI-PDS-card mode, and other functions as time and imagination permit.
Comments are welcome.
It requires an FPGA with lots of GPIO pins. Every pin is brought out to 0.1" edge connections at the four sides of the card.
You pick it up and shove a Nubus card connector onto the bottom. Four microswitches mate with little notches you've previously cut out of the Nubus connector and provide a 4-bit ID. The card recognises this and loads the "I am a Nubus card" module into the FPGA. This contains the Nubus pin map, and the FPGA configures all pins correctly for a Nubus slot. It also contains a Nubus controller emulator.
Similar things happen if you plug an LC PDS/ 68k CPU male/ 040 PDS etc connector into the bottom edge.
You do the same at another edge with an ISA (or whatever) female connector. It loads the "ISA host" module.
Taking the case that you'll be using it today as an IDE drive controller, the following happens:
It pretends to be a known SCSI card to the Mac. Thus existing SCSI drivers can be used on the Mac side.
It configures itself as a DOS machine as far as the ISA card is concerned, and loads existing DOS IDE drivers.
In this way it acts as a middleman between the host Mac and existing, readily available ISA cards. This (in theory) takes a lot of the hardware and software development pain out of the loop. As time goes on, patches could be developed to allow it to natively support IDE drives in pretend-SCSI-PDS-card mode, and other functions as time and imagination permit.
Comments are welcome.