Cloning an A17 device is the most complicated task compared to any other PPS-4 components. Why? Just because A17s contain 3 subsystems and each will use the data bus differently. Which means that all 8 lines of data are bidrirectional. This is the reason why 3 boards are required to achieve the cloning (plus the socket). All other devices of the series may be cloned with only 2 boards.
Please, remember that original spider chips are essentially based on high side P channel MOS transistors. Moreover, they are powered in the range [0V, -17V]. This antique combination of data makes it impossible to find equivalent components. SN7407 for example would not be suitable because they are low side, or any other modern buffer, etc..
This is why the A17 clones are a little bit more expensive, and more complicate.
For this purpose you will need to make 4 boards
You will find below all the files and information you need to make your clone. It is a bit complicated to be perfectly honest. There are 4 PCBs whose one of them is a 6-layer PCB. The fabrication for only one clone might be expensive, even more expensive than buying them from us. So unless you have a good reason for doing everything by yourself, we recommand you to click on the button below.
This is the simpler one. Its purpose is only to fit clones in direct replacement on the Host board. It is also a good method to protect the host board. this socket is soldered to the host for once. The rest of the system can be pulled out for repair or anything. No need to unsolder a QIL42 once again. It is done once in the life of the host board. For maximum security, one can also solder sip female contacts on the host board, and then plug the socket onto it. Good strips of sub-miniature sockets are D01-9972042 from Harwin. They are secable to the number of contacts you need per row.
On this board are gathered all the circuitry required for the management of the pps-4 system: addresses, data, clock, control signals. The voltage level translation is also done here. Power supply for the other boards is also performed here.
This board is dedicated to I/O management
This is the main board in the system. The one which contains all the VHDL equations corresponding to the given chip to be cloned.
Starting from 2023-10-15, we publish the Spartan 7 based design only. With the raise of Covid 19, the prices of electronic parts started to climb extraordinarily. The cost of Spartan 3 chips became comparable to the one of Spartan 7s. Besides, Spartan 3 are no longer supported by Xilinx, hard to find, and ISE14.7, their only available programmer, is a real pain in the back. Should you need information on the Spartan 3 soluion, please contact us with thee contact sheet.