Re: exxos blog - random goings on
Posted: Tue Jun 18, 2019 9:56 pm
I keep thinking about a alt-ram card.. I did add it to a SEC design, but each time I do a new board, I would have to solder more stuff , larger boards, more parts.. it just gets annoying so alt-ram never gets done.
I just un-forgot I designed this a while back...
The header would be to branch to whatever does the decoding.
Though I am now thinking if I could put a small PLD on there as well, ATF1502, it has 32 IO's (and 4 extra for the JTAG).. So it should be enough as I only really need to route the address lines, 4 SRAM lines, DTACK & AS.
I'm mostly just getting sick of not having a alt-ram card to test stuff out with, like the SEC booster and GB6 in fact. With its own PLD, it could be used on the ST as a stand alone board. Problem with this board layout, is no way to plug the CPU into this board.. it would have to be soldered ontop of the 68000 for example..
If I made the board longer I could flip the chips and then get a socket.. though I will probably go mad if I route those SRAM's again
I just un-forgot I designed this a while back...
The header would be to branch to whatever does the decoding.
Though I am now thinking if I could put a small PLD on there as well, ATF1502, it has 32 IO's (and 4 extra for the JTAG).. So it should be enough as I only really need to route the address lines, 4 SRAM lines, DTACK & AS.
I'm mostly just getting sick of not having a alt-ram card to test stuff out with, like the SEC booster and GB6 in fact. With its own PLD, it could be used on the ST as a stand alone board. Problem with this board layout, is no way to plug the CPU into this board.. it would have to be soldered ontop of the 68000 for example..
If I made the board longer I could flip the chips and then get a socket.. though I will probably go mad if I route those SRAM's again