Post B57QuPB6XTWMcnuJuK by hp@mastodon.tmm.cx
 (DIR) More posts by hp@mastodon.tmm.cx
 (DIR) Post #B57QuO5ObDMPEoEFN2 by mos_8502@studio8502.ca
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       Building a countercomputing computer requires that every part be understandable and available to anyone. That’s why RISC-V is out. It should be the winner, but there’s no discrete CPU to buy, just complex proprietary systems-on-chip. DISQUALIFIED. Same for x86. PowerPC? ARM? DISQUALIFIED. You see the problem. At least the eZ80 can just be bought at Mouser. I can buy the 65816 direct from WDC.
       
 (DIR) Post #B57QuOXktm2selUtZg by hp@mastodon.tmm.cx
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       @mos_8502 I think FPGAs are the only way;You're going through the 5 stages of "no CPUs with external memory busses grief" that I've gone through. Based on my research the only vaguely viable options of parts for which a lot of NOS exists is * I960* 68k (with 24 bit memory bus)Based on my research (and I really did spend months looking at options) those are the only available chips with external memory busses and capable of supporting an MMU.And they'd still need an FPGA as chipset
       
 (DIR) Post #B57QuOxdLYkHx1bYuW by mos_8502@studio8502.ca
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       If you have to scavenge the parts it’s hardly available to all, now is it?
       
 (DIR) Post #B57QuPB6XTWMcnuJuK by hp@mastodon.tmm.cx
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       @mos_8502 with the xc7 and ECP5 there's open tooling to do it, and the ECP5 exists in tqfp-144 which is achievable at home with a heat gun, solder paste, and patience (or is VERY cheap to have placed by a fab, no x-ray necessary!)But the i960 has the same problem.Only the 68k doesn't, but then you're limited to 16mb of ram. The "full fat" 68ks are unaffordable (and largely UNAVAILABLE for any price)Plus they'll run out.So I think that leaves i960 or fgpa.
       
 (DIR) Post #B57QuPnOF896XXotaC by mos_8502@studio8502.ca
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       I would love to have an easy way to build a fully open hardware 80386. It doesn’t exist. So we have to make do with what exists.
       
 (DIR) Post #B57QuQc5CehB4lXNb6 by mos_8502@studio8502.ca
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       It’s not about asceticism, it’s about practicality meeting the point of the exercise.
       
 (DIR) Post #B57QuRIydB0TDnbdSK by mos_8502@studio8502.ca
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       Reusing existing case and power supply standards is sensible. There’s no one company that controls those things, there’s no shortage of supply.