MOS tech 6502 8-bit microprocessor in pure SQL powered by Postgres

m000

Cool! How about Postgres on MOS tech 6502 8-bit microprocessor powered by Microsoft's 6502 BASIC?

Someone

This, basically, uses a table to store 64 kilobytes of memory, a single-row table for storing register values, and uses regular procedural programming to run the CPU ( https://github.com/lasect/pg_6502/blob/main/init/05_execute.... ) I give that an A+ for perseverance, but I would have hoped to see something that uses the strengths of SQL more. For example, there could be a table with the decode ROM ( https://www.cpcwiki.eu/index.php/MOS_6502#The_Decode_ROM_.28... ) that could be used to drive the logic. Have a main loop that uses the inputs of that ROM to look up the output bits and update a table, and add triggers that handle each “micro-op”. A SQL engine could run those triggers in parallel until they hit a race condition, but those can be avoided a bit by having separate tables for each register. Even better would be if there were tables with every logic gate and wire in the original CPU, using a trigger to move the signals around. That would be a good test of the trigger handling in a SQL engine.

anthk

Kim-1 emulator and assembler for T3X0: https://t3x.org/t3x/0/sim65kit.html https://t3x.org/kimuno/ Pocket calc as 6502 code https://t3x.org/kimuno/kimcalc.html T3x0 compiler to build the emulator: https://t3x.org/t3x/0/index.html I've got to run under OpenBSD/i386 but it needs a bit of tweaks in the Makefile. On the target section: # CFLAGS=$CFLAGS" -m32" # on x86 64-bit systems CFLAGS=$CFLAGS" -static" # in case all else fails CFLAGS=$CFLAGS" -fPIC" # get rid of stupid linker errors CFLAGS=$CFLAGS" -Wl,-z,notext" # get rid of stupid linker errors CFLAGS=$CFLAGS" -fno-PIE -no-pie" # get rid of stupid linker errors Do the same in the bin/tx0.sh and bin/build.sh just in case. In my system I set the target to unix-386, and T3XDIR it's set to T3XDIR=/usr/local/t3x/lib in the Makefile and bin/tx0.sh scripts. Also, T3XBIN it's set to BINDIR= /usr/local/t3x/bin Then I ran: sh bin/modpath.sh /usr/local/t3x/lib gmake all-native doas gmake install-native install-modules But it was still broken. Then, I edited /usr/local/t3x/bin/tx0 and set TX3DIR is above, and ditto with the four CFLAGS flags I posted. Just the ones at lines 38-42. OFC set PATH to /usr/local/t3x0/bin:$PATH in ~/.profile: export PATH=/usr/local/t3x0/bin:$PATH Yeah, it's tricky, but from now on everything will just compile with 'tx0 foo' where 'foo' it's a foo.t file. This was compiled under an Atom n270 CPU based netbook. I think the author uses a Pentium III machine. If T3X0 can do a MOS 6502 emulation that well, you can try expanding s65/sim65 to cover the Apple I emulation. And, as a plus, it might run fast on DOS 386 machines if s65/sim65 it's compiled a native binary.

larodi

Waiting for 6502 implemented on top of Sudoku!

eatonphil

Very cool! If you want to see a much simpler version of this I wrote an article a few years implementing a stack language in Postgres PL/pgSQL similar to what this one does. https://notes.eatonphil.com/exploring-plpgsql-forth-like.htm...

fred_is_fred

Can someone take this and build a working 6502 binary that creates a SQL database?

jpl56

Lovely! (I saw a few examples in "tests") Next step : insert the Applesoft Basic assembly code and allow programming in Basic through SQL