#garfield Logs

Apr 26 2022

12:29 AM rue_mohr: ok, thing designed and printing
12:38 AM rue_mohr: I can play with it after work tommorow
04:49 AM Tom_L: .
07:41 AM aandrew: heh, insanity circuit on twitter, our boy rue_mohr called out almost immediately: https://twitter.com/sad_electronics/status/1518879582602080256
08:32 AM rue_mohr: heh
08:32 AM rue_mohr: its a funny one, I'd done it before tho
08:33 AM rue_mohr: its the feedback on the unfiltered side thats key
11:20 AM WormFeud is now known as WormFood
01:41 PM polprog: lol, it is a very clever circuit
01:42 PM polprog: my friend at uni asked me if one can make a boost converter with the 78xx series regulators
05:17 PM aandrew: man mips assembly is killing me
05:19 PM aandrew: MIPS (r5000) docu says boot vector is virtual address 0xbfc00000 which is just KSEG1 (uncached) 0x1fc00000. my bootrom is only 512k so it's all aliased to hell but it just means that the ROM vector is at offset 0
05:19 PM aandrew: offset 0 is a j 0x388 instruction followed by a NOP. so far so good
05:20 PM aandrew: and the code at 0x388 certainly looks bootish (mtc0/mfc0, bunch of what looks like init)
05:20 PM aandrew: MIPS docu also says that the syscall instruction should jump to the general exception vector, which should be 0x180
05:20 PM aandrew: ok fine, instruction at 0x180 is a jump to another address, so far so good
05:21 PM aandrew: the first instruction at that address is "jr $ra" which if I understand correctly, just jumps back to whatever executed the syscall instruction
06:07 PM rue_mohr: hmm
06:07 PM rue_mohr: the system I was tearing into...
06:07 PM rue_mohr: no I dont think it was mips
11:45 PM Tom_L: so non productive today.