Pinned toot

Introductions 

I don't know if the oldbytes instance is big on introductions, but if so, here goes!

I am a Seattle area nerd interested in the small internet. Back in the day, I spent a lot of time as a forum moderator, and I feel like social media has become much bigger, louder, and less interesting since then. Perhaps Mastodon does better?

I'm probably not going to post a lot, but if I do, it'll be about my adventures with dawless music production and doing strange things with old technology. During lockdown I have collected lots of new gear and am still working out how best to make tracks with it. and (mod, xm) are my home turf.

If you like to do musical things, and/or want someone to listen to your tracks, please by all means @ me.

forth, self-modifying x86 pitfalls 

I can't recall last time I spent so long debugging eight assembly instructions... and all because x86 has no "int [r8]" instruction (sigh)

Anyway, a previous revision of this code worked only when "intx" was stored at an even memory address. The reason is that even writes flush the instruction cache on 80186, while odd writes do not, and therefore a stale interrupt target is used. The solution? Add "jmp flush" to manually flush the instruction cache, as shown below.

INT:
push ax
mov ax, [bp] ; get X, top item on stack...
mov byte ptr [intx], al ; ...modify code to call interrupt X
jmp flush ; ..."useless" jump flushes instruction cache
flush: ; (see Agner: optimizing_assembly.pdf)
pop ax
db 0cdh ; "int"
intx: db 03h
sub bp, 2 ; pop X from stack
ret

In related news, I'm finally able to interact with DOS and the video BIOS!

These two make a good team.
I just need to get SLIP going, to let the CHIP bridge the 200LX to wifi.

Stupid trick: cable it up to a USB audio interface. Presto, now you have a tiny multitrack audio recorder!

psf boosted

In this episode Chief O'Brien repurposes the station's computers to mine bitcoin but also finds an unexpected love.

Introductions 

I don't know if the oldbytes instance is big on introductions, but if so, here goes!

I am a Seattle area nerd interested in the small internet. Back in the day, I spent a lot of time as a forum moderator, and I feel like social media has become much bigger, louder, and less interesting since then. Perhaps Mastodon does better?

I'm probably not going to post a lot, but if I do, it'll be about my adventures with dawless music production and doing strange things with old technology. During lockdown I have collected lots of new gear and am still working out how best to make tracks with it. and (mod, xm) are my home turf.

If you like to do musical things, and/or want someone to listen to your tracks, please by all means @ me.

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