ChanServ changed the topic of ##yamahasynths to: Channel dedicated to questions and discussion of Yamaha FM Synthesizer internals and corresponding REing. Discussion of synthesis methods similar to the Yamaha line of chips, Sound Blasters + clones, PCM chips like RF5C68, and CD theory of operation are also on-topic. Channel logs: https://freenode.irclog.whitequark.org/~h~yamahasynths
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<cr1901_modern>
ej5: I had to do some equations by hand... I remembered something important >>
<cr1901_modern>
contrary to your handy chart of equations, the Voltage across a capacitor does _not_ equal V = q*C
* cr1901_modern
really needs to practice more
<cr1901_modern>
-
<ej5>
hahaha i forgot about that thing
<cr1901_modern>
I'm sorry I brought it up :P
<cr1901_modern>
Also very apparent: I've gotten _extremely_ sloppy with hand-writing out equations b/c I use the computer too much T_T
<andlabs>
now how do we trick electroboom into blowing something up by thinking V=q*C
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<balrog>
Foone: oh god those SunPCi cards
<balrog>
at one point in the late 2000s I tried to figure out how to make a lab of 30 of them useful
<balrog>
it didn't go very far :(
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<andlabs>
30?
<andlabs>
how many machines is that?
<Lord_Nightmare>
Foone: !!!!
<Lord_Nightmare>
Foone: apple2 pc transporter has an early SWIM chip on it (possibly an early, buggy die revision) which people call the "ISM"
<Lord_Nightmare>
since pc transporter was not an official apple product, instead of having an apple number like 342-0061-A on the SWIM chip, the chip is marked '010-1010-1'
<Lord_Nightmare>
this is the first place the SWIM was used, even before the apple2, macII-fdhd and mac SE FDHD
<Lord_Nightmare>
there's been a ton of discussion about the SWIM in the bannister shoutbox/shoutchat over the past 2 weeks, Sarayan is working on/has mostly finished emulating it
<Foone>
Lord_Nightmare:very neat!
<Lord_Nightmare>
intersting fact: the apple IIgs internal ROM has SWIM support (for at least rom03)
<Lord_Nightmare>
but the IIgs never shipped with a SWIM, only an IWM
<Lord_Nightmare>
the unreleased rom04/mark twain prototypes DID have a SWIM
<Lord_Nightmare>
can you transplant a PLCC SWIM into a IIgs rom03 and solder it in place of the IWM? ... probably yes!
<Lord_Nightmare>
i don't know of anyone who has tried this
<Lord_Nightmare>
if you do it, you should be able to use a 1.44mb superdrive on the IIgs without the superdrive adapter card
<Lord_Nightmare>
but it might be buggy as it wasn't an officially supported configuration
<Lord_Nightmare>
apparently the ISM on the pc transporter can be replaced by a PLCC44 swim if it fails, i think henry courbis from reactivemicro did this
<Lord_Nightmare>
which to me implies the ISM is really just a remarked swim, or possibly an older die rev where some features (maybe the IWM backwards compatibility stuff) doesn't work
<Lord_Nightmare>
and since apple and applied engineering worked closely together (many crossover employees)
<Lord_Nightmare>
AE probably got a deal on a pile of a few thousand "bad" early swim chips
<Foone>
yeah, the brochure lists a bunch of apple employees that worked on it
<Lord_Nightmare>
the pc transporter "ISM" swim chips afaik have the oldest datecodes of any known swim chips
<andlabs>
but wait
<andlabs>
who made this "pc transporter"?
<andlabs>
if it's not an official apple product
<andlabs>
and how did they get apple proprietary chips
<Lord_Nightmare>
a peripheral company called "applied engineering"
<Lord_Nightmare>
which had very close ties to apple but was an independent company
<Lord_Nightmare>
at least on paper
<andlabs>
oh
<Lord_Nightmare>
wendell sander worked at both(?) companies
<andlabs>
also what was this thing anyway
<Lord_Nightmare>
and he designed the IWM and the SWIM
<Lord_Nightmare>
for apple
<andlabs>
also cc Nerionaya for apple ii stuff
<Lord_Nightmare>
it was an 8088 pc on an apple2 card
<Lord_Nightmare>
and it used the "ISM" swim plus a program on the apple2-side for emulating a upd765
<Lord_Nightmare>
for floppy access
<Lord_Nightmare>
it had its own pc-style(?) floppy port
<Lord_Nightmare>
MAME currently cheats and puts a REAL upd765 in the 8088 address space
<Lord_Nightmare>
but the real pc transporter afaik used software on the appleIIe 65c02 and that SWIM for floppy access
<andlabs>
and when was it released?
<Lord_Nightmare>
1987 i think
<andlabs>
ah
<andlabs>
so after the SWIM
<andlabs>
eh
<Lord_Nightmare>
apple shipped the first actual SWIM chips with the mac II FDHD and mac SE FDHD in early 1988
<andlabs>
wait
<andlabs>
then what did the original Mac and Plus use
<Lord_Nightmare>
IWM
<Lord_Nightmare>
which only does GCR
<Lord_Nightmare>
no MFM
<andlabs>
ah
<Lord_Nightmare>
SWIM does both
<andlabs>
and this also is after the first PC expansions for other computers so eh
<andlabs>
I have a copy of this hilarious thing for Amiga
<andlabs>
When Commodore introduced the Amiga 1000 in July 1985 it also unexpectedly announced a software-based IBM PC emulator for it. The company demonstrated the emulator by booting IBM PC DOS and running Lotus 1-2-3.[1] Some who attended the demonstration were skeptical that the emulator, while impressive technically, could run with acceptable performance.[2] The application, called Transformer, was indeed extremely slow; The
<andlabs>
'Landmark' benchmark rated it as a 300 kHz 286, far slower than the 4.7 MHz of IBM's oldest and slowest PC. In addition, it would only run on Amigas using the 68000 microprocessor, and would not run if the Amiga had more than 512K of RAM.
<Lord_Nightmare>
bleh, buggy POS
<andlabs>
my favorite part is the last sentence
<andlabs>
because that means you can't make it fast even if you wanted to
<andlabs>
:D
<Lord_Nightmare>
hence buggy
<Lord_Nightmare>
having too much ram and it not working is a bug
<andlabs>
yes
<Lord_Nightmare>
300khz is kinda crap too, but for a flat emulator you won't get much faster without a static or dynamic recompiler
<Lord_Nightmare>
an interpreter will be slow as hell
<Foone>
yeah
<andlabs>
commodore eventually released the A1050 Sidecar which is proper hardware
<andlabs>
and then integrated the support chips directly into the motherboard in the A2000
<andlabs>
(you still needed a processor card)
<Foone>
I wrote a very limited x86 emulator in python that does full interpreting and even on modern PCs it was painfully slow
<andlabs>
nice
<Lord_Nightmare>
i think dynarec could have worked
<andlabs>
and since it's in python it's even slower than it could be
<Lord_Nightmare>
but recompiling each block would be really slow
<Lord_Nightmare>
but once compiled they should be reasonably fast
<andlabs>
qemu is still technically an emulator
<andlabs>
just...not one running on an 8Mhz 68000
<andlabs>
=P
<andlabs>
I will still try out the Transformer one day
<Lord_Nightmare>
i'm also surprised motorola was so dickish about the cost of the 68010
<andlabs>
it'll be extra fun because I won't be able to use any accelerators
<andlabs>
"HIGH END UNIX WORKSTATIONS ONLY"
<Lord_Nightmare>
had they not been so stingy aboyt 68010 cost, they could have ended up dominating the market early enough to take a chunk out of 808x
<andlabs>
"the market for the HP 9000 will never die"
<andlabs>
afk brb
<andlabs>
but yeah I do wonder what the earliest IBM PC expansion hardware for non-IBM PC computers are
<andlabs>
or even expansion software
<Lord_Nightmare>
the 68000 also has that bug where the user permissions can spy on the supervisor stack pointer
<Foone>
good question
<andlabs>
yes I know about unreleased things like the atari 1450xld
<Lord_Nightmare>
this was fixed in the 68010 and all later chips
<Lord_Nightmare>
but remains broken in *ALL* 68000 and 68HC000 etc revisions I think
<andlabs>
it would also be nice if we had a good history of early IBM PC clones
<andlabs>
or a 100% open source PC clone of any sort
<Lord_Nightmare>
i suspect fixing the 68000 microcode to fix that bug would be fairly easy, but then again i know not that much about how the 68000 microcode works
<andlabs>
(not counting the CPU of course)
<Lord_Nightmare>
Sarayan knows much more
<andlabs>
I'm going to guess they didn't want to make a breaking microarchitecture change without also changing the model number ot make it clear it was a breaking change
<andlabs>
brb
<Foone>
I seem to remember hearing that the Seattle Computer Products people made a modified version of their 8086 system that was compatible with the IBM PC, but since it was S-100 based, you could install it in a system that was technically Z80/8080 based?
<Lord_Nightmare>
true... there were the 68EC000 etc
<Lord_Nightmare>
and there's 68008 the weird 8 bit bus version
<Lord_Nightmare>
and a 68016 which is an oddball
<Lord_Nightmare>
rare
<Foone>
and there was one computer that let you install either 8080 or 8086/8088 CPU cards. That one is debatable
<Foone>
because you're not really installing a PC into a non-PC, you've just got a computer that can generically use either processor
<Foone>
given how fast things are now I wonder if you could get decent performance out of an x86-over-USB expansion card
<Foone>
I've got a couple spare FX3 dev boards maybe I should glue that to a PC/104 and see what happens
<andlabs>
back
<andlabs>
huh
<andlabs>
ok
<andlabs>
yes of course S-100 ones would be the first
<Foone>
S100 was the original personal computer standard! and it lasted a surprisingly long time
<andlabs>
there were also S-100 68000 systems
<Foone>
that was the other fun thing about S-100, yeah! even though it is traditionally 8080/z80 based, it was flexible enough that you could basically stick any random-ass CPU on there and just do some level conversion and BAM! working computer
<andlabs>
the only S-100 systems I'd actually be interested in owning are
<andlabs>
the sol-20, because it is the most aesthetic
<Foone>
I have one s-100 computer and I've never even tried to turn it on. it scares me
<andlabs>
and the vector 1, because it has the best aesthetic
<andlabs>
but I have absolutely no idea what I'd do with either and they cost too much anyway so
<andlabs>
and I don't think I'll ever port libui to one
<Foone>
the power supply is giant and ancient and scary, and I don't understand any of the S-100 cards. I am gonna have to build my own new power supply and then also do a lot of research on the cards