Running a ROM on an everdrive is one thing, but running a ROM
directly is another: my hacked up sega.bin didn't have a proper
checksum, so the ROM didn't run.

This new tool transforms a binary into a properly-headered ROM.

Has been tested on an actual SMS.

The PAD driver was broken since IP moved to BC. Oops.

also, verify all 3 first bytes of SPI commands. I'm not sure why
I wasn't doing that, probably because I was getting a lot of AVR
err and thought that only 2 bytes of the cmd were echoed. But now,
with a reliable SPI setup, verifying 3 bytes seems to work.

After many trials and errors in reliably accessing AVR chips through
my SPI relay design, I resigned myself to accepting 125kHz communication
speed with it. I find the complexity of solutions allowing to keep 250kHz
speeds to be excessive.

Also, remove needless argtype in CALL and RET

Adding a delay such as the 20ms one we have in AVR programmer's
initialization routine is tricky without a word like TICKS.

This implementation is highly inaccurate, but more accurate and
reliable than a "ballpark" DO..LOOP...

Very very simplistic, but works with our driver.

ABORT" doesn't work in xcomp.

Also, improve xcomp docs and fix misdocumentation.

That slims down blkfs a lot.

Also, remove leftovers from previous move.

And move its doc to doc/asm.txt

Also, move doc to doc/asm.txt.

Also, fix the pcat recipe which was broken since the overlay change.
I hadn't noticed it because I didn't have to rebuild the MBR.

The idea is to consider assemblers as "runtime" apps instead of
placing them in the "bootstrap" section of the blocks. These apps
will be used for much more than bootstrapping.

Moved its documentation to doc/asm.txt and made its code blocks
more compact.

The few extra bytes they save in the core aren't worth the extra
complexity. This was initially done in a context where I had
troubles keeping the RC2014 binary with SDC inside the 8K limit.

At this point, even with the few extra bytes we add here, we're at
7200 bytes, so I'd say we're fine.

With the Visual Editor, BROWSE is of dubious value. Even before that,
it was of dubious value. It's the only user of the CASE word, which
is also of dubious value: too complicated for its own good.

The CMD pattern used in VE is much better.

Their asm code has been broken for a little while! oops!

This marks the end of wordrefs in stable ABI. Nice.

The ":" now takes care of scanning for ";". Conceptually, having
";" as an immediate word is slightly simpler than the approach in
this commit, but when bootstrapping is involved, this simpler
approach gets murkier.

Moreover, it got even murkier-er when trying to de-stabilize EXIT,
so here we are.

This duplicated feature existed because of bootstrapping issues
with LIT", but again, with careful threading, we can clean things
up.

We can now have a proper "Collapse OS" prompt :)

I've mistakenly broken it in previous commit.

When writing the xcomp documentation, I realized that with careful
threading and by accepting a bit of code duplication in the xcomp
toolset, I could de-stabilize a couple of words.

(n) and EXIT are a bit trickier, but I think it can be done. It
would be nice to get rid of stable wordrefs...

Also, fix the SPI relay driver to properly AND-away the result of
the CTL read.

Tested with a real prototype, works fine.

By default, it changes nothing, but it allows interesting
setups, such as using AT28! for directly uploading to EEPROM.

I've also updated the EEPROM recipe to upload directly to 0x2000.
I'm not sure what has changed, but it's working fine now.

Previously, communications with my RC2014 would always be rocky and
fail most of the time. By sending an CR at init, things go much
smoother.

Working on programming AVR chips exposes a glaring omission in my
first design of the SPI Relay: not allowing multiple devices make
this task hard. I constantly have to unplug my SD card before, plug
the AVR chip holder, then play a bit, then unplug the AVR holder,
then replug the SD card...

My prototype for a SPI relay design is built, but I haven't tested
it yet. I need to adapt the code first, which is what I do here.

When the prototype is tested, I'll update the SDC recipe with a new
schema.

The batch mode thing seems to have been caused by bad timing on my
prototype. Now that I've corrected it, live interaction seems to
work fine.

After having done my initial handshaking, I thought the rest of the
job was only a matter of implementing the protocol, but I was wrong.
There were many issues to fix before I could reliably communicate
with my 328P, mostly timing.

Now, I seem to be able to reliably extract fuse information, but
only in batch mode (that is, run "asp$ aspfl@" directly, then
running "(spid)" before running the next command). If I try to
interact with the chip in a single asp$ session, I sometimes get
wrong values (but no sync error! that's worrying...).

chkPS, used to be only for words that pushed back to PS, but I've
recently removed underflow checks from next and I forgot to add
missing chkPS, calls that go with this change.

AVR chips often run at less than z80's system clock. This means that
our SPI relay needs to have its own clock to properly communicate
with it. This means that the delay between OUT and IN can't be
hardcoded to 2 NOPs anymore. It needs to be configurable.