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A Blitter question...

Posted: 03 Dec 2022 18:05
by Darklord
So I've been reading this book I got off of Amazon last week, per a reference
at Atari Age. It's called "Faster Than Light: The Atari ST and the 16 Bit Revolution".

I'm about halfway through it and it's been pretty good so far.

One section did make me pause though. When the author covered the STacy,
he mentioned its blitter chip. Well, label me blind (and with some justification)
but I've never noticed a blitter chip on my STacy. I have some pictures of my
STacy's motherboard when I was doing all of those upgrades back in 2013 and
I pulled them out but was unable to find anything. So I googled the Wiki entry
for the STacy and it says it has a blitter chip.

So I fired my STacy up and there's no blitter chip entry in the drop-down menu.
Now I'm using TOS v3.06 (modified TT030 TOS) and since the TT doesn't have a
blitter chip, I figured maybe TOS v3.06 wouldn't show one, even if there. So I
ran SysInfo. It reports no blitter as well, but I'm still wondering if that's maybe
because it's reading the TOS version?

So I used the Pak 68/3's compatibility mode to boot up to a plain, 8mhz, TOS v1.4
(identical to a stock, unmodified STacy) machine. I checked the drop-down menu
again, but still no blitter entry. I ran SysInfo again, but it also (still) reports no
blitter. It's completely grayed out.

So I thought I'd run this past the knowledgeable people here. Does the STacy have
a blitter or not?

Thanks gang. :)

Re: A Blitter question...

Posted: 03 Dec 2022 18:21
by exxos
I assume pak tos disables the blitter as it can't access TTram.

It's in part why BLTFIX was developed by @agranlund to still allow the blitter to access STram but use the CPU for TTram blits.

What we need is a 32bit blitter ;)

Re: A Blitter question...

Posted: 03 Dec 2022 18:27
by stephen_usher
It's obviously a stealth, invisible Blitter. It can neither be seen visually nor using normal software. :lol:

Re: A Blitter question...

Posted: 03 Dec 2022 19:29
by DoG
I also says in the PAK manual that you should remove the blitter if you go above 32MHz. So it might have one (I have no idea) but got removed due to PAK installed on it?

EDIT: According to Atari Computer Museum it has a blitter.

Re: A Blitter question...

Posted: 03 Dec 2022 20:00
by Darklord
exxos wrote: 03 Dec 2022 18:21 I assume pak tos disables the blitter as it can't access TTram.

Its in part why BLTFIX was developed by @agranlund to still allow the blitter to access STram but use the CPU for TTram blits.

What we need is a 32bit blitter ;)
Right, I was thinking along those same lines but how to explain nothing
being shown when it's running at 8mhz and TOS v1.4? Thanks...

Oh...and you're absolutely right about the 32bit blitter. :)

Re: A Blitter question...

Posted: 03 Dec 2022 20:01
by Darklord
stephen_usher wrote: 03 Dec 2022 18:27 It's obviously a stealth, invisible Blitter. It can neither be seen visually nor using normal software. :lol:
DarkLord, using his STacy, replies:

" "

Re: A Blitter question...

Posted: 03 Dec 2022 20:02
by Darklord
DoG wrote: 03 Dec 2022 19:29 I also says in the PAK manual that you should remove the blitter if you go above 32MHz. So it might have one (I have no idea) but got removed due to PAK installed on it?

EDIT: According to Atari Computer Museum it has a blitter.
Well, in this case I was the one who installed the Pak 68/3 board. I did not remove a blitter chip
because I didn't think it had one and I've had no issues that I'm aware of. Thanks.

Re: A Blitter question...

Posted: 03 Dec 2022 21:15
by Darklord
Okay, czietz at Atari Forum posted that the Atari STacy schematics at
dev-docs does not show a blitter onboard.

Cyprian posted a couple of blitter testing apps as well. I downloaded
"blitt ST" and tried it.

Running it from C:\, under TOS v3.06 resulted in a 2 bomb error (not
fatal, it returned to the desktop).

Running it from C:\, under compatibility mode (8mhz, TOS v1.4, stock
STacy), resulted in a brief flash, with nothing else I could see, before
returning to the desktop.

Thanks.

Re: A Blitter question...

Posted: 04 Dec 2022 05:33
by derkom
The Stacy does not have a blitter chip. Never has.

Perhaps someone got confused by the shadow chip at some point?

Re: A Blitter question...

Posted: 04 Dec 2022 05:50
by Darklord
derkom wrote: 04 Dec 2022 05:33 The Stacy does not have a blitter chip. Never has.

Perhaps someone got confused by the shadow chip at some point?
That was mentioned, that some people had argued that it was
included in the Shadow chip, but others quickly pointed out that
the Shadow chip can't possibly meet the requirements.

I've run 2 blitter testing apps now and both do nothing or crash
out, which I'm told means they could not find a blitter. Add to
that the fact that it's not on the STacy schematics and I'm just
going to conclude that the online Wiki and Museums have got
it wrong, as well as the "Faster Than Light" book...

There. My regularly scheduled Saturday Atari quest is now
concluded... :)