26 Oct
2015
26 Oct
'15
8:30 p.m.
Can anyone confirm whether a Mac IIsi spits out sync-on-green (and only
sync-on-green) or not? I've found mixed info on the 'net so far.
I've got a system here which makes encouraging startup noises, but isn't
outputting any video to a VGA screen (adapter cable OK with my other Macs).
If it's SoG-only, well, there's my problem :-) If it does output h/vsync
like my other Macs then I need to look elsewhere (most likely nonsense
NVRAM settings, I expect).
cheers
Jules
26 Oct
26 Oct
10:54 p.m.
AFAIK there's nothing special about the video on the IIsi ... pretty sure
that if the adapter and monitor will work with i.e. a standard Mac II
640x480x8 NuBus board (or equivalent) it should work with the IIsi.
Best,
Sean
On Mon, Oct 26, 2015 at 11:30 PM, Jules Richardson <
jules.richardson99 at gmail.com> wrote:
Can anyone confirm whether a Mac IIsi spits out sync-on-green (and only
sync-on-green) or not? I've found mixed info on the 'net so far.
I've got a system here which makes encouraging startup noises, but isn't
outputting any video to a VGA screen (adapter cable OK with my other Macs).
If it's SoG-only, well, there's my problem :-) If it does output h/vsync
like my other Macs then I need to look elsewhere (most likely nonsense
NVRAM settings, I expect).
cheers
Jules
27 Oct
27 Oct
1:05 a.m.
New subject: Caps. Was: Mac IIsi - SoG?
did you replace the caps on the motherboard. those machines are in the
suspect zone, like the IIci, IIcx and the like. On most of them the
aluminium caps have gone bad and are leaking on the board, inflicting
all kinds of damage.
simon
On 27-10-15 06:54, Sean Caron wrote:
AFAIK there's nothing special about the video on
the IIsi ... pretty sure
that if the adapter and monitor will work with i.e. a standard Mac II
640x480x8 NuBus board (or equivalent) it should work with the IIsi.
Best,
Sean
On Mon, Oct 26, 2015 at 11:30 PM, Jules Richardson <
jules.richardson99 at gmail.com> wrote:
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
Can anyone confirm whether a Mac IIsi spits out sync-on-green (and only
sync-on-green) or not? I've found mixed info on the 'net so far.
I've got a system here which makes encouraging startup noises, but isn't
outputting any video to a VGA screen (adapter cable OK with my other Macs).
If it's SoG-only, well, there's my problem :-) If it does output h/vsync
like my other Macs then I need to look elsewhere (most likely nonsense
NVRAM settings, I expect).
cheers
Jules
4:42 p.m.
On 10/27/2015 12:54 AM, Sean Caron wrote:
AFAIK there's nothing special about the video on
the IIsi ... pretty sure
that if the adapter and monitor will work with i.e. a standard Mac II
640x480x8 NuBus board (or equivalent) it should work with the IIsi.
Hmm, looks like this one has issues, then. I don't have an operational
'scope here, but I did set my meter to the frequency range and put it on
both the hsync and the green video line, but it didn't read anything - I'd
expect to see something in the tens of KHz range on one or the other.
I pulled the NVRAM battery (it was completely dead) and for now have
replaced with a 3V pack consisting of two AA cells - I would expect that to
be enough (compared to the correct 3.6V battery), but I suppose it's
possible that it's not. Anyway, I did the command-option-P-R sequence to
reset the NVRAM at startup (and got the second chime to suggest that it had
done the reset), but unfortunately no dice.
The board caps are visually good - i.e. no obvious leaking/corrosion.
All the board fuses check out OK (quite probably not related to the video
circuits anyway)
+5V and +12V are OK; I've not located a good/simple spot to check for -12V yet.
I noticed that there's no W1 jumper fitted. According to section 2.5.7 at
http://macfaq.org/hardware/logicboard.shtml there should be if the board is
running from the on-board ROMs rather than a ROM SIMM - but if I fit that
jumper then I no longer get the startup chime; can anyone confirm that
macfaq is correct and I'm supposed to have the jumper fitted if the machine
*doesn't* have the SIMM?
One final note: the system has a Carrera '040 board fitted in the
accelerator slot. The working state of that board is unknown (just like the
rest of the machine) - if I remove it for now, do I need to change any
jumpers or anything on the main system board so that the on-board '030 will
act as primary CPU, or should that happen automatically?
I wish I knew at what point the chimes are generated - I don't know if it's
just some lowly service processor which produces those, or if it implies
that basic ROM, RAM, CPU etc. are all OK for it to ever get that far
(talking of which, I haven't tried swapping RAM; I suppose it might be
faulty in such a way that it's knocking the video out entirely).
cheers
Jules
6:32 p.m.
On 10/27/2015 07:27 PM, Al Kossow wrote:
On 10/27/15 4:42 PM, Jules Richardson wrote:
Thanks, Al. I'm reasonably confident that it's alive and well, then, but
with no video output. Who knows, maybe someone plugged a PC joystick into
the video connector, or something :/
Still a bit odd how the presence of the W1 jumper appears to hang the
machine though.
cheers
Jules
I don't know if
it's just some lowly service processor
nope, just the 68030.
6:03 p.m.
Try pulling the accelerator board out of the PDS slot ... I've seen a lot
of accelerator boards go bad over time but when removed, the underlying Mac
is actually okay ... You should just be able to yank the board; it's all
plug-n-play for the most part.
There should be Macintosh ROMs on the motherboard; look for a few
20-some-odd-pin DIL packages with (C) APPLE on them ... I believe the ROM
SIMM slot is just there for upgrade potential (never utilized).
No service processors or anything here; the CPU on the logic board (or on
the accelerator board) does it all.
If you're getting a startup chime, that implies the battery is providing
sufficient "juice" (or the logic board doesn't care that much) to power on;
the PSU is providing nominally sane voltages to the logic and it's managing
to execute at least a little bit of the ROM ...
Best,
Sean
On Tue, Oct 27, 2015 at 7:42 PM, Jules Richardson <
jules.richardson99 at gmail.com> wrote:
On 10/27/2015 12:54 AM, Sean Caron wrote:
AFAIK there's nothing special about the video
on the IIsi ... pretty sure
that if the adapter and monitor will work with i.e. a standard Mac II
640x480x8 NuBus board (or equivalent) it should work with the IIsi.
Hmm, looks like this one has issues, then. I don't have an operational
'scope here, but I did set my meter to the frequency range and put it on
both the hsync and the green video line, but it didn't read anything - I'd
expect to see something in the tens of KHz range on one or the other.
I pulled the NVRAM battery (it was completely dead) and for now have
replaced with a 3V pack consisting of two AA cells - I would expect that to
be enough (compared to the correct 3.6V battery), but I suppose it's
possible that it's not. Anyway, I did the command-option-P-R sequence to
reset the NVRAM at startup (and got the second chime to suggest that it had
done the reset), but unfortunately no dice.
The board caps are visually good - i.e. no obvious leaking/corrosion.
All the board fuses check out OK (quite probably not related to the video
circuits anyway)
+5V and +12V are OK; I've not located a good/simple spot to check for -12V
yet.
I noticed that there's no W1 jumper fitted. According to section 2.5.7 at
http://macfaq.org/hardware/logicboard.shtml there should be if the board
is running from the on-board ROMs rather than a ROM SIMM - but if I fit
that jumper then I no longer get the startup chime; can anyone confirm that
macfaq is correct and I'm supposed to have the jumper fitted if the machine
*doesn't* have the SIMM?
One final note: the system has a Carrera '040 board fitted in the
accelerator slot. The working state of that board is unknown (just like the
rest of the machine) - if I remove it for now, do I need to change any
jumpers or anything on the main system board so that the on-board '030 will
act as primary CPU, or should that happen automatically?
I wish I knew at what point the chimes are generated - I don't know if
it's just some lowly service processor which produces those, or if it
implies that basic ROM, RAM, CPU etc. are all OK for it to ever get that
far (talking of which, I haven't tried swapping RAM; I suppose it might be
faulty in such a way that it's knocking the video out entirely).
cheers
Jules
7:10 p.m.
On 10/27/2015 08:36 PM, Al Kossow wrote:
On 10/26/15 8:30 PM, Jules Richardson wrote:
Hmm, so strapping pin 7 to pin 10 on the video connector isn't enough to
kick it into 640x480 mode like it is with various other Apple hardware?
For the 512x384 mode it's certainly not within VGA spec, but I know the
system is capable of 640x480, which I'm assuming should be. I'm currently
wondering if it's outputting composite sync, though - everything I'd seen
suggested it was either SoG or separate h/vsync, but maybe that's wrong and
it's neither.
cheers
J.
I've got a system here which makes
encouraging startup noises, but isn't
outputting any video to a VGA screen (adapter cable OK with my other Macs).
The si and cx/ci are old enough that it doesn't support VGA timing. 
7:18 p.m.
On 10/27/15 7:10 PM, Jules Richardson wrote:
On 10/27/2015 08:36 PM, Al Kossow wrote:
here is a mirror of the tech note that describes the pinouts and sense codes
https://web.archive.org/web/20040222182709/http://developer.apple.com/techn…
The RBV ASIC in the SI only knows about the original 8 sense codes.
On 10/26/15 8:30 PM, Jules Richardson wrote:
Hmm, so strapping pin 7 to pin 10 on the video connector isn't enough to kick it into
640x480 mode like it is with various other Apple hardware?
For the 512x384 mode it's certainly not within VGA spec, but I know the system is
capable of 640x480, which I'm assuming should be. I'm currently wondering if
it's outputting composite sync, though -
everything I'd seen suggested it was either SoG or separate h/vsync, but maybe
that's wrong and it's neither.
cheers
J.
I've got a system here which makes
encouraging startup noises, but isn't
outputting any video to a VGA screen (adapter cable OK with my other Macs).
The si and cx/ci are old enough that it doesn't support VGA timing.
7:30 p.m.
On 10/27/2015 09:18 PM, Al Kossow wrote:
here is a mirror of the tech note that describes the
pinouts and sense codes
https://web.archive.org/web/20040222182709/http://developer.apple.com/techn…
The RBV ASIC in the SI only knows about the original 8 sense codes.
I just got it running a minute ago! I found a note on Herb's
retrotechnology site:
"The newer Macintosh II Video Cards and Macintosh IIci built-in video
require that pin 4 (SENSE0) be connected to Ground to signal the connection
of a 640 x 480 monitor. Do not connect pins 7 or 10 as they are unused on
original Macintosh II Video Cards and there are built-in pullup resistors
on the newer Macintosh II Video Card and Macintosh IIci to terminate these
pins when not in use."
... and leaving 7 & 10 nc, and grounding pin 4 has indeed kicked it into
life (currently running on an ELO touchscreen LCD, it remains to be seen
whether any of my other LCDs or CRTs have problems with it)
cheers!
Jules
3343
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10 comments
4 participants
participants (4)
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aek＠bitsavers.org -
jules.richardson99＠gmail.com -
scaron＠umich.edu -
simski＠dds.nl