July 18, 2019, 02:46:55 am

Recent posts

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Classic Computer Marketplace / Re: brand new NeXT Cube (germa...
Last post by Andreas - July 17, 2019, 08:40:19 am
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Black Hardware / Re: NeXTStation raising except...
Last post by barcher174 - July 17, 2019, 06:25:57 am
The resistor is normal. That blob of solder next to it is not. You should clean that up. Is your Cpu soldered down or socketed?  Those possibly shorted pins are concerning.
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Black Hardware / Re: NeXTStation raising except...
Last post by m18e - July 17, 2019, 05:17:22 am
Two of the 74F543's (U14, U23) do seem to be running hotter than the others. Not hot enough to scald but definitely uncomfortable to touch.

Hardware's not my forte; what else should I be looking at as a consequence of the hotter than normal latches? Broken solder joints?

One thing I did notice when I had the motherboard out tonight is that there's something (capacitor?) soldered across a couple CPU pins on the backside of the motherboard... here's a picture: https://i.imgur.com/Z7MUgzb.jpg

Is that normal?

(I straightened out the pins in the top left so they wouldn't come close to touching)
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NEXTSTEP / OPENSTEP Software / SunSoft WorkShop, which of the...
Last post by shogo2040 - July 17, 2019, 02:43:07 am
Which version of Sun Workshop includes the Solaris OpenStep Development Environment?  I am thinking its Sun Workshop 3.0 based on the 1997 year listed on this Wikipedia page:

https://en.wikipedia.org/wiki/Oracle_Developer_Studio#History

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The Lounge / NeXT Software and Peripherals ...
Last post by neozeed - July 16, 2019, 12:46:21 pm
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Black Hardware / Re: NeXTStation raising except...
Last post by barcher174 - July 16, 2019, 04:17:50 am
Mine is working. I think in the end it's a different error though. I had an exception #4 which I confused with your error #3. For me the issue was a shorted pin on the ASIC controlling the SCSI controller which was only visible under a scope. I bent it back and reflowed with success. Here's what I would try in your case:

There's an exceptions section of the 68040 user guide:
https://www.nxp.com/docs/en/reference-manual/MC68040UM.pdf
You want Table 8-1. Exception Vector Assignments

From this we see that the vector number and code match to the table. So it looks like NeXT used this table directly which is good news going forward. The description says:

8.2.2 Address Error Exception
An address error exception occurs when the processor attempts to prefetch an instruction
from an odd address. This includes the case of a conditional branch instruction with an
odd branch offset that is not taken. A prefetch bus cycle is not executed, and the
processor begins exception processing after the currently executing instructions have
completed. If the completion of these instructions generates another exception, the
address error exception is deferred, and the new exception is serviced. After exception
processing for the address error exception commences, the sequence is the same as an
access fault exception, except that the vector number is 3 and the vector offset in the
stack frame refers to the address error vector. The stack frame is generated containing
the address of the instruction that caused the address error and the address itself (A0 is
cleared). If an address error occurs during the exception processing for a bus error,
address error, or reset, a double bus fault occurs.

Looking at the schematic here:
http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/Schematics/Turbo_slab/CSlab33-04.pdf

The 7F543s look like a good place to start. Check for any really hot ones.

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Black Hardware / Re: NeXTStation raising except...
Last post by m18e - July 16, 2019, 03:49:18 am
Good to hear! (Well, not really :) ) Hopefully we can get these problems licked; I'm really missing playing around on my slab!
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Black Hardware / Re: NeXTStation raising except...
Last post by barcher174 - July 15, 2019, 06:04:48 am
It seems I have a mono turbo station with the same problem. Recapped, drive swaps, RAM swaps, and cable swaps with no success. I'm convinced there's a board level fault. I'll let you know what I find. The SCSI portion is identical between the color and mono systems.
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NeXT Work Logs / Re: NeXTstation Color web serv...
Last post by barcher174 - July 15, 2019, 03:21:24 am
Cool to see original hardware doing something!  If you want to run continuously I would suggest an ATX modification instead of a recap. Firstly because a recap of the station power supplies is a nightmare and secondly because a new power supply is likely both safer and much more energy efficient. 
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