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trag

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    Austin, TX
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    Model & Amateur Rocketry

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  1. Which part of did you guys not understand? Apology for appearing snarky. Not really intended. The specification for the 30 and 68 pin sockets is for boards with .050" thickness. Converting .050" to mm yields 1.27. Back when those SIMM sockets were current, printed circuit boards were still largely specified in inches, at least, in the USA and .050" was the specification. If you manage to look up a datasheet for the sockets, you'll find it called out there as well. Everything went to .063" sometime around when memory moved to DIMMs, w
  2. Thank you, Bolle. I thought I had read something, maybe in an Apple Tech note, about 2-chip SIMMs not being supported in the SE/30 (and others) because of some difference in refresh in X4 chips. But either I misremembered, or it was another one of those cautions that doesn't seem to apply in actual practice. Yes, in theory, you really want 1.27 mm. or .050", but it seems difficult to find. Ten years ago it was, not exactly common, but readily available.
  3. Do those 2-chip 16MB SIMMs work in the SE/30? Do you know? I laid out a board for a 2 chip 30 pin SIMM back when I was doing IIfx SIMMs, but never made any. PCB prices at the time were still prohibitive. Seed Studio and others had not yet emerged. I only made the IIfx SIMMs because one of the fabs sent me a $500-off coupon.
  4. The 4120 series is a resistive/capacitive filter, not just a pass through resistor. But Apple appears to have used a small variety of parts in this position and reportedly some of them were purely resistive. 601.pdf
  5. Seven Outbound Laptop Model 125 -- I refurbished and sold six of them and kept one, back in the mid 90s.
  6. It wasn't so much the particular brand of FPGA as that some video cards used this style of FPGA programming. FPGAs can get their configuration from a Flash or EEPROM that they read automagically, or can be configured through a JTAG or similar interface. So, normally, one might see a video card with an FPGA and an associated storage device to supply the FPGA program. FPGAs are volatile. They don't stay programmed when the power is off. But some video cards loaded the FPGA at boot time, through a driver (extension/control panel) so the FPGA code was not stored anywhere on th
  7. I bought a bunch of dual vertical 30 pin sockets from, IIRC, Jameco when they were closing them out. They are also spaced too close together, but they are relatively easy to cut apart and use individually. I use a small bench vise to hold them and a cutting wheel on a dremel to do the cutting. While a dual socket might provide some superior lateral stability, the cut-apart individual sockets do still have the strain relieving plastic pegs.
  8. 30 pin sockets either straight or angled available here: https://www.peconnectors.com/sockets-pga-cpu-and-memory/
  9. Not strictly true. The 80 pin drives are wide devices. The Mac has a narrow SCSI bus. Even though the upper (wide) bits aren't being used, they should be terminated on the drive. So just putting the drive bare in the middle of a properly terminated SCSI chain might work, but it is not proper SCSI configuration. The upper bits on the wide drive must be terminated, unless it is in the middle of a wide SCSI chain.
  10. I don't know about converting video formats but will mention that some of the video cards use Xilinx FPGAs which are configured by their driver. In other words the FPGA doesn't know what it's doing logically, until the driver loads and downloads a bit stream to the FPGA on the video card.
  11. There are black NeXT ADB mice as well...
  12. Depending on which you mean, it does some auto-detection to see what's installed. As far as whatever parameters it saves, that seems to be purely contained in the application. In theory, we should be able to hack that thing to provide support for additional drives beyond what was originally supported. I remember a message from someone who had hacked it to the extent of manually setting the configuration for his Outbound from the available choices, rather than letting the installer detect it. Unfortunately I can't remember if that was an old email, Usenet posting or other.
  13. I don't think the CF card will work but it's worth a try. The supported hard drive configurations are built into the Outbound Firmware. There's a pair of little 64Kbit Flash chips on the logic board. When one runs the software "Installer" one of the first things it does is check the configuration and flash those chips with software to support with the floppy drive or the appropriate sized hard drive. Are you old enough to remember setting cyclinder, heads, sectors (?) or something like that on PCs when installing a hard drive? It's basically that process, slightly
  14. Have you cleaned and replaced the heat sink grease on the CPU? At that age, it's probably a white crust, not doing its job any more. I have seen similar issues on 7100 machines which cleaning and replacing the CPU heat sink compound fixed. The CPU overheats very quickly without good compound. If you do replace it, be very gentle. The CPU is fragile and can be cracked with undue pressure. Also, do not overapply the replacement grease. Too much and it can run off the CPU onto the pins and cause shorts.
  15. Yeah, what Jessenator said. Ouch. Of course, until someone checks, we can hope that a smaller minimum and/or price applies. In 2011 the minimum was around 20, but that may have been a time when they had stock on hand. Now the difference could be that they're running off a new manufacturing batch every time. It's too bad The Connector People didn't have them on hand. I emailed them to check about the 8807 because they had so many of the 8817 on hand, and received a kind response very quickly that they have none of the 8807.
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