2017年11月14日 · I'm looking for two things: 1) Someone who has experience in troubleshooting dead 386/486/socket7 motherboards with an oscilloscope and is willing to share their knowledge. 2) An all inclusive hand holding self-help guide to troubleshooting dead 386/486 motherboards with an oscilloscope. My situation is as follows: I have four MSI MS-3131 ...

2020年4月24日 · Re: Pine Technology 486 Board CMOS Issues / Chip Identification « Reply #1 on: April 27, 2020, 09:24:47 pm » Quote from: SilverTailJay on April 24, 2020, 12:16:42 pm

2013年8月15日 · The main processor board is a 486/DX2-66 Multibus 1 board with eprom and ram - no NVRAM. The next board has 8 NVRAM chips, all soldered. There are two RF boards that also look like they're on the bus. One of them has a soldered NVRAM chip. On bootup, the processor board hangs with a diagnostic light that signifies a Multibus timeout.

2017年11月19日 · power on, PG starts low -> 6 of 4069 High -> 4 of 4069 Low -> 12 of 74LS14 High -> 8 of 74LS32 High -> RESET is active, system is stopped. power stabilizes, PG goes High -> 6 of 4069 Low -> 4 of 4069 still pulled Low while capacitor is charging -> 12 of 74LS14 High -> 8 of 74LS32 High -> RESET is active, system is stopped.

2014年8月12日 · 486 boards typically came with 25, 33, 40, or 50MHz clocks. 90% used 25 and 33 with a clock multiplier in the chip, data ran externally at the clock speed of board but internally at a multiple. There was a 486 DX50 that ran at full speed internally and externally but it was rather expensive. I think AMD or Cyrix may have made a 40MHz clocked cpu.

2020年12月12日 · Re: Vintage CD player repair : Philips CDC 486 6 disc changer. « Reply #24 on: December 14, 2020, 02:29:41 pm » Definitely replace that 33uF first though, before touching the laser current adjustment - it has a direct influence on the stability of the current control loop.

2017年3月27日 · Ha. So I bought this system new in 1993. My plan was to rebuild the 486 as it had been plucked of drives and other components, handed down to a sibling in 1996, and then placed in the attic/storage for a couple of decades. I didn't think I would be combining my electronics hobby with my vintage computing hobby, but the battery took its toll.

2021年7月20日 · Check out the Saelig newsletter about fake chips. [email protected] Fake chips are a serious concern for military and other critical systems, so DARPA created a program ~8 years to help identify a legit chip. The idea was to have a tiny, ~ $0.01 RFID tag chip embedded in the package.

2018年2月11日 · Hi! I have a 486DX 33 computer bought in 1990 and still used. The hard drive packed it in, a 2.5 gig MAXTOR IDE HD, I haven't played around with this computer in a long time (using it for CAD work ).

2022年7月11日 · - Z80 was the precursor of 8086, 80186, 286, 386, 486, etc. ... my Vt100 terminal has a z80 chip inside. ...