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11

Normally you would just let it sit for a few minutes. While the output capacitors may have some residual charge, the most any one would have is 12 Volts, which isn't really dangerous to your fingers. The input filter capacitor after the full wave rectifier, however, is a more likely threat, but killing the AC input while the power supply is under load will ...


10

Anecdotal answer, because I don't feel like googling for lots of schematics: Most AT mainboards only use +5V. In some cases, +12V is used for miscelleanous stuff, I remember an auto-voltage mainboard where the +5V/+3.45V switch for the 80486 processor used the voltage detection pin, and controlled the +5V Vcc connection using a FET that got its gate drive ...


8

A proper ISA IDE interface is quite simple, but not as easy as it might sound. There are some strange corner cases you should consider for full AT compatibility. You can find schematics for ISA IDE interface adapters in service manuals of computers slightly newer than you MFM portable computer. For example, check volume II of the Compaq Deskpro 386 technical ...


7

You can find a description of a lot of the V6366 features that actually get used in typical laptops in the Zenith TurbosPort technical reference manual. That manual clearly names the register bits that enable double-scanning (to expand the 200-line mode to your 400-line panel) and the CRTC replacement/adjustment registers needed to to adjust the timing. You ...


6

With great help by user Michael Karcher we found the following details poking through the V6366 controller's innards: # ports 102 (outside of V6366, the decoded I/O select line is called VDCS) Bit 5: 00: Plasma panel active 20: External monitor active 3d4 CRTC index port 3d5 CRTC data port (6845 compatible, except for "interlace & skew" ...


6

Looking at the three ATX PSUs I have to hand, all three of them have a bottom-mounted fan, and only one (the oldest, least efficient and noisiest) provides a -5V line. That's a Nexus NX-3500. One of the others is actually an SFX-L form factor, which mounts to an ATX case using an adapter plate which leaves a significant gap on all sides relative to a full-...


3

How to build an ATA controller for the AT bus? You can't, as there isn't any. You want to connect IDE-Drives, right? IDE stands for Integrated Device Electronics. Which simply means that the full host controller is already part of the drive. It contains everything that is on your MFM controller, except for bus-buffering, address selection and extension ROM. ...


2

Partial answer: I was unable to find [the low level programming] documentation. [...] Perhaps they can give a clue as to what ports to look for. The datasheet you linked says the V6366 is compatible to the MC6845 except interlacing and skew, and also compatible to CGA, MDA and Hercules. That already gives a good idea what the registers look like (...


2

Engineering is Driven by Specifications In general, it is always dicey to not implement the full breadth of a spec. This is engineering, not magic or wish. In the absence of other information, you must assume that all voltages in the spec are required. So to explicitly answer your question, the only sound answer is "yes", although there may be ...


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