When you have been round for the early days of the private pc revolution, you’ll little question recall the thrill each time IBM introduced a brand new model of its beige packing containers. For lots of us, the thrill was purely vicarious, for regardless of the “private” moniker, mere mortals might hardly ever afford a branded IBM machine. However it was nonetheless cool to maintain observe of the most recent releases, and dream of the times when low cost clones would make it doable to play.
[Anders Nielsen]’s current discover of an authentic IBM Mannequin 5160 motherboard type of echoes that long-ago pleasure, however differently. This board, from a PC XT in-built 1984, was in unknown situation upon arrival, so [Anders] set a couple of cautious course of to attempt to carry the board again to life. A fast visible inspection leaves one with a way of each how a lot issues have modified, and the way a lot they’ve stayed the identical. Apart from the large 40-pin DIP 8088 CPU and the BIOS ROMs, the board is nearly utterly populated with discrete logic chips, however on the identical time, the essential footprint of a motherboard has modified little or no.
The bring-up course of within the video beneath consists of checks of all the ability rails for shorts, which ended up being a superb name — drat these tantalums. After fixing that challenge, [Anders] had a little bit of bother getting the board to POST, and ultimately resorted to dumping the BIOS ROMs and inspecting the contents. One of many chips had picked up a case of the scramblies sooner or later, which was straightforward sufficient to repair thanks to photographs of the 5160 ROMs obtainable on-line. We thought the trick of utilizing a 64k ROM and simply writing the BIOS picture twice was fairly intelligent.
In the long run, the board got here up, though with out video or keyboard — that’s for one more day. Can’t discover your personal PC XT motherboard to play with? Then possibly you may simply construct one.
