Awesome! Congrats to everyone involved! Marc
> On Mar 28, 2022, at 12:24 PM, js--- via cctalk <cctalk@classiccmp.org> wrote: > > >> On 2022-02-25 16:09, js--- via cctalk wrote: >> >> Hi, folks. >> >> I've a HP 9915A computer with an interesting problem. The motherboard >> utilizes a ceramic Intel D8048 chip. The problem is that this 8048 has a >> crack right across the top middle of it, and half of the top of the chip has >> begun to separate. >> >> Powering up the machine as-is unsurprisingly results in no activity. >> HOWEVER, if I push firmly on the cracked area with my finger the machine >> starts to operate normally. All appearances are that clamping down the >> separating piece of the chip re-establishes any broken wire connections >> within the chip. >> >> I've obtained a replacement P8048AH. My question is: do these chips >> simply swap like a CPU, or -- as I fear -- is the 8048 a pre-programmed >> piece? More simply put, is this a repairable problem? Or am I SOL? >> >> Any thoughts welcomed. >> >> - John Singleton >> > > > Hi, folks. With the help of the extremely talented people here, the far > less talented me was able to repair this seemingly impossible problem and get > the 9915 functional. > > The process was to: > > 1) burn a new 8748 CPU with the 9915's 8048 ROM code. > I used a Data I/O 2900 for this purpose. > > 2) remove the remnants of the original 8048 CPU > > 3) install a new milled 40 pin socket > > 4) install the 8748 into that socket and power-on test. > > > Thanks to Paul Berger, Will Cooke, and Wayne S for their useful suggestions. > > A very special thanks to Tony Duell for offering to go to great lengths to > help. > > A very, very special thanks to Dave McGuire for having done all the hard work > in retrieving the 8048's code to begin with (which he had done already for > someone else), then providing the 8048 ROM code to me in hex format, plus > guidance on how to fix the problem all the way through. > > - John S.
