On Thu, Aug 28, 2025 at 5:51 PM Bill Gunshannon via cctalk <[email protected]> wrote: > > > I finally got the missing keyboard and now it is time to try > and revive it.
I restored one some months back. Mine is 100% IBM boards and options.... The portablePC has a normal XT motherboard in it. The standard video board is the CGA one, with the composite output (on the 4 pin connector originally designed for an RF modulator) feeding the internal amber moniitor. This is actually a Zenith unit. Note that if you want to remove or open up the monitor and PSU you need Bristol Spline tools. And tamperprrof Torx for the PSU cover. I had to take the latter apart, the mains input filter capaciitors were being antisocial and breaking down. I replaced them before they filled the worshop with magic smoke > > A couple quick questions. > > It has a board in it called IBM PC INTERFACE with the numbers > 170-18-165 and CIL18-16 printed on it. It has a 50 pin connector > on the bracket end. If I take it out the machine dies almost > immediately doing the POST. Tried Google with no luck. Anybody > remember what it is? This doesn't sound like any IBM board. Is there a maker's name on it? And how does the POST die? What error code, etc. Are there any large chips on the board, or is it all small TTL devices? > > Next problem. 1701 error. Light on MFM drive flashes 3 slow > and 4 fast continuously. Being as this machine was known to > work when it was last shut down any suggestions? Could it be > a stiction problem and the disk just isn't spinning up? (Can't > tell by listening as the fan is pretty loud. Not bad just louder > than any good disk I have ever heard.) I am pretty sure that the only official way to add a hard disk was to put it in a 5161 expansion cabinet (!) So this must be a 3rd-party devce, What is the make and model of the hard drive itself? Do you have a way of powering it up outside the machine? Just power it, with no ribbon cables connected > > And then one other not related to a problem. Being an original > PC owned by users and not geeks is it likely that the floppy > controller is one that can handle other formats (like TRS-80) > and maybe even 8"? > The original IBM floppy controller is a 3/4 length card. Theres an edge connector at the front for the ribbon cable to the internal drives and a DC37 socket on th bracket for the external drives. Mostly small ICs with one 40 pin device (NEC 765 or Intel 8272, they're essentially the same). This board is strictly double density, standard data rate only. It won't do 8" data rates. It won't do single density. > And just to wrap it up. What are the chances of finding an > external drive or even a cable that could be made to connect > to an external drive? Very easy to make the cable using an IDC DC37 plug, 34 way ribbon cable and the sockets/edge connectors to fit your drives. I am sure there are instructions on the web. -tony
