I got this one from IBM, I used to work there just after they stopped selling them. It's pretty close to original stock including an IBM 256KB RAM card what could go in a short slot. IBM had a number of cards then that fit in the shorter slots. https://www.vintagecomputer.net/ibm/5155/
Bill On Thu, Aug 28, 2025 at 3:51 PM Tony Duell via cctalk <[email protected]> wrote: > On Thu, Aug 28, 2025 at 7:46 PM Bill Gunshannon via cctalk > <[email protected]> wrote: > > > > > > > > On 8/28/2025 1:07 PM, Tony Duell wrote: > > > 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. > > > > That explains the weird little cable stretching over some of the boards > > and getting in the way. :-) > > It's normally yellow and black twisted pair. > > As standard, the CGA card goes in slot 1, closest to the PSU. Floppy > controller in slot 3. This leaves slot 2 as an empty full-length slot > and slots 4-7 as half-length ones. Slot 8 is not really useable. Being > an XT motherboard, the card there has to assert the buffer enable pin > on reads. The only IBM card that will do that is the async serial one. > And it's about 1/4" too long to fit, it fouls the power connectors on > the drives. > > > > > > > > > > Note that if you want to remove or open up the monitor and PSU you > > > need Bristol Spline tools. > > > > Does it make me a true geek if I say that I actually have a set of them? > > > > > 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 > > > > PSU seems fine. > > > > > > > > > > And how does the POST die? What error code, etc. > > > > Well, lets confuse things even more. Took th3e card out again and > > the system tested all 640K and went into BASIC. > > Which is what you'd expect with no bootable disk in the system. > > > > > What is the make and model of the hard drive itself? > > > > No idea yet as it is buried in the system below the floppy. But I > > plan on pulling it out as soon as I figure out the mounting scheme > > for the disks. > > I seem to remember you need a 5.5mm or 7/32" spanner and nutdriver to > do that. You take off the earthing bracket on the right hand side of > the drives towards the rear, then loose the other 3 screws on each > drive and slide them out backwards. > > There are some useful manuals on bitsavers. The Technical Reference > for the PC/XT and portablePC gives the motherboard schematic and BIOS > source. The Options and Adapters volume 1 gives the schemaitcs for the > drives and monitor. And volume 2 gives the CGA and floppy controller > schematics (and lots of others). > > Finally there's the Hardware Maintenance and Service manual for the > portablePC. This is a 'boardswaper guide' but it tells you what to > unplug and what to unscrew to get things out. > > -tony >
