PenMaster Launching Windows for Pen Computing
As has been the case with other participants my Retrochallenge has been somewhat blown off course by outside events. Still I had some initial fun tinkering with the Samsung PenMaster. Although it didn’t provide much of a challenge it was interesting to look back at the false start tablet computing had with pen based computing.
IBM 5140 Convertible
I then moved on to the IBM 5140 which is a machine I really enjoyed using. Its slightly absurd design with its expansion ‘slices’ leading to an ever-increasing footprint is tempered by its overall solidity and great keyboard. I would very much like to obtain an original monitor and I noticed today someone is selling new in the box printer units for it.
ADC 212 Internals
Arriving too late in the day for me to get my teeth into it was an Anderson Jacobson ADC 212 acoustic coupler. I had hoped to use it to connect to either mine or Urbancamo’s new BBS but time has run out. Getting the coupler working may form the basis of my next challenge.
I’m now looking forward to catching up on the other participant’s entries, some of which are clearly very impressive.
Hooked Up To An IIyama LCD
The non backlit LCD display on the 5140 is poor to say the least, low contrast and dim. Fortunately I have the expansion ‘slice’ that offers CGA and composite outputs, unfortunately it smoked alarmingly the first time I powered it up. However after taking it apart and not being able to find any obvious damage I decided to risk it and plug it in again. I don’t think I’ve got any monitors capable of hooking up to the CGA output so I decided to try the composite out. I wasn’t expecting it to work but was pleasantly surprised when my trusty IIyama flat panel picked up a signal.
Initially it looked pretty awful, all sorts of convergence issues and generally pretty fuzzy. The IIyama however offers a lot of adjustment options and after fiddling with the brightness and contrast, reducing the colour to zero and altering the sharpness I had a pretty useable image. I then remembered you can alter the output via the Application Selector supplied with PC-DOS. Sure enough once I’d changed it from colour to mono I was pleasantly surprised by the quality of the composite output. After a bit more fiddling I was even able to achieve a cool retro amber look by altering the colour temperature.
I’ve been trying out the expansion units that came with the 5140 and clip on to the back of the main machine. One provides parallel and serial ports and the other is for connecting a monitor. Unfortunately I had a ‘magic smoke’ incident with the later unit after powering up the machine. It was a bit of an ‘oh shit’ moment as initially I didn’t notice it but caught a whiff of the tell tale stench before spotting the smoke rising from the unit and shutting it down. I haven’t opened it up yet to see what the damage is but hopefully it’s repairable.
Expansion Bus Connector
The expansion bus on the 5140 uses 8-bit ISA architecture. At the rear of the unit is a single 72 pin edge connector which is repeated on the back of each expansion unit. Once attached the expansion units give the machine a very odd look, especially if you also attach the printer unit which results in the 5140 almost doubling in length.
Theoretically you could create some kind of hack with an old unit and hook up an HDD but that’s well beyond my level of tinkering.
Serial/Parallel Expansion Unit
The serial port on the interface expansion unit is working. I downloaded the ever dependable Kermit and after stripping it somewhat to fit onto a 720k floppy loaded it up and dialled out to my BBS and sent off a couple of emails. It’s been interesting running a machine with no fixed disk. The second drive by the way has started working, maybe whatever was preventing it from reading disks before has been dislodged. I made a quick video of the 5140 below:-
I also found the following advert for the 5140 on Youtube, in it you can see the machine hooked up to a monitor, I lust after that monitor, I want one, a lot:-