New (luggable) laptop.

[pentium]

a local place had a "drag home what you can for free sale" and out of the half hour it took me to get this hime I am now the owner of an IBM 5155 PC portable with math co-processor.
Once it came home I swapped out a bad floppy drive and installed a nice Trantor T130B scsi card and a 40 meg ST-251N hard drive as well as replace to IO card with one that maxed the system with 640k ram and replaced the floppy controller (had trouble with room) and installed an internal 9600 Baud modem.
It's now happily running DOS 5.0 and along with other things it has windows 1.01 on it! Happy to say that this version of windows is pretty rock solid. Then again you could toss this system and kill someone given the steel reinforced handle.
I also have a nice ATI graphics card that just needs an 8-bit ISA slot but it's internal video output connector does not want to properly output a signal the screen will work with. It would be nice if I had the dipswitch settings for the card.

[linuxguru]

Re: New (luggable) laptop.

Is it an EGA/VGA Wonder or similar? I have something similar lying somewhere, which can do various special resolutions, including 640x350 mono grayscale, 640x400 mono grayscale interlaced, etc. which are useful for driving the original mono and color monitors that came with the IBM PC Model 5150. Haven't had a chance to fiddle with it for about 15 years...

[starfury1]

Re: New (luggable) laptop.

lol mine was abit more ancient then that ..it run CP/M It had 360K floppies and 128 Kb yes "K" memory

I must be getting old I actually remember this stuff when it was new

http://www.geocities.com/homeofoscar...uters.html#CPM

[acstech]

Re: New (luggable) laptop.

Looks like 4 grayscale CGA to me, on the screen anyway.

Those were the days...

Find any bad caps?

[pentium]

Re: New (luggable) laptop.

Well besides some very annoying tamper-proof screws holding the PSU closed I managed to look in there and find no badcaps but I suspect one or two are going south around the CRT as the brightness will change over time and also the picture will begin to drift to the left.
Well before I got my hands on this it only had 256k ram. Even with DOS 5 it still has over 450-500k free. To my knowledge the screen is monocrome (I don't know if it's MGA, EGA etc.) and has no burn-in.

[linuxguru]

Re: New (luggable) laptop.

AFAIK, it's monochrome, but uses CGA resolution and sync frequencies. It can't be driven by an MDA or Hercules MGA card - which do 720x350 at a higher sync frequency of around 18khz+, but it can probably be driven by an 8-bit ISA ATI EGA Wonder, which does interlaced 640x350 EGA 16-colour or 16-grayscale on a CGA monitor. The tricky part is finding the DIP switch settings for monitor/resolution combinations on the Wonder - it's usually set by default to EGA/640x350 non-interlaced.

http://www.vintage-computer.com/ibmportable.shtml

I built a cacheless upgrade card in 1990 that used a 80286/8 MHz with bus-converter logic in 5 PALs to replace an 8088 using the same 40 pins, to which it connected with a 40-pin ribbon cable and DIP connector. It came to market *way* too late for it to be viable, and also prompted my career switch to software. Victor Technologies (of Victor 9000 fame) also built a similar upgrade card (8088->80286) for a while - I have one of those in my vintage parts collection, as well.

The best of that lot of upgrade cards was probably an Orchid Tiny Turbo 286, which has 16-bit SRAM cache and can upgrade an 8088 box to fairly respectable processor speeds - good enough to run a current version of FreeDOS or an older version of Minix at comfortable speeds. FreeDOS + GEM is a usable combo, even today.

Another option is to try to replace the mobo lock,stock and barrel with a Baby AT form-factor mobo - this will allow P3/Athlon class mobos to be fitted there. But you'll need an ISA slot for the EGA Wonder, which limits the available mobo choices a bit - the Biostar M6VLA or similar S370 boards come to mind. You'll also need to upgrade the PSU/PSU connector, and several other things - including fitting an IDE 3.5" drive in a 5.25" tray.

Yet another option is to use an XT form-factor upgrade mobo with an 286 CPU - there was one called the Bullet 286 XT, which had a full set of 7/8 8-bit XT slots, but used an 80286/287 CPU/NPU combo. This will even run the original IBM PC ROM Basic, but it has to be burned into larger-sized EPROMs and split into High- and Low-byte pairs.

[pentium]

Re: New (luggable) laptop.

Well for now I will leave it as it is. I only have one ISA slot left and I really don't want to tear this system apart again to install a newer board. This 8088 is running fine.