IBM PC Parts

[Great Hierophant]

There is such a thing as a perfect IBM PC 5150, just that you can't really use it all at once (except in one instance).

My vision of the perfect IBM PC uses only IBM parts unless otherwise non-existent. It embodies the height of compatibility and functionality. However, I would stress that it is not an earliest IBM PC, nor is it the most treked out IBM PC you could ever buy.

The IBM PC Model 5150 has five expansion slots (8-bit ISA), a co-processor (8087) socket and two full height drive bays. IBM's maximum configuration put two full-height 5.25" floppy ("diskette") drives in those bays, filling them up (and the Adapter for them). The power supply IBM used, a 63.5W box, could not support the large drives that were used back in the day. Obviously, that 8087 coprocessor socket should be filled with an 8087, which IBM did offer as an option.

The motherboard should be 64/256K motherboard, after all, we are trying to reach the 640K limit here. This also requires not one but two IBM Memory Expansion boards, one with 256K and one with 128K.

The video displays for this machine are based off the IBM Monochrome Display and Printer Adapter and the IBM Color/Graphics Adapter. While one could use the Enhanced Graphics Adapter (too AT) or the Video Graphics Array (PS/2 territory), the programs that run well on these cards tend not to run so well on the 5150. They are also not quite 100% compatible with the CGA adapter. For similar reasons (and the fact that it won't fit in the slots), the Professional Graphics Controller is a no-go. More importantly, you can use both displays in a dual setup using the MDPA and CGA cards, and you have a printer port to boot. The display devices would be the 5151 Monochrome Display and the 5153 Color Display.

For other peripheral cards you should have a Game Control Adapter, two Asychronous Communications Adapters and a Printer Adapter. I did not include the Binary Sychronous Communications Adapter or the SLDC Adapter because there is not much you can do with them in this day and age, and unless you were connected to a mainframe or computer network, you wouldn't need one. And what do we connect to these adapters? Well, the 5182 Graphics Printer is a solid printer. IBM did not make its own mice until the PS/2 days, so a Microsoft Mouse (25-pin Green Eyed serial variety) will do. IBM did not may joysticks with a 15-pin connector, so a Kraft joystick that functions like the PCjr. joystick is the best alternative.

Finally, we observe that we have 9 cards and five slots. Obviously, things will have to be moved around every so often. Unless, of course, you buy an IBM Expansion Chassis. Here, you will have the opportunity to add two 10MB hard drives to your system. You will no longer have to shift cards, in fact you will have an empty slot!

 

[frozenfire75i]

I have one just like that ;-) Have a look. The tree is real.

 

[Fallo]

There is such a thing as a perfect IBM PC 5150, just that you can't really use it all at once (except in one instance).

My vision of the perfect IBM PC uses only IBM parts unless otherwise non-existent. It embodies the height of compatibility and functionality. However, I would stress that it is not an earliest IBM PC, nor is it the most treked out IBM PC you could ever buy.

The IBM PC Model 5150 has five expansion slots (8-bit ISA), a co-processor (8087) socket and two full height drive bays. IBM's maximum configuration put two full-height 5.25" floppy ("diskette") drives in those bays, filling them up (and the Adapter for them). The power supply IBM used, a 63.5W box, could not support the large drives that were used back in the day. Obviously, that 8087 coprocessor socket should be filled with an 8087, which IBM did offer as an option.

While a 5150 could have a hard disk or a 3.5" floppy, somehow it only looks right with the dual full-height floppies.

The motherboard should be 64/256K motherboard, after all, we are trying to reach the 640K limit here. This also requires not one but two IBM Memory Expansion boards, one with 256K and one with 128K.

Well, yeah. The 16k-64k models really have only historical value. For practical purposes, you would want the 64k-256k 5150.

The video displays for this machine are based off the IBM Monochrome Display and Printer Adapter and the IBM Color/Graphics Adapter. While one could use the Enhanced Graphics Adapter (too AT) or the Video Graphics Array (PS/2 territory), the programs that run well on these cards tend not to run so well on the 5150. They are also not quite 100% compatible with the CGA adapter. For similar reasons (and the fact that it won't fit in the slots), the Professional Graphics Controller is a no-go. More importantly, you can use both displays in a dual setup using the MDPA and CGA cards, and you have a printer port to boot. The display devices would be the 5151 Monochrome Display and the 5153 Color Display.

I'd go with a Hercules card over the MDA, although I've found that some software (Sierra games for instance) insists on using B800 for the Hercules graphics instead of B000. As you can imagine, this doesn't work too well in a dual-display system. EGA might be better in a turbo XT (XT-class PCs equipped with an 8086 or an NEC V20), because it's graphics use between 32k and 128k of video memory, and as a consequence are pretty sluggish on a 4.77Mhz 8088. VGA is a no-go for the same reason. I'd also use a composite monitor with the CGA (for more colorful games), although the 5153 might be useful for certain things (like games that use the cyan/red/white palette).

For other peripheral cards you should have a Game Control Adapter, two Asychronous Communications Adapters and a Printer Adapter. I did not include the Binary Sychronous Communications Adapter or the SLDC Adapter because there is not much you can do with them in this day and age, and unless you were connected to a mainframe or computer network, you wouldn't need one.

You could always use a network card to connect the 5150 with a modern PC, making the transfer of files easier. As for serial ports, I'd only really use them for a mouse.

And what do we connect to these adapters? Well, the 5182 Graphics Printer is a solid printer. IBM did not make its own mice until the PS/2 days, so a Microsoft Mouse (25-pin Green Eyed serial variety) will do. IBM did not may joysticks with a 15-pin connector, so a Kraft joystick that functions like the PCjr. joystick is the best alternative.

Myself I'd just use an AST Six-Pak for the memory, joystick, and serial port. The Six-Pak along with the CGA, monochrome, and floppy controller would occupy four of the 5150's five slots. The fifth could just be used to hold a mounting bracket with a game port that connects to the Six-Pak. You said in a previous post that it only supports 2-button, 2-axis joysticks. In that case, one could put an IBM Game Control Adapter in the fifth slot instead, although I don't know of any games that run on an XT and use four buttons (maybe some flight simulators?).

I actually want to get an IBM GCA for my Pentium, since there isn't any other decent way to put a game port in it. Multifunction cards won't work, and it would be pointless to get a sound card with one, because the computer already has an integrated sound card (with no game port).