First post, by AlessandroB
I came into possession of an intact IBM 5150, exactly as it left the factory, with 64 / 256k mainboard, latest BIOS revision, Monitor 5151 and the coordinated IBM printer.
Since everything is perfectly preserved, and working, I thought of studying this system and seeing what it is possible to achieve, comparing it to the systems that succeeded it.
Reading on the internal components (only the MDA graphics card and the controller card for the two floppy drives) I understood that in order to use it in a profitable way it is necessary to expand it. At this point, however, I wondered how much of the correct period system remained...
The components that according to my analysis are to be expanded are the following:
1)Video Card. The video card is probably the fundamental component since the serial card is only capable of drawing characters and no graphics. So I chose an excellent card, an ATI wonder 16, this card is capable of driving the 5151 monitor as CGA graphics and also has a 15 pin output for EGA and VGA as well as a mouse port.
2)Hard disk, the mfm disks of the time I know are quite fragile and noisy and in addition I did not want to remove one of the two floppy drives because I consider the most characteristic dual player and keeps the shape of the computer more faithful to the original. porendero an xt-cf lite v4 card. This is the only modern component but I think in this case it is more important than the correct period also considering that the serial computer had no hard disk (also considering the low amperage of the power supply).
3)RAM, as standard I only have 64Kb which is too little for almost anything, I will have to get the chips to expand the mainboard to the maximum plus another ram expansion card to bring it to 640 or 512, this I have not yet understood...
4)CPU, standard mounts an 8088 at 4Mhz, already at the time it was replaced with a NECV20 and in addition there is a chip to put in place of the chip that generates the frequency to bring the cpu to 8Mhz. Both the CPU and the coupon should be correct period
5)At this point, only 1 of the 5 ISA slots remains free (MDA-VGA-Floppy controller-XT-CF). I thought of taking a sound card of the time, I have a sound blaster 2.0 it may be too recent but perhaps not much.
What do you think of my thoughts on the correct period and on the reasons for being bordeline on the correct period? I want to clarify that any modification is reversible and at any time the computer can be restored to 100% original. No physical changes are made.