ibm pc - Identifying IBM PC SIMM RAM size - Retrocomputing …
Dec 15, 2024 · I am trying to restore an IBM-compatible pc from the mid-90s. I have some SIMM ram blocks I could use, but I have no clue on how to identify the ram size. Any help would be appreciated. Edit: picture
ibm pc - Why weren't there games that use CGA 16-color low res …
Oct 27, 2024 · It required some care to avoid snow on the original IBM PC, and was different to program compared to typical graphics. Gaming on the PC wasn’t hugely popular until EGA and more so VGA, and managing text-mode CGA support alongside graphical EGA/VGA or even as a port from another platform was perhaps too much work for too little gain.
ibm pc - Origin of CHS geometry limits in BIOS calls
Oct 21, 2024 · The first hard drives appeared later on IBM 5160 PC/XT and the first drives were 10MB, with parameters of 306 cylinders, 4 heads, and 17 sectors per track. The XT hard drive adapter had a separate hard disk BIOS which hooked the INT 13H to provide hard disk as drive 80h and as a fallback for other drives called the motherboard BIOS for handling ...
ibm pc - Who set the 640K limit? - Retrocomputing Stack Exchange
Oct 1, 2018 · There was a 640K limit on the original IBM PC, but it was the result of IBM’s design decisions, and nothing to do with Microsoft: it’s the largest contiguous amount of memory which can be provided without eating into reserved areas of memory. The IBM PC Technical Reference includes a system memory map (page 2-25):
ibm pc - How is it possible to connect more than two floppy drives …
Jan 21, 2018 · Hardware-wise the PC floppy controller also supports this. But as the original housing only allowed two (full height) drives, the controller thus split the interface onto two (proprietary) connectors: one PCB header for up to two internal drives, and a DB37 for two external drives (separate housing).
What were the real competitors to the early IBM PC?
Jul 11, 2018 · While the IBM PC marketing was a major feat pulled out by IBM+Microsoft, the IBM PC hardware together with the DOS OS was a throwback at least 1 decade in the past for 8-bits hardware, CP/M compatibility, and terrible sound and graphics capability that still haunts us to …
ibm pc - IBM PC Alt + numpad for entering character codes: …
Aug 15, 2022 · The IBM PC keyboard behaves as though it holds a bitmap of every key that is pressed or released, and repeatedly scans the keyboard, comparing the present of each key with the state in the bitmap. It also maintains a tick count of how many scans have been performed since the last difference was observed.
ibm pc - How can I connect a DIN plug keyboard to USB?
Jun 20, 2017 · Although the pinouts are not too bad. The IBM DIN and PS/2 sockets have pins as below: 1: Clock 2: Data 3: Reserved (in practice, usually a reset line) 4: Ground 5: +5V . I would suggest: Use a USB-RS232 adaptor and wire the DIN plug to a DB25 or DB9 RS232. The keyboard will then appear to the PC as being on a standard COM port.
Floppy drive detection on an IBM PC 5150 by PC/MS-DOS
Aug 20, 2023 · Since function AH=08 (Get current drive parameters) is unavailable, how does PC-DOS/MS-DOS detect the number and type (e.g. 180 kB or 360 kB) of floppy drives on a pre-XT machine? I am particularly interested in the original IBM PC 5150, but the question extends to all pre-XT systems. I am not referring to the "DIP switches vs. ROM BIOS" issue.
How to repair paint on IBM PC? - Retrocomputing Stack Exchange
Dec 31, 2017 · Like you, I had an IBM PC in need of paint restoration. I used the Pantone 413 suggestion and the result.... drum roll please: Repainted PC on left, factory PC on right. TL;DR (my experience) My PC unfortunately had large areas where rust had completely eaten away the original paint to the point that it was not save-able (pic, pic). I was able ...