ibm pc - Who set the 640K limit? - Retrocomputing Stack Exchange
2018年10月1日 · The "640k limit" (hole in contiguous RAM) was just 1 of a series of short-sighted, odd, and/or bad decisions involving the PC. Others include a) IBM choosing 8086 family over 68000. b) IBM not buying MSDOS outright instead of …
ibm pc - Why weren't there games that use CGA 16-color low res …
2024年10月27日 · 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
2024年10月21日 · 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 - How can I connect a DIN plug keyboard to USB?
2017年6月20日 · 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.
ibm pc - What makes a floppy disk bootable? - Retrocomputing …
2017年12月27日 · I'm interested in making my own bootable floppy images for an IBM PC. Write the program to be executed (like this minimal one) to Sector 0 Track 0 and press reset. [I] want to understand the details. It's that simple. The BIOS looks for a floppy in drive 0, reads the first block and starts whatever is located there.
Newest 'ibm-pc' Questions - Retrocomputing Stack Exchange
2024年12月13日 · PC-98 was a series of x86-based Japanese computers that offers Kana-Kanji support, which shared some hardware similarities and operation systems with IBM PC, and software was relatively easy to port ...
ibm pc - How is it possible to connect more than two floppy drives …
2018年1月21日 · 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).
IBM PC 5150 board layout - Retrocomputing Stack Exchange
2020年6月22日 · While this is still true today, it's even more relevant for back then, when a board like for an Apple II or IBM-PC wasn't layouted in five days, but took several weeks, if not month of intense work (*1). Having said that, there are also several practical reasons. Having chips nicely aligned eases layout, simplifies debugging and likewise patching.
What were the real competitors to the early IBM PC?
2018年7月11日 · 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 …
ibm pc - What were the differences in floppy disk formats …
When IBM is involved, it's all about history. IBM's first PC floppy disk format was single sided, 5-1/4", 160K on a single-sided drive. (40 tracks, 8 sectors per track, 512 byte sectors). This started as "double density" but was otherwise a conservative design, typical for IBM. Double-sided floppies were 320K, of course.