Introduction
Over the past year, I have been writing an emulator for the original IBM PC Model 5150, and its slightly more advanced brother, the IBM XT M...| martypc.blogspot.com
In the early 1990s, the games industry found itself on the edge of a revolution. For more than a decade, developers had battled against the limited capacities of floppy disks. Graphics, audio, and every line of code had to be squeezed, trimmed, and compressed until barely fitting into a handful of megabytes. With the arrival […]| Retro365
This is part 6 of a series of articles investigating various floppy copy-protection schemes seen on the IBM PC platform. You may wish to read the previous entries in this series:| Adventures in PC Emulation
This is part 5 of a series of articles investigating various floppy copy-protection schemes seen on the IBM PC platform. You may wish to read the previous entries in this series:| Adventures in PC Emulation
This post goes hand-in-hand with my article on Vault Corporation's Prolok copy-protection technology. Perhaps the most important historical legacy of Vault Corporation results from the lawsuit they initiated against Quaid Software, makers of the backup software CopyWrite. | Adventures in PC Emulation
This is Part 4 of a series on PC floppy copy protection methods. You can read the previous parts here: | Adventures in PC Emulation
This is Part 3 of a series on PC floppy copy protection methods. | Adventures in PC Emulation
This is part 2 of a series on PC floppy copy protection methods. You can read Part 1, covering Formaster Copy-Lock here.| Adventures in PC Emulation
In a previous article, I described a simple state machine to explain the prefetch behavior and miscellaneous observed bus delays of the Intel 8088. I now believe that the model I described there - although successful in modelling the 8088's behavior - was unnecessarily complex. There are in fact far fewer legitimate bus "delays", and they do not relate to internal state transitions. I have also slightly revised my description of the BIU's prefetching logic - I now believe that the prefetching...| Adventures in PC Emulation
My emulator has a bug. | Adventures in PC Emulation
Over the past year, I have been writing an emulator for the original IBM PC Model 5150, and its slightly more advanced brother, the IBM XT M...| martypc.blogspot.com
‘Let us therefore brace ourselves to our duty and so bear ourselves that if the British Empire and its Commonwealth lasts for a thousand years, men will still say, “This was their finest hour”’ – Winston Churchill, 1940 In the summer of 1940, the world watched as the skies over Britain became the stage for […]| Retro365
By the late 80s, Spectrum Holobyte was in the midst of major changes. Originally founded in 1983, the company had established itself with high-end simulation and strategy games. In 1987, Spectrum Holobyte merged with another software house, Nexa Corporation, founded by Gilman Louie, a young entrepreneur with a strong interest in simulations and emerging computer […]| Retro365
In my last article , I dodged the issue of writing a custom decoder for the 5150's bus signals to use in DSView, instead just processing the...| martypc.blogspot.com
Writing a cycle-accurate emulator for a computer system is more than just understanding all the CPU instruction timings. A computer is a com...| martypc.blogspot.com
The Book8088 is an interesting little machine. It is essentially a 1980's computer in a laptop form factor. With apologies to Sergey Kiselev...| martypc.blogspot.com
In a previous article, I revealed one of the secrets to MartyPC 's accuracy, hardware validation . To summarize, it is a method of using a m...| martypc.blogspot.com
Much has been written about the PC demo 8088MPH . If you haven't seen this demo yet, take a moment to watch it. If you're familiar at all ...| martypc.blogspot.com
⚠ This post is now outdated. Although the logic described here will correctly model the externally observed behavior of the 8088,...| martypc.blogspot.com
My emulator has incomplete implementations of the EGA/VGA cards. Since these cards share a lot of common functionality and register architec...| martypc.blogspot.com
Early in development I was looking for a utility to test my crude PC speaker emulation. I found a simple keyboard-piano program called PIAN...| martypc.blogspot.com
In the emulation world, there are a few different ways to determine if your emulator is accurate. The traditional way has been through the ...| martypc.blogspot.com
In order to accurately emulate cycle-counted demo effects such as the Kefrens bars effect in 8088MPH, or the end credits in Area 5150, there...| martypc.blogspot.com
DMA, or Direct Memory Access, is a scheme that allows peripherals access to system memory without the assistance of the CPU, which normally ...| martypc.blogspot.com
“Now computing can be fun and easy for the entire family.” The Tandy Sensation was an early attempt at a specialized Multimedia PC. In this case, Tandy came up with a 25 MHz 486SX computer with a 107 MB hard drive, built-in CD-ROM drive, stereo sound card, a voice/fax modem, SVGA color graphics, and more. […]| Vintage Computing and Gaming
