Tag Archives: PCjr

The myth of the vertical retrace interrupt

This is a draft from March 18th, 2019. We’re slowly cleaning out the backlog. The few remaining drafts are going to take more time to work into an article though, as actual code or configuration is required to work out … Continue reading

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The DreamBlaster S2P: General MIDI from a parallel port

In the interest of catching up, here is the second blog that is long overdue. I want to talk about the DreamBlaster S2P from Serdaco. I received mine over a year ago, and it actually was an early prototype. The … Continue reading

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Putting the things together, part 2: MIDI and other problems

Remember a few months ago, when I explained my approach to playing VGM files? Well, VGM files are remarkably similar to Standard MIDI files. In a way, MIDI files are also just time-stamped captures of data sent to a sound … Continue reading

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More PC(jr) incompatibilities!

The race for PC-compatibility Since the mid-80s, there have been many clones of the original IBM PC. IBM themselves also made new-and-improved versions of the PC, aiming for backward-compatibility. DOS itself was more or less a clone of CP/M, and … Continue reading

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Putting the things together

So, over time I have discussed various isolated things related to 8088-based PCs. Specifically: Using the latched property of the 8253 programmable interval timer to be able to adjust the interval without any jitter/skew, so you can use it as … Continue reading

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PC-compatibility, it’s all relative

Update 21-12-2015: I have updated some of the information after testing on an AT with old Intel 8259A chips, and added some extra information on EISA and newer systems. I would like to pick up where I left off last … Continue reading

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Just keeping it real… bugfixing like it’s 1991

As you may have noticed, the 1991 donut intro did not have any music. I did not cover it in the previous blog, but there was some music planned for this small intro. I chose to use EdLib, because AdLib … Continue reading

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Just keeping it real… like it’s 1991

Last weekend, there was a special demoscene party, the 1991 party, with, obviously, 1991 as a theme. Well, that is just my bag, baby! The focus was mainly on C64 and Amiga, which were the most popular platforms for gaming … Continue reading

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