Category Archives: Retrocomputing

RC2015/01 entry

My RC2015/01 project is to reverse-engineer and restore a 16-bit microcomputer (not a minicomputer!) that was sold in 1976, and design and build a memory upgrade and serial interface for it. If there’s time left after that, I’ll try to … Continue reading

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RC2014SC wrapup – declaring victory

My primary accomplishment for this RetroChallenge was making substantial improvements to my standalone floppy disk formatter program for the Quay 900. In the course of trying to find information about the Quay, I created a consolidated advertiser index for the … Continue reading

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Recreating Z80 Micro-Reference Manual in LaTeX

Mostek published a great little Z80 reference card called the “Z80 Microcomputer System Micro-Reference Manual”.  In addition to the Z80 CPU, it covers the PIO, CTC, and SIO, but not the Z80 DMA.  Unfortunately it’s long out of print, so … Continue reading

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Quay 900 CP/M porting progress

I’m way behind on reporting on my Retrochallenge project, but I have been working on it. As Dr. Asimov wrote, “Sloane’s Teddy Wins the Race.”  I’ve made progress porting CP/M to the Quay 900.  I’ve improved my disk routines, added … Continue reading

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Better error recovery in floppy disk formatter

I put some better error recovery code in floppy disk formatter for the verify pass.   Previously I was getting verify failures on drive 0 when using double density, and the new code reveals that some of them are cleared up … Continue reading

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Quay 900 internal photos

Mark Wickens asked for photos.  I haven’t taken many, but here are two.

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Quay floppy formatter

I did a lot of cleanup of my floppy routines, and got the formatter working with double density.  Right now it only runs as a “standalone” program.  Once I have CP/M running on the Quay, I’ll put in conditionals to … Continue reading

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BYTE conolidated adveriser index for vol 1 & 2 available

I’ve added volume 2 to the BYTE consolidated advertiser index.  It is provided as an ODF (Open Document Format) spreadsheet.

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BYTE consolidated advertiser index, Quay ads, 8080 XPL0

I’ve been compiling a consolidated advertiser index for the early years of BYTE magazine, thus far from V1N1 (September 1975) through V2N3 (March 1977).  Hey, that’s one more thing to add to my Retrochallenge project! This did turn up some … Continue reading

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Quay 900 stuff

I have a Quay 900, which is an obscure Z80-based system from 1979.  It has two MPI (CDC) eight-inch double-sided floppy drives, and uses a Quay MPS-90F single-board computer rather than the then-common S-100 bus, though it has two daughterboards … Continue reading

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