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Wozniak's Original System Description of the Apple ][
CowboyRobot writes "Opening with the line, 'To me, a personal computer should be small, reliable, convenient to use and inexpensive,' Steve Wozniak gave his system description of the Apple-II in the May, 1977 issue of BYTE. It's instructive to read what was worth bragging about back then (PDF), such as integral graphics: 'A key part of the Apple-II design is an integral video display generator which directly accesses the system's programmable memory. Screen formatting and cursor controls are realized in my design in the form of about 200 bytes of read only memory.' And it shows what the limitations were in those days, 'While writing Apple BASIC, I ran into the problem of manipulating the 16 bit pointer data and its arithmetic in an 8 bit machine. My solution to this problem of handling 16 bit data, notably pointers, with an 8 bit microprocessor was to implement a nonexistent 16 bit processor in software, interpreter fashion.'"
I was in high school working in a retail computer store in 1978 when the Apple ][ and its competitors were taking hold in the market. The Apple was the only computer with high-resolution color graphics for under $5000. I could tell just by looking at its motherboard that its design was something special - having built a video display board from scratch with my brother, I knew how much circuitry is usually required.
The determined Real Programmer can write Fortran programs in any language.
Here's the very strange thing about that error. I have a scan of that issue of Byte and it does indeed say 553 there. The article also has a circuit diagram, again showing a 553. If you look at the original Redbook schematics, it also shows a 553 quad timer. There is even advert for 553 quad timers on page 174 of that issue of Byte. I've also seen a post online from someone with a 553 chip in an apparent timer circuit asking about it's identity. All that and no datasheet or cross reference for a 553 quad timer can seem to be found. My best guess is 553 comes from an imprinting error on actual 558 chips.
+0 Meh