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One of the hacks I always wanted to do ( and still looking for parts for) is a flame speaker. I plan to do it outside maybe even in a bonfire if I can keep the wires from melting.

you can get plenty of flame speakers on the /. comments.

One of the hacks I always wanted to do ( and still looking for parts for) is a flame speaker. I plan to do it outside maybe even in a bonfire if I can keep the wires from melting.

Don Lancaster's TV Typewriter in Popular Electronics

This was one way of putting characters on a screen in 1973 - Woz's approach simplified it substantially... (the entire Apple ][ used fewer chips ;^)

...had a kit project to build a "digital" video camera. The "MOS sensor" that it used was, as I recall, essentially a DRAM with a transparent cover -- in fact, people were prying the lids off standard DRAM chips to use them as image sensors. (Decades later, I verified that you could detect bit-flips in an erased EPROM when you hit it with a red laser pointer. Forget high-ISO night photography; this was probably somewhere around ISO 0.5.)

You could then presumably build an interface to load the image into your Altair 8800 box, presented in the previous month's issue. At some point in the next few months, they even ran a project for a bit-mapped graphic display. Those were the glory days of Popular Electronics.

But I always meant to do something with my copy of the TV Typewriter Cookbook.

http://www.swtpc.com/mholley/RadioElectronics/TV_Typewriter.htm

If you are trying to read old floppies, this may be helpful: How to recover data from an improperly stored floppy diskette

the first mass produced computer for the home was probably the Altair. The first with a video display was, I believe, the Apple ][

The Apple II was launched in 1977, but was preceded by the Apple I in 1976 and the much more sophisticated Processor Technology Sol-10/Sol-20 (8080 with S-100 expansion bus) which not only had a video display but also (unlike the Apple I) came in a nice case (with mahogany sides!) with a keyboard. A hulking "Helios" dual 8" floppy drive was also an option for the Sol-20.

But I'd guess there must have been a few Altair's (launched in 1975) conected to Don Lancaster's "TV typewriter" video terminal (Radio Electronics 1973)that would also compete for the earliest PC with a video display.

http://www.swtpc.com/mholley/RadioElectronics/TV_T ypewriter.htm

Hey, I didn't know you could use Windows with a "dumb terminal"! I guess it's time to dig out the ol' TV Typewriter!

Dad bought and built a SWTPC kit for me for Christmas.
Then since I was too lazy to learn 6800 machine language, he wrote Basic for it.

http://www.swtpc.com/mholley/BASIC_2/Uiterwyk.htm

Southwest Technical Prod's 6800. 14 minutes to load BASIC from cassette. And we had both A$ and B$ to play with!

http://www.swtpc.com/

Got a reference that shows floppy drives with 2 opposing heads?

To Google!

The difference between single and double sided drives is obvious -- the double sided drive has an extra head (mounted on top of the disk) and a switching circuit to select between the 2 heads. Reference.

I remember buying "DS" 5.25" floppies, and having to flip them.

Some people did just that -- they formatted both sides of the floppies as single sided and flipped them. It made some of the older generation more at ease -- how could a machine read both sides-- and the younger who felt that they were putting one over on the computer -- I just gave you the other side, and now it has different data! I just marveled over how it was able to synch up two heads and come up with the same output twice in a row.

And I started with 90KB floppies. The doubling densities (90->180->360->720->1.4) were achieved by tighter cylinder counts - not by producing a hyper^4cylinder.

I don't remember 90KB floppies, only 160KB (?), 180KB, 360KB and 1.2MB. Then we hit the 3.5's and used 360KB, 720KB and 1.44MB.

Ok, it'll be beaten to death here, but here's the numbers:

The shortest video they have, at 2 MB and just about a minute, would take 19 hours to download at 300 baud. More time if there were any errors (the 300 baud modems didn't error-correct; that was done in software).

The same video at highest quality (22.9 MB) would take 9.25 days to download... for a minute of video.

Never mind that this would take 15 and 168 Apple ][ disks (respectively), and that the high quality version would require almost 3 disk changes a second during playback. The old drive heads would take over a second just to move across the disk, much less read any data.