The hidden program on a blank tape...

Anything Sinclair ZX Basic related; history, development, tips - differences between BASIC on the ZX80 and ZX81
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TMD2003
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The hidden program on a blank tape...

Post by TMD2003 »

No, really! Well, sort of. For anyone who's heard of 8-Bit Show And Tell (it's not The 8-Bit Guy, and they're not even in the same country), he was tipped off that there was a blank Computer Cassette available in 1982 that had a program printed inside the J-card for the computers of the day.

The rumours were true. He tracked one down - an unopened original! - and inside, there were two programs, one for the VIC-20 and one for the ZX81; likely as not, the Spectrum hadn't been released yet, and the C64 certainly hadn't. 41 years later, but the programs have resurfaced... and 8BSAT even types them in on real hardware as part of the video, having some trouble with finding how to make the ZX81 print INKEY$, and with the keyboard in general.

https://www.youtube.com/watch?v=7fnkSJgPYRc

The program is so small that it doesn't trouble the unexpanded ZX81 with any intrusion into the screen memory, let alone the VIC-20's thromping three kilobytes, and anyone even remotely familiar with either kind of BASIC will clock what it's doing straight away, although Commodore BASIC makes it less obvious with its arcane POKEs. So I won't spoil the surprise. It takes a couple of minutes to type in yourself, and can be seen on screen clearly.

This might have been really exciting for someone who'd just obtained a VIC-20 or a ZX81 back in the day.
Spectribution: Dr. Jim's Sinclair computing pages.
Features my own programs, modified type-ins, RZXs, character sets & UDGs, and QL type-ins... so far!
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TMAOne
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Re: The hidden program on a blank tape...

Post by TMAOne »

Very cool video, even if a tiny bit tedious. And a neat little program for these humble machines. Thanks for posting this.
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bobs
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Re: The hidden program on a blank tape...

Post by bobs »

I remember these from back in the day, I had quite a few. You’d be kinda curious about the program, but knew it wouldn’t amount to much as the type-in listings in the magazines and books of the day would be much longer to produce anything of merit.
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