Paul
Fri Jul 01 10:42:25 CDT 2005
"Andrew Howell" <ajh@work> wrote in message
news:OBVojFhfFHA.352@TK2MSFTNGP09.phx.gbl...
> "Paul Pedersen" <no-reply@swen.com> wrote in message
> news:ONo$yWafFHA.1472@TK2MSFTNGP12.phx.gbl...
> > The C-64 used a truly unique error checking algorithm with its tape
> drive.
>> When it wrote to the tape, it would write the exact same thing twice in a
>> row (making an already painfully slow process excruciating). Then when it
>> read the tape, it would read the first copy, then read the second copy
>> (slow!) and compare it to the first one. If they matched, all was well,
>> and processing continued. If they didn't match, the computer would crash.
>
>
> Ah, the datasette. I never knew that. Although I've talked to various
> people who made "turbo loaders" (Novaload was one.) I guess there was a
> small loader on the tape twice, and this loader bypassed the dual copy
> requirement. Or something.
I remember reading about that in one of the magazines.
But storing data on an ordinary audio cassette was a great idea. Simple and
cheap, but slow.
I had a plug-in cartridge turbo loader that would handle that. I think it
just skipped the second reading. Cut bootup time to two seconds, too, but
couldn't use it with the modem because they took the same slot.
Around 1990 I had a C-64 emulator that would run on a Macintosh (68030,
roughly equivalent to a slow 386). Even under emulation, it ran programs way
faster than the original.