31 Jan
2023
31 Jan
'23
4:48 a.m.
On Mon, Jan 30, 2023 at 5:34 PM Jim Brain via cctalk
<cctalk(a)classiccmp.org> wrote:
On 1/30/2023 11:14 AM, Chris via cctalk wrote:
Yes, all those have dedicated cassette ports.
It had a dedicated cassette port? Don't
most cassette ports resemble a serial port, or is my wonky brain making that up? What
protocols did most cassette ports use (c64/128?, IBM 5150, coco ...)?
Lots of systems had dedicated cassette ports, but yes, CoCo has a
dedicated cassette port, as does all the 8 bit CBM machines, I think the
Model 1/3/4 also, and doesn't the Apple II have one as well. I am sure
I am forgetting a bunch.
ZX80, ZX81, Spectrum, Acorn Acom, Acorn Electron, BBC Micro, etc, etc.
Do you count machines like the Amstrad CPC464 which had a built-in
cassette recorder?
I think it would have been hard to have the cassette use the serial
port, because cassette needs audio tones, not RS232 levels.
There was an almghty kludge in the TRS-80 Modem 1. You could flip a
switch and the modem serial input changed from RS232 levels to
cassette levels. The modem serial output became a keyed (by the serial
data) audio tone. This meant you could link it to a Model 1 cassette
port and drive it with special software. It's documented in the
service manual for said modem.
-tony