[sdiy] Matrix 1000 repair, unexpected hack

[Andre Majorel]

On 2007-04-29 23:26 +0200, . wrote:

> After opening [a Matrix 1000], i stumbled across a weird thing,
> pin24 (Clear to Send) of the 68b50 ACIA (IC U809) is
> purposefully unsoldered and left unconnected (by human
> intervention) and the timer(UM82C54) U808 just aside it has a
> wire directly solderd on pin 14 (Gate 1). The wire is cut at 2
> centimeters and left unconnected too.
> 
> Theses 2 chips, U808 and U809, are involved in MIDI handling but
> so far MIDI IN and OUT seem to work OK, should i worry about the
> CTS not connected ?

I'm not familiar with the 6850 but CTS is a hardware handshaking
signal and as such does not apply to MIDI. If there's an internal
pull-up, you can leave CTS unconnected (or so I expect).

-- 
André Majorel <URL:http://www.teaser.fr/~amajorel/>
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