[sebhc] H8 optoisolators - aka: disk transfer program

[Steve Thatcher]

I suspected that. It was the cheap alternative... :) You want to talk cheap though, try doing a serial connection on the original Osborne computer. If I recollect correctly, they used a quad LM3900 transconductance amplifier for the interface. I developed debugging software (EM-PAC) to control Applied Microsystem EM series emulators and remember dealing with Osborne issues.

best regards, Steve


---snip---
>
>By the way, did Heath use 1488 and 1489 chips for the RS232 along with the 
optoisolators?
>
>best regards, Steve
>
---snip---

 They only used the optos on the H8-5 without any 1488/89's.
On the H8-4 they used a more traditional interface.
Dwight

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