aerocomp double density adapter

[Gary C]

Does anyone have a schematic of the aerocomp double density adapter ?

I have one for a trs80 model i and the 1771 works fine on its own but when the aerocomp is in, no joy. I notice that the data from the disk drive is getting to pin 27 of the 1771 but the pulse is very very narrow compared to what it is on its own, so possibly the data separator isn't working properly. It is gated through a gate with a clock which is running at 140khz which is adjustable.

Any ideas or diagrams ?

 

[Gary C]

Data signal passes through a 74LS221 monostable multivibrator whos TC is set by a capacitor & a resistor, so I think it might be worth changing the 47pf (?) capacitors (470JI)

 

[ldkraemer]

Here are the Aerocomp Documents I have for the Model 1. I haven't verified them with my
Model 1 Aerocomp DD Controller.

Larry

 

[Gary C]

Thank you.

Hopefully will get it up and running with this.

 

[ldkraemer]

Yes, and if you have a slightly different circuit from the schematic, be sure to note it so we can update the
current information. I have no clue where I downloaded those files over the years.

Larry

 

[fjkraan]

There is a schematic at http://knut.one/Archive.htm. Based on this I created a board, but haven't build and tested it.

Greetings,
Fred Jan