Checkout my recently acquired Hayes Stack Chronograph. Why? "He's gotta have it!"

I didn't have a power supply for the chronograph, so waited a week for a Hayes SmartModem 1200 I bought to be delivered to rob it of it's power cube. I actually bought a second modem for a spare wall wart.

It works except that result codes and data reads are returned. I can set the date and time and change the display. I've replaced the three AA batteries.

Might put it on the bench today after breakfast.

I put up a wiki page for my Hayes Stack Chronograph https://wiki.theretrowagon.com/wiki/Hayes_Stack_Chronograph

This is my previous Telephonic modulator demodulator Chronographicaly enhanced stack. // @paulrickards @BillLange1968

I've got the Chronograph on bench now. I know it's responding to received data, so I'll be looking at xmit data to repair. To be sure I have my instrumentation working to my understanding I setup my Rigol on pin 1 of U9 MC1489 to decode RS232. It works! ;-) Next it's U10 MC1488

O.K. I've got signal coming from the PIC into U10 1488 but no -10vdc on VCC- Checking that part of the power supply now.

ACK! Not like acknowledge, like DOH but I already used DOH in this thread.

I blew the fuse :-(

Break time.