• Please review our updated Terms and Rules here

PDP-8/E Omnibus unexpected behavior

AK6DN

Veteran Member
Joined
Aug 23, 2010
Messages
1,014
Location
Silicon Valley USA
The PDP-8efm Maintenance Manual volume 1 pp 3-96 thru 3-106 has a very detailed description of how the programmer's console logic operates.
 

BitWiz

Experienced Member
Joined
Sep 7, 2021
Messages
235
Location
Glen Ellyn, Iil
I figured as much and TP4 is the obvious place to latch the address if you are a memory board. Clearly not quite what he was looking for here. Looking forward to hearing if SOURCE does what he wanted. It still wont latch on the Load Addr switch press which probably means it still won't be exactly what is wanted.

As long as the the address latched is the address of the data represented on the MB lights I will be happy. It doesn't have to be when ADDR LOAD is pressed but can be after DEPOSIT or EXAM is pressed.

Thank you.
 

BitWiz

Experienced Member
Joined
Sep 7, 2021
Messages
235
Location
Glen Ellyn, Iil
The address information is permanent on the bus. So you just need a driver for the LED, you don't need to latch anything.

The latch is specifically to handle the fact that the address is the next address not the current address and to handle any transitions on the bus that don't need to be displayed.
 
Top