jplr
Experienced Member
Hi all,
I am considering building my own QBus Q/Q with wire-wrap for LSI-11 cards, because finding an existing one is difficult and costly.
For connectors it looks to me that Vector R600 edge connectors or similar fit the cards' connectors.
I read too quickly the chapter 6 of the LSI-11 bus specification.
Do I understand correctly that most lines are multiplexed on all slots, for example:
- A given BDAL line in one slot is electrically connected to the same BDAL line in other slots.
- Same for the control signals such as BSYNC, BDIN, BDOUT,.
- Same for electric power lines where there are special signals such as Binit, BDCOK, RTC and power OK.
An exception is the bus control signals (TDMR, TSACK, etc) which are connected in round robin.
Another exception is the interrupt lines with one interrupt line is affected to only one card.
All multiplexed lines should be terminated by a 120 ohms resistance.
If possible I would like to address 32Kb or even 48Kb, what must I know?
What precautions for mitigating cross-talk between wires and minimizing capacitances on lines?
Thanks for your answers!
Jean-Pierre
I am considering building my own QBus Q/Q with wire-wrap for LSI-11 cards, because finding an existing one is difficult and costly.
For connectors it looks to me that Vector R600 edge connectors or similar fit the cards' connectors.
I read too quickly the chapter 6 of the LSI-11 bus specification.
Do I understand correctly that most lines are multiplexed on all slots, for example:
- A given BDAL line in one slot is electrically connected to the same BDAL line in other slots.
- Same for the control signals such as BSYNC, BDIN, BDOUT,.
- Same for electric power lines where there are special signals such as Binit, BDCOK, RTC and power OK.
An exception is the bus control signals (TDMR, TSACK, etc) which are connected in round robin.
Another exception is the interrupt lines with one interrupt line is affected to only one card.
All multiplexed lines should be terminated by a 120 ohms resistance.
If possible I would like to address 32Kb or even 48Kb, what must I know?
What precautions for mitigating cross-talk between wires and minimizing capacitances on lines?
Thanks for your answers!
Jean-Pierre