saipan59
Experienced Member
Hi Mark, attached are schematics.
One shows the time base used on the clock. Datasheets are on the web.
The other is for the T11 wire-wrap board. It's quite a mess...
The stuff in the lower-left corner (HC595's) was never implemented. It was a plan to make an interface that would be driven by a modern MPU, to DMA code into the RAM for the T11. I was going to use an MSP430. Every time on power-up, the MSP430 would load the T11's RAM and let it run. So, the T11 wouldn't need any EEPROM. The HC595's were a serial-to-parallel interface, so that only a few wires would be needed coming from the MSP430.
I've had thoughts of something similar with a uVAX-II board pair in a Qbus backplane for power: On power-up, an MPU would write code into RAM via the console ODT, then run it. But, it's only practical for smaller programs, and I can't think of what I would do with it...
One of the HP LED displays is shown in the lower-right corner, connected to the LS138. Those particular displays are sorta expensive today. I've got a few extra, but I'm not sharing .
The LS374 on the right side was not implemented. It was for adding output bits, but the clock doesn't need it.
The LS240 in the upper-left corner has two sections - one is for the T11 power-up config bits, the other is 4 bits of Input, selected by the "BTN" signal, which is addressed at the upper-most 1K page of the "B6" 8K page. Two bits are for the buttons, one is for the 3 Hz input (not shown on the drawing, I think it's pin 8 of the LS240), the 4th is unused.
The notations next to most chips pins, such as "3-24", are the row/column for the physical pin on the wire-wrap board I used.
Pete
One shows the time base used on the clock. Datasheets are on the web.
The other is for the T11 wire-wrap board. It's quite a mess...
The stuff in the lower-left corner (HC595's) was never implemented. It was a plan to make an interface that would be driven by a modern MPU, to DMA code into the RAM for the T11. I was going to use an MSP430. Every time on power-up, the MSP430 would load the T11's RAM and let it run. So, the T11 wouldn't need any EEPROM. The HC595's were a serial-to-parallel interface, so that only a few wires would be needed coming from the MSP430.
I've had thoughts of something similar with a uVAX-II board pair in a Qbus backplane for power: On power-up, an MPU would write code into RAM via the console ODT, then run it. But, it's only practical for smaller programs, and I can't think of what I would do with it...
One of the HP LED displays is shown in the lower-right corner, connected to the LS138. Those particular displays are sorta expensive today. I've got a few extra, but I'm not sharing .
The LS374 on the right side was not implemented. It was for adding output bits, but the clock doesn't need it.
The LS240 in the upper-left corner has two sections - one is for the T11 power-up config bits, the other is 4 bits of Input, selected by the "BTN" signal, which is addressed at the upper-most 1K page of the "B6" 8K page. Two bits are for the buttons, one is for the 3 Hz input (not shown on the drawing, I think it's pin 8 of the LS240), the 4th is unused.
The notations next to most chips pins, such as "3-24", are the row/column for the physical pin on the wire-wrap board I used.
Pete