FAQ
From Spare Time Gizmos' Wiki
- Some parts seem to be missing from my PCB!
R3, R4, R5 and J5 are never used and should not be installed. J2, J4, R6, D2 and D3 are used only if the VT6 is also installed. U10 and U11 and the associated bypass capacitors are used only when the memory is expanded to 1MW.
- I get output on my terminal but the input doesn't work...
If you aren't using the VT6, be sure you installed the jumper at D2 as directed in the assembly instructions. If you are using the VT6, be sure you installed the additional parts, especially D2, D3 and R6.
- Why does my 512kW SBC6120-RC says "448K memory" when it boots?
- Why does my 1MW SBC6120-RC says "960K memory" when it boots?
BTS6120 is reporting the size of the RAM disk, not the total memory. The HD6120 always reserves 32kW for main memory and 32kW for CP memory, so 512kW minus 64kW gives 448kW and 1MW minus 64kW is 960kW.
- Can I plug an ATA/IDE disk into J5?? It has the right number of pins...
Absolutely not! The SBC6120-RC has no IDE/ATA port and J5 is most certainly not wired for one. If you try to plug a disk or CF card into J5, it'll never work and you'll probably fry something. If you want to know more, see the next question.
- What's J5 for??
The original purpose was to make it easy for me to plug in a Logic Analyzer while I was debugging the initial design. You could always use it for the same if you had a problem to debug. Many people will ask "Couldn't it be used for an expansion board?" - the answer is "possibly". Most or all of the necessary interface signals are there and a clever person could probably work something out, but at the present time Spare Time Gizmos has no plans to offer expansion cards for the SBC6120-RC.
