Click the Keyboard icon?

[Dan]

I'm trying to test the HDL for the computer memory. The test script goes until it needs keyboard entry. The program then asks me to "Click the Keyboard icon and hold down the 'K' key ..."

There is no keyboard icon, that I can find. No matter how I switch the views, I cannot find a keyboard icon in Hardware Simulator.

[cadet1620]

Select "Screen" from the "View" drop-down list.  Underneath the bitmap output screen in the upper-right quarter of the screen, there should be a wide button with a keyboard icon.

--Mark

[Dan]

I'm truly not seeing it.

Here's a screenshot: http://i.imgur.com/5g8bL.png

[cadet1620]

You are running into a bug in the hardware simulator.  When you have more than one RAM/ROM parts in your design the windows get rearranged into this scrambled order.  Your Memory.hdl should have ROM32K, RAM16K and Screen as the only memory components. What are you trying to do with the extra two RAM4K parts?  

--Mark

[Dan]

Oh, I must've read the spec wrong. I was using the 4K chips as the screen memory map and an add'l register for the keyboard. I built a DMux/Mux logic for it.

I'll have to take another look in light of what you've said. Thanks.

[Dan]

Okay, the problem that I have now is that I'm being asked to use the Keyboard and Screen chips which I have no idea the input/output pins on.

[Dan]

Sorry, I actually figured this one out by myself. I forgot all about the built ins directory.

[cadet1620]

For others who may be looking for them, Screen and Keyboard are documented in figures 5.4 - 5.6.

--Mark

[David Rysdam]

Oh, I did the exact same thing! I'm glad I came here to see what was up before struggling with it too long.

I have to say that I found this chapter very badly organized. In previous chapters, all the "gray boxes" are projects but in this one most of the gray boxes are simply documentation. And the projects are presented out of order from the suggested working order.

[shubham1172]

Haha, I ended up doing the exact thing! I guess the course should have made us write our own memory maps for IO as well!

[tomthestrom]

Run into the same problem...
Used a 16K RAM
2x 4k RAM for the Screen
1x Register for the Keyboard

I did not assume I should use built-ins.  
Grateful for this thread!

Awesome book by the way :)

[WBahn]

While I would agree that the authors could have made this more pointed, the instructions pretty clearly said that the Memory part is built from a RAM16K, a Screen, and a Keyboard part. Thus, to not use the built-in parts you would have to build your own Screen and Keyboard parts that exhibit the behavior for those parts as specified in Figures 5.4 and 5.5, so hopefully the awareness that this isn't something that can be done (with the given parts to build from) should have occurred before even attempting to build the Memory part that uses them.

Making this clear in the comments in the descriptions of those two parts would have been a good idea. But that the built-in parts are to be used was made explicit in the very first "Step" of the Project section (Section 5.5) where it says, "The Screen and the Keyboard are available as built-in chips and there is no need to build them."