>I have been mulling over getting the elf2k kit from Sparetimegizmos,
>and I have decided to make the plunge. The questions I have;
>1)is it possible in addition to the hex leds to add a string of 8 leds
>for data, and 16 leds for address?
>2)I would like to also add memory read/write leds and possibly i/o
>flags, requests, and commands, etc.
>Since this a 30 year old computer I thought it would be cool to add
>lights similar to Imsai ot Altairs, etc. The only problem I am not
>strong enough in electronics to add these circuits.
Pretty much any book on microprocessor interfacing will show you various
ways to wire up LEDs to a microprocessor. Chips like the CD4049, 74HC373 or
74HC174, or lots of others are popular LED drivers.
Electrically, adding these LEDS to the ELF2K is pretty easy, but it may be
mechanically challenging, as least if you plan to use my PC board. You'll
have to build a separate board with all the LEDs and drivers, and then run a
bunch of jumper wires to the ELF2K board. You could pick up a lot of the
signals you need (like all the address and data lines) by making ribbon
cables with DIP connectors that go to the two 74HC244 sockets on the ELF2K
board. Many of the other signals you want are on the I/O connector.
Personally, I find that the six TIL311s satisfy my needs for blinky lights