Hi all,
Now that my Replica 1 Ten has a basic compliment of I/O peripherals (ASCII keyboard, monitor, and CFFA1), I'm thinking of adding a slot expander.
Comparing Vince Briel's no-longer-available Slot Expander 1 with Speedy G's Slotexpansioncard and Wendell Sander's Apple 1 Expansion Board, I have a couple of takeaways:
- Vince's board appears to be a set of expansion slots in series with no additional components (other than the 40-pin header needed for the original Replica 1)
- Speedy and Wendell's boards appear to use additional components to address the buffering, power regulation, and VMA line isolation needed by original Apple-1s and full-size replicas.
Is it reasonable to assume that, given that the Propeller chip handles all I/O, that a wire wrap board with an edge connector and 44-pin slots wired in series would function properly with my Replica 1 Ten? Or am I mssing key considerations around buffering, regulation, and isolation?
P.S. I fully understand that the Replica 1 doesn't provide -12v and that cards that required -12v would require me to add an additional power supply and that might, in turn, require regulation. So, let's assume no -12v for any cards in my system.
Thanks—Jameson
The 44-pin bus exposes the address and data bus directly. How is the Propeller involved?
As far as wire-wrapping in general, my wire-wrap processor section worked fine. I used buffers for the 44-pin connector, but all I used it for was to make a single-step board with LED status.
Tom,
Thanks for the correction regarding the Propeller chip and for sharing that link. I'll give it a closer look.
Jameson