Memory OrganizationMain Memory is wired for 16 bits data path. Addressing one byte separately is not possible in the Heritage-1.
When reading larger numbers (such as a 32 bits Long), the least significant word comes first, that is the smaller address corresponds to the least significant word composing the number.
Memory chips (either RAM or ROM) can be distributed in any manner within the addressable space, except for the following:
- The very first block of 512 words (00000-001ff) must be populated since interrupt vectors are pointing there. It is recommended to populate the entire 1 Kw page frame (00000-003ff).
- Not the entire (1Mw) addressable space can be filled with physical memory because peripherals are memory mapped. It is recommended to preserve 1Kw (the size of a page frame) for peripheral addresses, aligned respect to all other page frames.
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Homebuilt CPUs WebRing
JavaScript by Qirien Dhaela
Join the ring?
David Brooks, the designer of the Simplex-III homebrew computer, has founded the Homebuilt CPUs Web Ring. To join, drop David a line, mentioning your page's URL. He will then add it to the list.
You will need to copy this code fragment into your page.
Project start date: May 13 of 2009
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