The
single-density controller does indeed have 256 byte of ROM (in three chips!)
The double-density one has 512 bytes of ROM.
the boot rom was two 256x 4 parts (bipolar) and the third was the address
decode for the board (also 256x4 bipolar).
Ah yes - I was thinking of the fact that there are three of those
tough-to-find / tough-to-program 74S287 PROMS on the board,
but you are correct - only two of them are for the boot code.
Dave
--
dave06a (at) Dave Dunfield
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