[FRAM71] Pre-Production Batch

[Hans Brueggemann]

bob, that is what i had hoped for, because i need the extra bytes in the configuration area...
V430 is hiding now on my hard disk, REDEYE and UART abandoned, but having access to 15 out of 16 32kB blocks. no, it's not ready for release, though ;o)
instead of having one nibble per chip in the 2C000 area, each chip now has one configuration byte.
in V420,
having at 2C000 the 4 nibbles "9999" meant "4 Memory modules, 32k each, living at HP-71B's address range 30000-6FFFF", whereas at the same time the FRAM base addresses were fixed at 30000, 40000, 50000, 60000, respectively.
in V430 however,
you would instead program at 2C000 the value "9a9b9c9d", where a,b,c,d are constants in the range of "0".."F" (except "2", that is) that program the FRAM's base addresses in 32k steps. hence, programming "93949C9A" into 2C000 would still deliver 4 memory modules at the same address range in HP-71's world, but would actually use the internal FRAM-blocks at 30000, 40000, C0000, A0000. and by changing the constants only, you can now map different FRAM contents into the same HP-71B address range.
(big caveat: though the above example shows RAM modules, you would do this with ROMs only in order to keep the file chain intact.)

hans,
awaiting more votes on the "drop REDEYE, UART" case