[sebhc] Can I have BBQ Sauce with my foot...
waltm22 at comcast.net
Sun May 23 17:47:26 CDT 2004
I told you I might be putting my foot in my mouth, so here it goes...
Who supplies the code at 030.000 when you only have an H-47 installed?
Heathkit wasn't explicit about this. They tell you that you must have the
HA8-8 extended configuration board installed to run the H-47. What they
don't mention in the manual is that you must also have implemented the ORG-0
functionality - both the new ROM on the motherboard and RAM at 000.000.
Why? Because the ROM is actually 4K, and contains the H-17 ROM at address
010.000. When there is RAM present at 000.000, the ROM image at 010.000 is
copied to RAM at 030.000. When there is no RAM at 000.000, no copy is done,
none of the 030.xxx routines get installed, no booting occurs, on either the
H-47 or the H-17 (from my tests).
So there are some dependencies on the H-17 ROMs to boot; now I need to find
them. I still believe that it would be easy to trap at the read/write
vectors and not have to emulate the disk at the I/O level, I just need to
figure out how.
Jack - I guess the 444-70 ROM image in the archives is incorrect since it
only contains the XCON/RAM8GO code, and not the 030.000 binary. I am also
very curious about any differences between the H-17 ROM and the version
contained with the XCON/RAM8GO ROM.
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