16 Feb
2007
16 Feb
'07
4:29 a.m.
B. Degnan wrote:
Are the programs from the SWTPc 6800 interchangeable
with the Altair
680? Is there a good web reference that compares these two?
there are several differences that affect interchange between
the mits 680 and the swtpc
the acia address is $F000 in mits
swtpc uses a bit banging PIA at $8004
swtpc uses the mikbug monitor ROM, mits uses a custom
monitor rom that looks a lot like minibug.
(later swtpc systems used SWTBUG and an ACIA)
swtpc has a scratchpad RAM at $A000 mits has all RAM
contigous starting at $0000
swtpc runs at aprox. 900kHZ mits runs at 500KHZ
mits has a configuration register at $F002 swtpc doesn't have one.
both systems use KC standard cassette at 300baud and motorola
S1-S9 records
joe