Re: tiny COBOL, Article on new mainframe use

Stefan Monnier <monnier@iro.umontreal.ca> writes:

A C64 had 64K 8-bit bytes of RAM,

>
Indeed (tho, IIRC 8kB of those were hidden by the ROM, tho you could
change the mapping to hide different 8kB at different time and thus
access the full 64kB of RAM).

Actually, the C64 has 8+8KB of ROM (at $a000-$bfff and at
$e000-$ffff), and I/O at $D000-$DFFF and at $0-$1 that hide the RAM in
the default configuration.  You could configure the "MMU" to make all
RAM except the two locations at $0-$1 readable and writeable for the
CPU, but of course then you would have to bank-switch to access the
I/O or the OS (in the ROM at $e000-$ffff), so the common setup even if
BASIC was not needed was to have the I/O and the OS ROM visible, and
48KB of contiguous RAM readable and writable.

and the floppies held about 1.2MB but they were a
whole lot cheaper than 1311 disk packs.

>
IIRC they held only ~170kB.

Yes, the 1541 gave us 170KB at a time.  Much later there was also the
1571, which was double-sided and thus doubled the capacity, and even
later the 1581 which gave 790KB of storage.  I stuck with the 1541,
for which I have an accelerator add-on.

- anton
--
'Anyone trying for "industrial quality" ISA should avoid undefined behavior.'
  Mitch Alsup, <c17fcd89-f024-40e7-a594-88a85ac10d20o@googlegroups.com>