4 Jun
2014
4 Jun
'14
12:33 p.m.
I recall my reaction when I read about Victor's
rather arcane scheme for
their recording in one of the electronics trade mags. Plain GCR would
have gotten them over 1MB on a double-sided 96 tpi DSDD floppy. We
figured it must have been hangover from the Commodore days. I was
The encoder/decoder circuit is almsot indentical to that in the 8050,
etc. I've not dumped the ROM (whcih is a look-up table for said circuit, not
firmware for any microprocessor) to see if that's the saem, but it may
well me
surprised that they didn't try to fit a 6502 in as
a disk controller.
:-) Heck, the 8050 has a pair of 6502s with shared memory...
There are 6 off 6522 VIAs in the Sirius. 3 on the motherboarf (system
control, printer port, and user port), and another 3 on the disk
controller board (I forget the exact allocation of the port pins). A
somewhat oddd choice for an 8088 machine, but then again the Intel
parallel port IC (8255) was broken as designed.
-tony