William Levak wrote:
>
> On Fri, 7 Jul 2000, Bo Zimmerman wrote:
>
> > I recently received an SFD-1001 with drive select switches. I went poking
> > around inside the drive and found some things I don't quite understand. I
> > noticed that the SFD-1001 has no less than TWO 6502 processors. One on the
> > main board, and another on a small daughterboard above the main board. In
> > addition, the main board has two 6532s (for the iEEE-488 bus, I expect), but
> > the daughterboard also has a 6522 near the 6502, and two other chips
> > besides, marked 251257-02a, and 901885-04. One is a 24pin 2k eeprom.
> >
> > I'm curious about a couple of things: whats the 6522 for? Why does a
> > single drive need two 6502s, and why the daughterboard?
>
> Those chip positions do not seem right. See my parts list on funet for
> the correct chip placement.
>
> Basically, the SFD-1001 is a 8250LP with one of the drives missing. The
> IEEE488 drives all have two processors,
except the 2031 lp, which has a single 6502A (not MOS... "S"...
synertek? strange...) and two 6522s no 6532s...
if into hardware: PCB NO 1540038 REV A W-1894HB (C) 1981 made in japan
--
01000011 01001111 01001101 01001101 01001111 01000100 01001111 01010010 01000101
Larry Anderson - Sysop of Silicon Realms BBS (209) 754-1363
300-14.4k bps
Classic Commodore pages at: http://www.jps.net/foxnhare/commodore.html
01000011 01001111 01001101 01010000 01010101 01010100 01000101 01010010 01010011
-
This message was sent through the cbm-hackers mailing list.
To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tcm.hut.fi.
Archive generated by hypermail 2.1.1.