This is a description of the original CBM IEEE-488 cartridge "VIC-1112" 
for the VIC20, and of the following files:

README            -  this text
schematics.ps     -  schematic diagram (PostScript)
schematics.tif    -  schematic diagram (TIFF)
325329-04.bin     -  EPROM (4 kB, raw binary)

I've drawn the schematics from my own 2 IEEE-488 modules. The print on the 
board is "P/N NO. 1110009 REV.A", "COPYRIGHT 1981". 

U1: M53217 or 7417, 6 buffers (open collector). 2 are used to drive the lines 
    EOI and IFC of the IEEE-488 bus, the other 4 are free.
U2: EPROM 2516, 2 kB, label "325329-04", or ROM "325329-03" (same contents).
U3: 74LS00, 4 NAND gates, all used.
U4, U5: MOS 6522 VIA
U6, U7, U8: MC3446, quad driver / receiver for IEEE-488 General Purpose 
    Interface-Bus (GPIB)

The ROM / EPROM is located at $B000 ... $B7FF. No autostart. Start with 
SYS 45065 (= 11*4096+9 = $B009)

The VIAs are located at $9200 ... $920F (U4) and $9210 ... $921F (U5).


july 1999, Wolfgang Guenther (woll@informatik.uni-bremen.de)