[Coco] Card edge numbering

[Shane Broadbent]

Mark J. Blair <nf6x at ...> writes:

> 
> 
> On Apr 14, 2014, at 18:23 , Brian Goers <briang0671 at ...> wrote:
> > I can not find my information on the card edge numbering.
> > I am fairly sure it's pin (1) on the component (top) side closest to the
back of the computer.
> 
> Correct. Odd numbers are on top, even numbers are on bottom.
> 
> > But I would like to have a drawing of it.
> > Anyone know where I would find one?
> 
> Well, sort of... If you look at the files "Top.png" and "Bottom.png" in my
CoCoEPROMpak project (see link
> below), the pin numbers for pins 1, 2, 39 and 40 are silk-screened on the
board for reference. Note that
> "Bottom.png" is looking through the board from the top side, so it's mirrored.
> 
> https://github.com/NF6X/CoCoEPROMpak
> 
> Since the board works, I probably got the pin numbering right! :)
> 

Page 102 of 'Tandys Little Wonder 2nd Edition"

Cartridge Port (Expansion) Connector
Looking "in" at the connector on the CoCo, odd numbered
pins are on top from right to left, even numbered pins on
bottom from right to left (39&40 on left, 1&2 on right):

PIN# DESCRIPTION
1 -12V, 100mA (CoCo 1 only)
2 +12V, 300mA (CoCo 1 only)
3 HALT input to CPU (normally low)
4 NMI (non-maskable interrupt, normally low)
5 RESET to CPU (normally low)
6 E clock signal (main)
7 Q clock signal (leads E)
8 CART (cartridge detect interrupt, normally low)
9 +5v, 300mA (all models)
10-17 D0-D17 (consecutivly numbered, data bits)
18 R/W (read/write signal to/from port, high on write)
19-31 A0-A12 (consecutivly numbered, address bits)
32 CTS (cartridge select, normally low)
33-34 Signal ground
35 Sound output
36 SCS (spare cartridge select, normally low)
37-39 A13-A15 (consecutivly numbered, address bits)
40 SLENB (disables internal device selection, normally
low); allows decoded but unused sections of
RAM to be used by external devices.