[comp.sys.atari.st] plugboards for the cartridge port

st69@sdcc12.UUCP (03/04/87)

Does anyone know of any prototyping boards that will plug into the
catridge slot of the ST?  It seems to need a 40-pin card edge with a
center spacing of ~0.08 inches, something which neither Augat or
Vector make.

thanks in advance,

Tom Erbe (uucp: sun!sdcarl!tre, genie: T.ERBE)

jpexg@mit-hermes.AI.MIT.EDU (John Purbrick) (03/06/87)

In article <788@sdcc12.ucsd.EDU>, st69@sdcc12.ucsd.EDU (Este Sikstinon) writes:
> Does anyone know of any prototyping boards that will plug into the
> catridge slot of the ST?  It seems to need a 40-pin card edge with a
> center spacing of ~0.08 inches, something which neither Augat or
> Vector make.
> Tom Erbe (uucp: sun!sdcarl!tre, genie: T.ERBE)

I made one of these by cutting a piece of circuit 
board to the right size, then cutting the correct 
pattern into it with an Xacto knife. It looks pretty
horrible and has a tendency to cause crashes by shorting
adjacent traces together (it's hard to be very accurate
with the knife), but it does work. Didn't the ubiquitous
Mr Braner tell us about reconnecting wires to make the
cartridge port writable, some time ago?

The contact fingers on the cartridge are on 2 milimeter spacing.

braner@batcomputer.tn.cornell.edu (braner) (03/08/87)

[]

I had to etch my own connector for the cartridge port.  I still
don't know of a commercially available card, besides some rather
expensive cards designed for EPROMs (rather than prototyping).
And by the way: the pitch is NOT exactly 2mm!

- Moshe Braner

PS: My proposed cartridge port mod was to cut pins 1, 39 and 40 (they
are redundant gnd and 5V lines), and connect pin 1 to the CPU R/W line,
pin 40 to the CPU clock, and pin 1 to a decoded address strobe generated
by a chip mounted inside the ST that passes the CPU AS line but only
when the address is in the 3-plus-epsilon-megabytes range.  This arrangement
lets me do full-speed writing to the port, while maintaining the port's
utility for standard plug-ins (once you cut those pins inside the plug-in!).
(I use the port for a homemade floating-point device with a 32081 chip.)

tech@usceast.UUCP (03/09/87)

In article <367@batcomputer.tn.cornell.edu> braner@batcomputer.UUCP (braner) writes:
>
>PS: My proposed cartridge port mod was to cut pins 1, 39 and 40 (they
>are redundant gnd and 5V lines), and connect pin 1 to the CPU R/W line,
>pin 40 to the CPU clock, and pin 1 to a decoded address strobe generated
>by a chip mounted inside the ST that passes the CPU AS line but only
>when the address is in the 3-plus-epsilon-megabytes range.  This arrangement
>lets me do full-speed writing to the port, while maintaining the port's
>utility for standard plug-ins (once you cut those pins inside the plug-in!).
>(I use the port for a homemade floating-point device with a 32081 chip.)

	Have you decided if you are going to post the math interface to
the net? I think it most interesting. I would like to follow up on this
for some image processing software that could use the resolution and
support. 

			Bill Wood(!usceast!tech)

st69@sdcc12.ucsd.EDU (Este Sikstinon) (03/09/87)

.
Thanks for all the help finding a board that will plug into the
cartridge port.  I finally was informed through email of a company
that makes a eprom board (which I will adapt) that is made for the
ST.  The company is Douglas Electronics in San Leandro, CA
(415-483-8770).  The part number is 33-DE-40.  And the price is only
$10.00.

Tom Erbe (uucp: ucbvax!sdcarl!tre, genie:T.ERBE)