Re: A few (more) IIgs questions.

[Rubywand <rubywand@swbell.net>]

Labelas Enoreth writes ...
> 
> In article <37BCBE09.694C6679@swbell.net>, rubywand@swbell.net wrote:
 ....

> >  If you get the board with all 4MB installed (i.e. do not have to hunt for
> > the RAM chips), the AE GS-RAM III is probably the best IIgs 4MB expansion
> > memory card ever produced.
> Cool. I can't imagine wanting to try to find those bizarre chips, I bet it
> would be hellish.
> 
     It does seem to be fairly difficult to find the 20-pin "Zip" package RAMs.


 ....

> > >
> > > ECHO Commander. What is the DIN...uh, 5...plug for?
 ....
> >      One clue would be the numbers on the major IC's on the board.
> well, I think that there was a cable to hook directly to the IIe-style
> speaker pin, but I'll double-check...but what sort of sound output goes on
> a DIN connector? Maybe I'm out of it, but...
> 
> Here is a description of the card...
> 
> Echo� Commander
> (big square logo with two rectangles through it)
> �1986 Street Electronics Corp
> J1-2-pin connection to Speaker
> U1-TSP5220CNL QCU8719 6163 (TI logo)
> U2-74LS373 PC (stylized f logo)
> U3-74LS373 PC (stylized f logo)
> U4-PS712 MM74C74N (two zigzags like lightning bolts, parallel)
> U5-T74LS02B1 98701 (SGS logo)
> U6-705 B B TL084CN (TI logo. Silver IC...(resistor network?))
> U7-SM8730 LM380N (two zigzags like lightning bolts, parallel)
> 5-pin molex connector to DIN-5 connector on rear
> 
> Pins 19, 24, 25, 26 on 'front' of card edge. (from left)
> Pins 1,2,3,6,9,16-25 on 'back' of card edge (from left)
> All others N/C

     This looks like a pure speech card. The TI 5220 is the speech IC.

     The place to look for an output is the LM380; it's the power amp IC. (The
two zigzags are the National Semiconductor logo.)

     For a 14-pin package, the output pin should be pin 8. Most circuits seem to
connect the output to an electrolytic capacitor which then connects to the 'hot'
speaker lead. The other speaker lead goes to ground.

     If the molex goes to the DIN, the board probably offers the option of
connecting internally to the IIe speaker (using the cable you mention) or
connecting to an external speaker using the DIN socket.

     Once you locate the LM380 output, you can probably connect an external
speaker and get it to output speech. 

     The only docs I know about are for the "Echo" which uses the 5200. You can
find them (R012echo.txt) on one of the Text FAQs sites (Ground, USWUG, ACN
Florida, ACN Tarnover, ...) or in html at Ground or
http://home.swbell.net/rubywand/R012echo.htm .



Rubywand