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- ************************************************************************
- How to upgrade your 24oo modem into a 96oo baud. (US Robotics compatible
- of course
- Written B
- Death Bringer (CPT/Info-Net/IRA
-
- 06/7/9
-
-
- Be sure to turn off your modem before you begin
-
- First of all, you need to go to your nearby electronics store, don't tr
- to go to Radio Shack, their parts have their own model numbers and you'l
- have a hell of a time getting the parts you need. This upgrading of you
- modem will not work on old hayes modems, but they will work on any clon
- maker of modems (everex, practical peripherals, anchor, ati, intel, etc.
- It will only work with modems with the Intel Chipset
-
- This technique widens the band width by using a different chip that i
- similiar to the chip already in your modem
-
- Parts Needed
- 16550 UAR
- L4313545 I
- SC11020CN I
- L8730183 I
-
- First of all, check to see if your biggest chips are soldered or socketed
- if they are soldered, you'll have to de-solder the chips before you begin
- After you get that done, replace the 8250 UART with the 16550 UART. (1655
- UARTs are required for 9600+ speeds). The other 1 or 2 chip(s) need(s
- to replaced with INTEL L4313545 instead of the chip that is already there
- If your modem has another socket or more, than you are in luck, you ca
- purchase a chip from US Robotics, and make your modem faster than 9600
- If you don't have the socket, than you can only go 9600. I'll get th
- chip number to you in the next edition and explain how and where t
- install it. I am working on a way for the people (like me) that do not hav
- the extra socket in their modem to speed up the rates. I am working on a wa
- to piggy back the chip. I'll get back to you. There should be a 22 pi
- chip on your modem also with a model number of SC11005CN or some where clos
- to it. Replace it with the SC11020CN. Also, replace the L8630173 with th
- L8730183 chip. If you have any suggestions or questions, you can locate me
- through Compuserve USER ID 74702,9752
-
- *****OPTIONAL, LAP-M Error correction****
-
- Adding error correction is rather simple. For this these parts ar
- necessary
-
- Potentiometer. This is a 5k audio taper variable resistor
-
- Capacitor. Any non-polarized 1.0 to 1.5 uf cap should do
-
- 100 ohm resistor - quarter or half watt
-
- Wir
-
- Solder, soldering iron, etc
-
- Solder one end of the capacitor to PIN 1 of the phone line input jac
- |-------------------
- | \ line in :
- | \ phone in :
- |-----------||||||||| pin 1
-
-
-
- If your modem is external, the diagram looks like this
-
-
- |------------------
- | /
- | ||RS-232 por
- | \| :
- | |-|line in :
- | |-| pin 1
- | |-|phone i
- | |-
- |------------------
- This should be on the back of the modem
- Pin one should the farthest on the bottom left
-
- Solder the other end of the capacitor to the center lug of the potentiomete
- (there are three lugs on this critter). Solder one end of the resistor to th
- PIN 4 of the line input jack. Solder the other end of the resisto
- to either one of the remaining outside lugs of the potentiometer. Doesn'
- matter which one
-
- ------------------------------------------------------------------------
-
- ADDITION TO ORIGNAL FILE - 6/15/91
- Bill McCauley & Dark Spyre/Dr. Brains/Ryan Schwartz/Lamer/Lose
-
- First, a personal recomendation. _THIS WORKS!!!_ I have been plagued wit
- 2400 baud for some time. I hate waiting for the transfer to finish so tha
- i can use the phone. Threw the gismo together in about 10 or 15 minutes
- took another five to adjust the pot for best results on my wors
- conection, and guess what? No more slow connections
-
- ------------------------------------------------------------------------
-
- Have Fun
- of course
-
- I am working on cheap ways to install V.32/V.42bis on your modified mode
-
-
- **************